diff --git a/AllTests-mainnet.md b/AllTests-mainnet.md
index 043a8eb15..1047dc9c7 100644
--- a/AllTests-mainnet.md
+++ b/AllTests-mainnet.md
@@ -5,7 +5,6 @@ AllTests-mainnet
 + BASE_REWARD_FACTOR                                64                   [Preset: mainnet]   OK
 + BLS_WITHDRAWAL_PREFIX                             "0x00"               [Preset: mainnet]   OK
 + CHURN_LIMIT_QUOTIENT                              65536                [Preset: mainnet]   OK
-  CONFIG_NAME                                       "mainnet"            [Preset: mainnet]   Skip
   DEPOSIT_CHAIN_ID                                  1                    [Preset: mainnet]   Skip
   DEPOSIT_CONTRACT_ADDRESS                          "0x00000000219ab540356cBB839Cbe05303d770 Skip
   DEPOSIT_NETWORK_ID                                1                    [Preset: mainnet]   Skip
@@ -63,7 +62,7 @@ AllTests-mainnet
 + VALIDATOR_REGISTRY_LIMIT                          1099511627776        [Preset: mainnet]   OK
 + WHISTLEBLOWER_REWARD_QUOTIENT                     512                  [Preset: mainnet]   OK
 ```
-OK: 51/60 Fail: 0/60 Skip: 9/60
+OK: 51/59 Fail: 0/59 Skip: 8/59
 ## Attestation pool processing [Preset: mainnet]
 ```diff
 + Attestations may arrive in any order [Preset: mainnet]                                     OK
@@ -323,4 +322,4 @@ OK: 3/3 Fail: 0/3 Skip: 0/3
 OK: 1/1 Fail: 0/1 Skip: 0/1
 
 ---TOTAL---
-OK: 180/189 Fail: 0/189 Skip: 9/189
+OK: 180/188 Fail: 0/188 Skip: 8/188
diff --git a/FixtureAll-mainnet.md b/FixtureAll-mainnet.md
index c33e68517..67f165c68 100644
--- a/FixtureAll-mainnet.md
+++ b/FixtureAll-mainnet.md
@@ -24,9 +24,11 @@ FixtureAll-mainnet
 + Rewards - full_random_0 [Preset: mainnet]                                                  OK
 + Rewards - full_random_1 [Preset: mainnet]                                                  OK
 + Rewards - full_random_2 [Preset: mainnet]                                                  OK
++ Rewards - full_random_3 [Preset: mainnet]                                                  OK
 + Rewards - full_random_five_epoch_leak [Preset: mainnet]                                    OK
 + Rewards - full_random_leak [Preset: mainnet]                                               OK
-+ Rewards - full_random_low_balances [Preset: mainnet]                                       OK
++ Rewards - full_random_low_balances_0 [Preset: mainnet]                                     OK
++ Rewards - full_random_low_balances_1 [Preset: mainnet]                                     OK
 + Rewards - full_random_misc_balances [Preset: mainnet]                                      OK
 + Rewards - full_random_ten_epoch_leak [Preset: mainnet]                                     OK
 + Rewards - half_full [Preset: mainnet]                                                      OK
@@ -84,12 +86,16 @@ FixtureAll-mainnet
 + [Invalid] att2_high_index                                                                  OK
 + [Invalid] bad_source_root                                                                  OK
 + [Invalid] before_inclusion_delay                                                           OK
++ [Invalid] correct_after_epoch_delay                                                        OK
 + [Invalid] empty_participants_seemingly_valid_sig                                           OK
 + [Invalid] empty_participants_zeroes_sig                                                    OK
 + [Invalid] epochs_are_different                                                             OK
 + [Invalid] future_target_epoch                                                              OK
 + [Invalid] headers_are_same_sigs_are_different                                              OK
 + [Invalid] headers_are_same_sigs_are_same                                                   OK
++ [Invalid] incorrect_head_after_epoch_delay                                                 OK
++ [Invalid] incorrect_head_and_target_after_epoch_delay                                      OK
++ [Invalid] incorrect_target_after_epoch_delay                                               OK
 + [Invalid] invalid_attestation_signature                                                    OK
 + [Invalid] invalid_current_source_root                                                      OK
 + [Invalid] invalid_different_proposer_indices                                               OK
@@ -138,11 +144,6 @@ FixtureAll-mainnet
 + [Valid]    new_deposit_under_max                                                           OK
 + [Valid]    success_top_up                                                                  OK
 + [Valid]    valid_sig_but_forked_state                                                      OK
-+ [Valid]   Official - Finality - finality_no_updates_at_genesis [Preset: mainnet]           OK
-+ [Valid]   Official - Finality - finality_rule_1 [Preset: mainnet]                          OK
-+ [Valid]   Official - Finality - finality_rule_2 [Preset: mainnet]                          OK
-+ [Valid]   Official - Finality - finality_rule_3 [Preset: mainnet]                          OK
-+ [Valid]   Official - Finality - finality_rule_4 [Preset: mainnet]                          OK
 + [Valid]   Official - Sanity - Blocks - attestation [Preset: mainnet]                       OK
 + [Valid]   Official - Sanity - Blocks - attester_slashing [Preset: mainnet]                 OK
 + [Valid]   Official - Sanity - Blocks - balance_driven_status_transitions [Preset: mainnet] OK
@@ -166,27 +167,50 @@ FixtureAll-mainnet
 + [Valid]   Official - Sanity - Blocks - skipped_slots [Preset: mainnet]                     OK
 + [Valid]   Official - Sanity - Blocks - slash_and_exit_diff_index [Preset: mainnet]         OK
 + [Valid]   Official - Sanity - Blocks - voluntary_exit [Preset: mainnet]                    OK
++ [Valid]   correct_epoch_delay                                                              OK
++ [Valid]   correct_min_inclusion_delay                                                      OK
++ [Valid]   correct_sqrt_epoch_delay                                                         OK
 + [Valid]   default_exit_epoch_subsequent_exit                                               OK
++ [Valid]   incorrect_head_and_target_epoch_delay                                            OK
++ [Valid]   incorrect_head_and_target_min_inclusion_delay                                    OK
++ [Valid]   incorrect_head_and_target_sqrt_epoch_delay                                       OK
++ [Valid]   incorrect_head_epoch_delay                                                       OK
++ [Valid]   incorrect_head_min_inclusion_delay                                               OK
++ [Valid]   incorrect_head_sqrt_epoch_delay                                                  OK
++ [Valid]   incorrect_target_epoch_delay                                                     OK
++ [Valid]   incorrect_target_min_inclusion_delay                                             OK
++ [Valid]   incorrect_target_sqrt_epoch_delay                                                OK
 + [Valid]   success                                                                          OK
 + [Valid]   success_already_exited_long_ago                                                  OK
 + [Valid]   success_already_exited_recent                                                    OK
 + [Valid]   success_block_header                                                             OK
 + [Valid]   success_double                                                                   OK
 + [Valid]   success_exit_queue                                                               OK
++ [Valid]   success_low_balances                                                             OK
++ [Valid]   success_misc_balances                                                            OK
 + [Valid]   success_multi_proposer_index_iterations                                          OK
 + [Valid]   success_previous_epoch                                                           OK
 + [Valid]   success_slashed_and_proposer_index_the_same                                      OK
 + [Valid]   success_surround                                                                 OK
++ [Valid]   success_with_effective_balance_disparity                                         OK
 ```
-OK: 175/175 Fail: 0/175 Skip: 0/175
-## Official - Epoch Processing - Final updates [Preset: mainnet]
+OK: 191/191 Fail: 0/191 Skip: 0/191
+## Official - Epoch Processing - Effective balance updates [Preset: mainnet]
 ```diff
-+ Final updates - effective_balance_hysteresis [Preset: mainnet]                             OK
-+ Final updates - eth1_vote_no_reset [Preset: mainnet]                                       OK
-+ Final updates - eth1_vote_reset [Preset: mainnet]                                          OK
-+ Final updates - historical_root_accumulator [Preset: mainnet]                              OK
++ Effective balance updates - effective_balance_hysteresis [Preset: mainnet]                 OK
 ```
-OK: 4/4 Fail: 0/4 Skip: 0/4
+OK: 1/1 Fail: 0/1 Skip: 0/1
+## Official - Epoch Processing - Eth1 data reset [Preset: mainnet]
+```diff
++ Eth1 data reset - eth1_vote_no_reset [Preset: mainnet]                                     OK
++ Eth1 data reset - eth1_vote_reset [Preset: mainnet]                                        OK
+```
+OK: 2/2 Fail: 0/2 Skip: 0/2
+## Official - Epoch Processing - Historical roots update [Preset: mainnet]
+```diff
++ Historical roots update - historical_root_accumulator [Preset: mainnet]                    OK
+```
+OK: 1/1 Fail: 0/1 Skip: 0/1
 ## Official - Epoch Processing - Justification & Finalization [Preset: mainnet]
 ```diff
 + Justification & Finalization - 123_ok_support [Preset: mainnet]                            OK
@@ -200,6 +224,16 @@ OK: 4/4 Fail: 0/4 Skip: 0/4
 + Justification & Finalization - 23_poor_support [Preset: mainnet]                           OK
 ```
 OK: 9/9 Fail: 0/9 Skip: 0/9
+## Official - Epoch Processing - Participation record updates [Preset: mainnet]
+```diff
++ Participation record updates - updated_participation_record [Preset: mainnet]              OK
+```
+OK: 1/1 Fail: 0/1 Skip: 0/1
+## Official - Epoch Processing - RANDAO mixes reset [Preset: mainnet]
+```diff
++ RANDAO mixes reset - updated_randao_mixes [Preset: mainnet]                                OK
+```
+OK: 1/1 Fail: 0/1 Skip: 0/1
 ## Official - Epoch Processing - Registry updates [Preset: mainnet]
 ```diff
 + Registry updates - activation_queue_activation_and_ejection [Preset: mainnet]              OK
@@ -214,11 +248,17 @@ OK: 9/9 Fail: 0/9 Skip: 0/9
 OK: 8/8 Fail: 0/8 Skip: 0/8
 ## Official - Epoch Processing - Slashings [Preset: mainnet]
 ```diff
++ Slashings - low_penalty [Preset: mainnet]                                                  OK
 + Slashings - max_penalties [Preset: mainnet]                                                OK
++ Slashings - minimal_penalty [Preset: mainnet]                                              OK
 + Slashings - scaled_penalties [Preset: mainnet]                                             OK
-+ Slashings - small_penalty [Preset: mainnet]                                                OK
 ```
-OK: 3/3 Fail: 0/3 Skip: 0/3
+OK: 4/4 Fail: 0/4 Skip: 0/4
+## Official - Epoch Processing - Slashings reset [Preset: mainnet]
+```diff
++ Slashings reset - flush_slashings [Preset: mainnet]                                        OK
+```
+OK: 1/1 Fail: 0/1 Skip: 0/1
 
 ---TOTAL---
-OK: 199/199 Fail: 0/199 Skip: 0/199
+OK: 219/219 Fail: 0/219 Skip: 0/219
diff --git a/beacon_chain/spec/state_transition_epoch.nim b/beacon_chain/spec/state_transition_epoch.nim
index b527c56c8..477917c42 100644
--- a/beacon_chain/spec/state_transition_epoch.nim
+++ b/beacon_chain/spec/state_transition_epoch.nim
@@ -466,7 +466,7 @@ func process_slashings*(state: var BeaconState, total_balance: Gwei) {.nbench.}=
       decrease_balance(state, index.ValidatorIndex, penalty)
 
 # https://github.com/ethereum/eth2.0-specs/blob/dev/specs/phase0/beacon-chain.md#eth1-data-votes-updates
-func process_eth1_data_reset(state: var BeaconState) {.nbench.} =
+func process_eth1_data_reset*(state: var BeaconState) {.nbench.} =
   let next_epoch = get_current_epoch(state) + 1
 
   # Reset eth1 data votes
@@ -474,7 +474,7 @@ func process_eth1_data_reset(state: var BeaconState) {.nbench.} =
     state.eth1_data_votes = default(type state.eth1_data_votes)
 
 # https://github.com/ethereum/eth2.0-specs/blob/dev/specs/phase0/beacon-chain.md#effective-balances-updates
-func process_effective_balance_updates(state: var BeaconState) {.nbench.} =
+func process_effective_balance_updates*(state: var BeaconState) {.nbench.} =
   # Update effective balances with hysteresis
   for index in 0..<state.validators.len:
     let balance = state.balances.asSeq()[index]
@@ -493,14 +493,14 @@ func process_effective_balance_updates(state: var BeaconState) {.nbench.} =
           MAX_EFFECTIVE_BALANCE)
 
 # https://github.com/ethereum/eth2.0-specs/blob/dev/specs/phase0/beacon-chain.md#slashings-balances-updates
-func process_slashings_reset(state: var BeaconState) {.nbench.} =
+func process_slashings_reset*(state: var BeaconState) {.nbench.} =
   let next_epoch = get_current_epoch(state) + 1
 
   # Reset slashings
   state.slashings[int(next_epoch mod EPOCHS_PER_SLASHINGS_VECTOR)] = 0.Gwei
 
 # https://github.com/ethereum/eth2.0-specs/blob/dev/specs/phase0/beacon-chain.md#randao-mixes-updates
-func process_randao_mixes_reset(state: var BeaconState) {.nbench.} =
+func process_randao_mixes_reset*(state: var BeaconState) {.nbench.} =
   let
     current_epoch = get_current_epoch(state)
     next_epoch = current_epoch + 1
@@ -510,7 +510,7 @@ func process_randao_mixes_reset(state: var BeaconState) {.nbench.} =
     get_randao_mix(state, current_epoch)
 
 # https://github.com/ethereum/eth2.0-specs/blob/dev/specs/phase0/beacon-chain.md#historical-roots-updates
-func process_historical_roots_update(state: var BeaconState) {.nbench.} =
+func process_historical_roots_update*(state: var BeaconState) {.nbench.} =
   # Set historical root accumulator
   let next_epoch = get_current_epoch(state) + 1
 
@@ -524,7 +524,7 @@ func process_historical_roots_update(state: var BeaconState) {.nbench.} =
       raiseAssert "no more room for historical roots, so long and thanks for the fish!"
 
 # https://github.com/ethereum/eth2.0-specs/blob/dev/specs/phase0/beacon-chain.md#participation-records-rotation
-func process_participation_record_updates(state: var BeaconState) {.nbench.} =
+func process_participation_record_updates*(state: var BeaconState) {.nbench.} =
   # Rotate current/previous epoch attestations - using swap avoids copying all
   # elements using a slow genericSeqAssign
   state.previous_epoch_attestations.clear()
diff --git a/tests/official/fixtures_utils.nim b/tests/official/fixtures_utils.nim
index 8f597660e..459796f61 100644
--- a/tests/official/fixtures_utils.nim
+++ b/tests/official/fixtures_utils.nim
@@ -11,7 +11,8 @@ import
   # Internals
   ../../beacon_chain/ssz,
   ../../beacon_chain/spec/[datatypes, crypto, state_transition_epoch],
-  # Status libs
+  # Status libs,
+  snappy,
   stew/byteutils,
   serialization, json_serialization
 
@@ -28,7 +29,7 @@ export  # Workaround:
 # #######################
 # JSON deserialization
 
-proc readValue*(r: var JsonReader, a: var seq[byte]) =
+func readValue*(r: var JsonReader, a: var seq[byte]) =
   ## Custom deserializer for seq[byte]
   a = hexToSeqByte(r.readValue(string))
 
@@ -42,9 +43,10 @@ type
 const
   FixturesDir* =
     currentSourcePath.rsplit(DirSep, 1)[0] / ".." / ".." / "vendor" / "nim-eth2-scenarios"
-  SszTestsDir* = FixturesDir / "tests-v" & SPEC_VERSION
+  SszTestsDir* = FixturesDir / "tests-v1.1.0-alpha.5"
+  MaxObjectSize* = 3_000_000
 
-proc parseTest*(path: string, Format: typedesc[Json or SSZ], T: typedesc): T =
+proc parseTest*(path: string, Format: typedesc[Json], T: typedesc): T =
   try:
     # debugEcho "          [Debug] Loading file: \"", path, '\"'
     result = Format.loadFile(path, T)
@@ -65,6 +67,16 @@ proc sszDecodeEntireInput*(input: openArray[byte], Decoded: type): Decoded =
   if stream.readable:
     raise newException(UnconsumedInput, "Remaining bytes in the input")
 
+proc parseTest*(path: string, Format: typedesc[SSZ], T: typedesc): T =
+  try:
+    # debugEcho "          [Debug] Loading file: \"", path, '\"'
+    sszDecodeEntireInput(snappy.decode(readFileBytes(path), MaxObjectSize), T)
+  except SerializationError as err:
+    writeStackTrace()
+    stderr.write $Format & " load issue for file \"", path, "\"\n"
+    stderr.write err.formatMsg(path), "\n"
+    quit 1
+
 proc process_justification_and_finalization*(state: var BeaconState) =
   var cache = StateCache()
 
@@ -73,7 +85,7 @@ proc process_justification_and_finalization*(state: var BeaconState) =
   rewards.process_attestations(state, cache)
   process_justification_and_finalization(state, rewards.total_balances)
 
-proc process_slashings*(state: var BeaconState) =
+func process_slashings*(state: var BeaconState) =
   var cache = StateCache()
   var rewards: RewardInfo
   rewards.init(state)
diff --git a/tests/official/test_fixture_operations_attestations.nim b/tests/official/test_fixture_operations_attestations.nim
index fa43f43b3..14d5dfc54 100644
--- a/tests/official/test_fixture_operations_attestations.nim
+++ b/tests/official/test_fixture_operations_attestations.nim
@@ -34,7 +34,7 @@ proc runTest(identifier: string) =
   proc `testImpl _ operations_attestations _ identifier`() =
 
     var prefix: string
-    if existsFile(testDir/"post.ssz"):
+    if existsFile(testDir/"post.ssz_snappy"):
       prefix = "[Valid]   "
     else:
       prefix = "[Invalid] "
@@ -42,11 +42,14 @@ proc runTest(identifier: string) =
     test prefix & identifier:
       var cache = StateCache()
 
-      let attestation = parseTest(testDir/"attestation.ssz", SSZ, Attestation)
-      var preState = newClone(parseTest(testDir/"pre.ssz", SSZ, BeaconState))
+      let attestation =
+        parseTest(testDir/"attestation.ssz_snappy", SSZ, Attestation)
+      var preState =
+        newClone(parseTest(testDir/"pre.ssz_snappy", SSZ, BeaconState))
 
-      if existsFile(testDir/"post.ssz"):
-        let postState = newClone(parseTest(testDir/"post.ssz", SSZ, BeaconState))
+      if existsFile(testDir/"post.ssz_snappy"):
+        let postState =
+          newClone(parseTest(testDir/"post.ssz_snappy", SSZ, BeaconState))
         let done = process_attestation(preState[], attestation, {}, cache).isOk
         doAssert done, "Valid attestation not processed"
         check: preState[].hash_tree_root() == postState[].hash_tree_root()
diff --git a/tests/official/test_fixture_operations_attester_slashings.nim b/tests/official/test_fixture_operations_attester_slashings.nim
index 0abfb1fa6..3bbcbfc62 100644
--- a/tests/official/test_fixture_operations_attester_slashings.nim
+++ b/tests/official/test_fixture_operations_attester_slashings.nim
@@ -33,21 +33,25 @@ proc runTest(identifier: string) =
   proc `testImpl _ operations_attester_slashing _ identifier`() =
 
     var prefix: string
-    if existsFile(testDir/"post.ssz"):
+    if existsFile(testDir/"post.ssz_snappy"):
       prefix = "[Valid]   "
     else:
       prefix = "[Invalid] "
 
     test prefix & identifier:
-      var cache = StateCache()
+      let attesterSlashing =
+        parseTest(testDir/"attester_slashing.ssz_snappy", SSZ, AttesterSlashing)
+      var
+        cache = StateCache()
+        preState =
+          newClone(parseTest(testDir/"pre.ssz_snappy", SSZ, BeaconState))
 
-      let attesterSlashing = parseTest(testDir/"attester_slashing.ssz", SSZ, AttesterSlashing)
-      var preState = newClone(parseTest(testDir/"pre.ssz", SSZ, BeaconState))
-
-      if existsFile(testDir/"post.ssz"):
-        let postState = newClone(parseTest(testDir/"post.ssz", SSZ, BeaconState))
-        let done = process_attester_slashing(preState[], attesterSlashing,
-                                             {}, cache).isOk
+      if existsFile(testDir/"post.ssz_snappy"):
+        let
+          postState =
+            newClone(parseTest(testDir/"post.ssz_snappy", SSZ, BeaconState))
+          done = process_attester_slashing(preState[], attesterSlashing,
+                                           {}, cache).isOk
         doAssert done, "Valid attestater slashing not processed"
         check: preState[].hash_tree_root() == postState[].hash_tree_root()
         reportDiff(preState, postState)
diff --git a/tests/official/test_fixture_operations_block_header.nim b/tests/official/test_fixture_operations_block_header.nim
index 1e2008cc0..96aff4850 100644
--- a/tests/official/test_fixture_operations_block_header.nim
+++ b/tests/official/test_fixture_operations_block_header.nim
@@ -33,20 +33,23 @@ proc runTest(identifier: string) =
   proc `testImpl _ blockheader _ identifier`() =
 
     var prefix: string
-    if existsFile(testDir/"post.ssz"):
+    if existsFile(testDir/"post.ssz_snappy"):
       prefix = "[Valid]   "
     else:
       prefix = "[Invalid] "
 
     test prefix & identifier:
-      var cache = StateCache()
+      let blck = parseTest(testDir/"block.ssz_snappy", SSZ, BeaconBlock)
+      var
+        cache = StateCache()
+        preState =
+          newClone(parseTest(testDir/"pre.ssz_snappy", SSZ, BeaconState))
 
-      let blck = parseTest(testDir/"block.ssz", SSZ, BeaconBlock)
-      var preState = newClone(parseTest(testDir/"pre.ssz", SSZ, BeaconState))
-
-      if existsFile(testDir/"post.ssz"):
-        let postState = newClone(parseTest(testDir/"post.ssz", SSZ, BeaconState))
-        let done = process_block_header(preState[], blck, {}, cache).isOk
+      if existsFile(testDir/"post.ssz_snappy"):
+        let
+          postState =
+            newClone(parseTest(testDir/"post.ssz_snappy", SSZ, BeaconState))
+          done = process_block_header(preState[], blck, {}, cache).isOk
         doAssert done, "Valid block header not processed"
         check: preState[].hash_tree_root() == postState[].hash_tree_root()
         reportDiff(preState, postState)
diff --git a/tests/official/test_fixture_operations_deposits.nim b/tests/official/test_fixture_operations_deposits.nim
index f4d431584..446146177 100644
--- a/tests/official/test_fixture_operations_deposits.nim
+++ b/tests/official/test_fixture_operations_deposits.nim
@@ -33,17 +33,19 @@ proc runTest(identifier: string) =
   proc `testImpl _ operations_deposits _ identifier`() =
 
     var prefix: string
-    if existsFile(testDir/"post.ssz"):
+    if existsFile(testDir/"post.ssz_snappy"):
       prefix = "[Valid]   "
     else:
       prefix = "[Invalid] "
 
     test prefix & " " & identifier:
-      let deposit = parseTest(testDir/"deposit.ssz", SSZ, Deposit)
-      var preState = newClone(parseTest(testDir/"pre.ssz", SSZ, BeaconState))
+      let deposit = parseTest(testDir/"deposit.ssz_snappy", SSZ, Deposit)
+      var preState =
+        newClone(parseTest(testDir/"pre.ssz_snappy", SSZ, BeaconState))
 
-      if existsFile(testDir/"post.ssz"):
-        let postState = newClone(parseTest(testDir/"post.ssz", SSZ, BeaconState))
+      if existsFile(testDir/"post.ssz_snappy"):
+        let postState =
+          newClone(parseTest(testDir/"post.ssz_snappy", SSZ, BeaconState))
         discard process_deposit(defaultRuntimePreset, preState[], deposit)
         reportDiff(preState, postState)
       else:
diff --git a/tests/official/test_fixture_operations_proposer_slashings.nim b/tests/official/test_fixture_operations_proposer_slashings.nim
index b179bfcbc..44bb2689c 100644
--- a/tests/official/test_fixture_operations_proposer_slashings.nim
+++ b/tests/official/test_fixture_operations_proposer_slashings.nim
@@ -33,20 +33,25 @@ proc runTest(identifier: string) =
   proc `testImpl_proposer_slashing _ identifier`() =
 
     var prefix: string
-    if existsFile(testDir/"post.ssz"):
+    if existsFile(testDir/"post.ssz_snappy"):
       prefix = "[Valid]   "
     else:
       prefix = "[Invalid] "
 
     test prefix & identifier:
-      let proposerSlashing = parseTest(testDir/"proposer_slashing.ssz", SSZ, ProposerSlashing)
-      var preState = newClone(parseTest(testDir/"pre.ssz", SSZ, BeaconState))
+      let proposerSlashing = parseTest(
+        testDir/"proposer_slashing.ssz_snappy", SSZ, ProposerSlashing)
+      var
+        preState =
+          newClone(parseTest(testDir/"pre.ssz_snappy", SSZ, BeaconState))
+        cache = StateCache()
 
-      var cache = StateCache()
-
-      if existsFile(testDir/"post.ssz"):
-        let postState = newClone(parseTest(testDir/"post.ssz", SSZ, BeaconState))
-        let done = process_proposer_slashing(preState[], proposerSlashing, {}, cache).isOk
+      if existsFile(testDir/"post.ssz_snappy"):
+        let
+          postState =
+            newClone(parseTest(testDir/"post.ssz_snappy", SSZ, BeaconState))
+          done = process_proposer_slashing(
+            preState[], proposerSlashing, {}, cache).isOk
         doAssert done, "Valid proposer slashing not processed"
         check: preState[].hash_tree_root() == postState[].hash_tree_root()
         reportDiff(preState, postState)
diff --git a/tests/official/test_fixture_operations_voluntary_exit.nim b/tests/official/test_fixture_operations_voluntary_exit.nim
index 2aca7c7fe..58eb4d3d5 100644
--- a/tests/official/test_fixture_operations_voluntary_exit.nim
+++ b/tests/official/test_fixture_operations_voluntary_exit.nim
@@ -33,21 +33,25 @@ proc runTest(identifier: string) =
   proc `testImpl _ voluntary_exit _ identifier`() =
 
     var prefix: string
-    if existsFile(testDir/"post.ssz"):
+    if existsFile(testDir/"post.ssz_snappy"):
       prefix = "[Valid]   "
     else:
       prefix = "[Invalid] "
 
     test prefix & identifier:
-      let voluntaryExit = parseTest(testDir/"voluntary_exit.ssz", SSZ, SignedVoluntaryExit)
-      var preState = newClone(parseTest(testDir/"pre.ssz", SSZ, BeaconState))
+      let voluntaryExit = parseTest(
+        testDir/"voluntary_exit.ssz_snappy", SSZ, SignedVoluntaryExit)
+      var
+        preState =
+          newClone(parseTest(testDir/"pre.ssz_snappy", SSZ, BeaconState))
+        cache = StateCache()
 
-      var cache = StateCache()
-
-      if existsFile(testDir/"post.ssz"):
-        let postState = newClone(parseTest(testDir/"post.ssz", SSZ, BeaconState))
-        let done =
-          process_voluntary_exit(preState[], voluntaryExit, {}, cache).isOk
+      if existsFile(testDir/"post.ssz_snappy"):
+        let
+          postState =
+            newClone(parseTest(testDir/"post.ssz_snappy", SSZ, BeaconState))
+          done =
+            process_voluntary_exit(preState[], voluntaryExit, {}, cache).isOk
         doAssert done, "Valid voluntary exit not processed"
         check: preState[].hash_tree_root() == postState[].hash_tree_root()
         reportDiff(preState, postState)
diff --git a/tests/official/test_fixture_rewards.nim b/tests/official/test_fixture_rewards.nim
index 463fc5e37..aefd00eb2 100644
--- a/tests/official/test_fixture_rewards.nim
+++ b/tests/official/test_fixture_rewards.nim
@@ -50,16 +50,18 @@ proc runTest(rewardsDir, identifier: string) =
   proc `testImpl _ rewards _ identifier`() =
     test "Rewards" & " - " & identifier & preset():
       var
-        state = newClone(parseTest(testDir/"pre.ssz", SSZ, BeaconState))
+        state = newClone(parseTest(testDir/"pre.ssz_snappy", SSZ, BeaconState))
         cache = StateCache()
       let
-        sourceDeltas = parseTest(testDir/"source_deltas.ssz", SSZ, Deltas)
-        targetDeltas = parseTest(testDir/"target_deltas.ssz", SSZ, Deltas)
-        headDeltas = parseTest(testDir/"head_deltas.ssz", SSZ, Deltas)
+        sourceDeltas =
+          parseTest(testDir/"source_deltas.ssz_snappy", SSZ, Deltas)
+        targetDeltas =
+          parseTest(testDir/"target_deltas.ssz_snappy", SSZ, Deltas)
+        headDeltas = parseTest(testDir/"head_deltas.ssz_snappy", SSZ, Deltas)
         inclusionDelayDeltas =
-          parseTest(testDir/"inclusion_delay_deltas.ssz", SSZ, Deltas)
+          parseTest(testDir/"inclusion_delay_deltas.ssz_snappy", SSZ, Deltas)
         inactivityPenaltyDeltas =
-          parseTest(testDir/"inactivity_penalty_deltas.ssz", SSZ, Deltas)
+          parseTest(testDir/"inactivity_penalty_deltas.ssz_snappy", SSZ, Deltas)
 
       var
         rewards = RewardInfo()
diff --git a/tests/official/test_fixture_sanity_blocks.nim b/tests/official/test_fixture_sanity_blocks.nim
index f8fca1980..36dafad10 100644
--- a/tests/official/test_fixture_sanity_blocks.nim
+++ b/tests/official/test_fixture_sanity_blocks.nim
@@ -31,12 +31,12 @@ proc runTest(testName, testDir, unitTestName: string) =
 
   proc `testImpl _ blck _ testName`() =
     let
-      hasPostState = existsFile(testPath/"post.ssz")
+      hasPostState = existsFile(testPath/"post.ssz_snappy")
       prefix = if hasPostState: "[Valid]   " else: "[Invalid] "
 
     test prefix & testName & " - " & unitTestName & preset():
       var
-        preState = newClone(parseTest(testPath/"pre.ssz", SSZ, BeaconState))
+        preState = newClone(parseTest(testPath/"pre.ssz_snappy", SSZ, BeaconState))
         hashedPreState = (ref HashedBeaconState)(
           data: preState[], root: hash_tree_root(preState[]))
         cache = StateCache()
@@ -44,9 +44,9 @@ proc runTest(testName, testDir, unitTestName: string) =
 
       # In test cases with more than 10 blocks the first 10 aren't 0-prefixed,
       # so purely lexicographic sorting wouldn't sort properly.
-      let numBlocks = toSeq(walkPattern(testPath/"blocks_*.ssz")).len
+      let numBlocks = toSeq(walkPattern(testPath/"blocks_*.ssz_snappy")).len
       for i in 0 ..< numBlocks:
-        let blck = parseTest(testPath/"blocks_" & $i & ".ssz", SSZ, SignedBeaconBlock)
+        let blck = parseTest(testPath/"blocks_" & $i & ".ssz_snappy", SSZ, SignedBeaconBlock)
 
         if hasPostState:
           let success = state_transition(
@@ -61,7 +61,7 @@ proc runTest(testName, testDir, unitTestName: string) =
             "We didn't expect these invalid blocks to be processed"
 
       if hasPostState:
-        let postState = newClone(parseTest(testPath/"post.ssz", SSZ, BeaconState))
+        let postState = newClone(parseTest(testPath/"post.ssz_snappy", SSZ, BeaconState))
         when false:
           reportDiff(hashedPreState.data, postState)
         doAssert hashedPreState.root == postState[].hash_tree_root()
diff --git a/tests/official/test_fixture_sanity_slots.nim b/tests/official/test_fixture_sanity_slots.nim
index 663852ea1..f583dd61c 100644
--- a/tests/official/test_fixture_sanity_slots.nim
+++ b/tests/official/test_fixture_sanity_slots.nim
@@ -27,12 +27,12 @@ proc runTest(identifier: string) =
   proc `testImpl _ slots _ identifier`() =
     test "Slots - " & identifier:
       var
-        preState = newClone(parseTest(testDir/"pre.ssz", SSZ, BeaconState))
+        preState = newClone(parseTest(testDir/"pre.ssz_snappy", SSZ, BeaconState))
         hashedPreState = (ref HashedBeaconState)(
           data: preState[], root: hash_tree_root(preState[]))
         cache = StateCache()
         rewards: RewardInfo
-      let postState = newClone(parseTest(testDir/"post.ssz", SSZ, BeaconState))
+      let postState = newClone(parseTest(testDir/"post.ssz_snappy", SSZ, BeaconState))
 
       check:
         process_slots(
diff --git a/tests/official/test_fixture_ssz_consensus_objects.nim b/tests/official/test_fixture_ssz_consensus_objects.nim
index 9d6faf0b5..e32fd6efa 100644
--- a/tests/official/test_fixture_ssz_consensus_objects.nim
+++ b/tests/official/test_fixture_ssz_consensus_objects.nim
@@ -14,6 +14,8 @@ import
   # Beacon chain internals
   ../../beacon_chain/spec/[crypto, datatypes, digest],
   ../../beacon_chain/ssz,
+  # Status libraries
+  snappy,
   # Test utilities
   ../testutil, ./fixtures_utils
 
@@ -45,7 +47,8 @@ type
 
 proc checkSSZ(T: type SignedBeaconBlock, dir: string, expectedHash: SSZHashTreeRoot) =
   # Deserialize into a ref object to not fill Nim stack
-  let encoded = readFileBytes(dir/"serialized.ssz")
+  let encoded = snappy.decode(
+    readFileBytes(dir/"serialized.ssz_snappy"), MaxObjectSize)
   var deserialized = newClone(sszDecodeEntireInput(encoded, T))
 
   # SignedBeaconBlocks usually not hashed because they're identified by
@@ -62,7 +65,8 @@ proc checkSSZ(T: type SignedBeaconBlock, dir: string, expectedHash: SSZHashTreeR
 
 proc checkSSZ(T: type, dir: string, expectedHash: SSZHashTreeRoot) =
   # Deserialize into a ref object to not fill Nim stack
-  let encoded = readFileBytes(dir/"serialized.ssz")
+  let encoded = snappy.decode(
+    readFileBytes(dir/"serialized.ssz_snappy"), MaxObjectSize)
   var deserialized = newClone(sszDecodeEntireInput(encoded, T))
 
   check: expectedHash.root == "0x" & toLowerASCII($hash_tree_root(deserialized[]))
diff --git a/tests/official/test_fixture_ssz_generic_types.nim b/tests/official/test_fixture_ssz_generic_types.nim
index b062d1158..306774aee 100644
--- a/tests/official/test_fixture_ssz_generic_types.nim
+++ b/tests/official/test_fixture_ssz_generic_types.nim
@@ -1,5 +1,5 @@
 # beacon_chain
-# Copyright (c) 2018-2020 Status Research & Development GmbH
+# Copyright (c) 2018-2021 Status Research & Development GmbH
 # Licensed and distributed under either of
 #   * MIT license (license terms in the root directory or at https://opensource.org/licenses/MIT).
 #   * Apache v2 license (license terms in the root directory or at https://www.apache.org/licenses/LICENSE-2.0).
@@ -10,7 +10,7 @@ import
   os, strutils, streams, strformat, strscans,
   macros, typetraits,
   # Status libraries
-  faststreams, ../testutil,
+  faststreams, snappy, ../testutil,
   # Third-party
   yaml,
   # Beacon chain internals
@@ -82,7 +82,7 @@ type
 proc checkBasic(T: typedesc,
                 dir: string,
                 expectedHash: SSZHashTreeRoot) =
-  var fileContents = readFileBytes(dir/"serialized.ssz")
+  var fileContents = snappy.decode(readFileBytes(dir/"serialized.ssz_snappy"), MaxObjectSize)
   var deserialized = newClone(sszDecodeEntireInput(fileContents, T))
 
   let expectedHash = expectedHash.root
diff --git a/tests/official/test_fixture_state_transition_epoch.nim b/tests/official/test_fixture_state_transition_epoch.nim
index fbb926fdd..e5e6a2177 100644
--- a/tests/official/test_fixture_state_transition_epoch.nim
+++ b/tests/official/test_fixture_state_transition_epoch.nim
@@ -29,8 +29,8 @@ template runSuite(suiteDir, testName: string, transitionProc: untyped{ident}, us
       let unitTestName = testDir.rsplit(DirSep, 1)[1]
       test testName & " - " & unitTestName & preset():
         # BeaconState objects are stored on the heap to avoid stack overflow
-        var preState = newClone(parseTest(testDir/"pre.ssz", SSZ, BeaconState))
-        let postState = newClone(parseTest(testDir/"post.ssz", SSZ, BeaconState))
+        var preState = newClone(parseTest(testDir/"pre.ssz_snappy", SSZ, BeaconState))
+        let postState = newClone(parseTest(testDir/"post.ssz_snappy", SSZ, BeaconState))
 
         when useCache:
           var cache = StateCache()
@@ -66,5 +66,20 @@ runSuite(SlashingsDir, "Slashings",  process_slashings, useCache = false)
 # Final updates
 # ---------------------------------------------------------------
 
-const FinalUpdatesDir = SszTestsDir/const_preset/"phase0"/"epoch_processing"/"final_updates"/"pyspec_tests"
-runSuite(FinalUpdatesDir, "Final updates",  process_final_updates, useCache = false)
+const Eth1DataResetDir = SszTestsDir/const_preset/"phase0"/"epoch_processing"/"eth1_data_reset/"/"pyspec_tests"
+runSuite(Eth1DataResetDir, "Eth1 data reset", process_eth1_data_reset, useCache = false)
+
+const EffectiveBalanceUpdatesDir = SszTestsDir/const_preset/"phase0"/"epoch_processing"/"effective_balance_updates"/"pyspec_tests"
+runSuite(EffectiveBalanceUpdatesDir, "Effective balance updates", process_effective_balance_updates, useCache = false)
+
+const SlashingsResetDir = SszTestsDir/const_preset/"phase0"/"epoch_processing"/"slashings_reset"/"pyspec_tests"
+runSuite(SlashingsResetDir, "Slashings reset", process_slashings_reset, useCache = false)
+
+const RandaoMixesResetDir = SszTestsDir/const_preset/"phase0"/"epoch_processing"/"randao_mixes_reset"/"pyspec_tests"
+runSuite(RandaoMixesResetDir, "RANDAO mixes reset", process_randao_mixes_reset, useCache = false)
+
+const HistoricalRootsUpdateDir = SszTestsDir/const_preset/"phase0"/"epoch_processing"/"historical_roots_update"/"pyspec_tests"
+runSuite(HistoricalRootsUpdateDir, "Historical roots update", process_historical_roots_update, useCache = false)
+
+const ParticipationRecordsDir = SszTestsDir/const_preset/"phase0"/"epoch_processing"/"participation_record_updates"/"pyspec_tests"
+runSuite(ParticipationRecordsDir, "Participation record updates", process_participation_record_updates, useCache = false)