diff --git a/src/Nethermind/Nethermind.State/StateProvider.cs b/src/Nethermind/Nethermind.State/StateProvider.cs
index 39981c9c5a94..9121b5bb0c2a 100644
--- a/src/Nethermind/Nethermind.State/StateProvider.cs
+++ b/src/Nethermind/Nethermind.State/StateProvider.cs
@@ -547,6 +547,7 @@ public void Commit(IReleaseSpec releaseSpec, IWorldStateTracer stateTracer, bool
                 {
                     FlushToTree();
                 }
+
                 return;
             }
 
diff --git a/src/Nethermind/Nethermind.TxPool.Test/Collections/DistinctValueSortedPoolTests.cs b/src/Nethermind/Nethermind.TxPool.Test/Collections/DistinctValueSortedPoolTests.cs
index 19511d76d916..8d96891b8ba5 100644
--- a/src/Nethermind/Nethermind.TxPool.Test/Collections/DistinctValueSortedPoolTests.cs
+++ b/src/Nethermind/Nethermind.TxPool.Test/Collections/DistinctValueSortedPoolTests.cs
@@ -24,7 +24,7 @@
 namespace Nethermind.TxPool.Test.Collections
 {
     [TestFixture]
-    [Parallelizable(ParallelScope.None)]
+    [Parallelizable(ParallelScope.Self)]
     public class DistinctValueSortedPoolTests
     {
         private const int Capacity = 16;
@@ -73,13 +73,12 @@ public static IEnumerable DistinctTestCases
         [TestCaseSource(nameof(DistinctTestCases))]
         public void Distinct_transactions_are_all_added(Transaction[] transactions, int expectedCount)
         {
-
             var pool = new TxDistinctSortedPool(Capacity, _transactionComparerProvider.GetDefaultComparer(), LimboLogs.Instance);
 
-            foreach (var transaction in transactions)
+            Parallel.ForEach(transactions, transaction =>
             {
                 pool.TryInsert(transaction.Hash, transaction);
-            }
+            });
 
             pool.Count.Should().Be(expectedCount);
         }
@@ -219,14 +218,11 @@ public void Capacity_can_shrink_to_given_value(int shrinkValue, int expectedCapa
             int capacityMultiplier = 10;
             int expectedAllCount = Capacity * capacityMultiplier;
 
-            WithFinalizer newOne;
-            for (int i = 0; i < expectedAllCount; i++)
+            Parallel.For(0, expectedAllCount, i =>
             {
-                newOne = new WithFinalizer();
+                WithFinalizer newOne = new();
                 pool.TryInsert(newOne.Index, newOne);
-            }
-
-            newOne = null;
+            });
 
             CollectAndFinalize();
 
diff --git a/src/Nethermind/Nethermind.TxPool.Test/NonceManagerTests.cs b/src/Nethermind/Nethermind.TxPool.Test/NonceManagerTests.cs
index cf3add450cbc..dce8e3bde40c 100644
--- a/src/Nethermind/Nethermind.TxPool.Test/NonceManagerTests.cs
+++ b/src/Nethermind/Nethermind.TxPool.Test/NonceManagerTests.cs
@@ -191,7 +191,7 @@ public void should_reuse_nonce_if_tx_rejected()
     }
 
     [Test]
-    [Repeat(10)]
+    [Repeat(2)]
     public void should_lock_on_same_account()
     {
         using NonceLocker locker = _nonceManager.ReserveNonce(TestItem.AddressA, out UInt256 nonce);
@@ -200,7 +200,7 @@ public void should_lock_on_same_account()
         {
             using NonceLocker locker = _nonceManager.ReserveNonce(TestItem.AddressA, out UInt256 _);
         });
-        TimeSpan ts = TimeSpan.FromMilliseconds(1000);
+        TimeSpan ts = TimeSpan.FromMilliseconds(100);
         task.Wait(ts);
         task.IsCompleted.Should().Be(false);
     }
diff --git a/src/Nethermind/Nethermind.TxPool.Test/TxBroadcasterTests.cs b/src/Nethermind/Nethermind.TxPool.Test/TxBroadcasterTests.cs
index 07328103f408..82718dea4c71 100644
--- a/src/Nethermind/Nethermind.TxPool.Test/TxBroadcasterTests.cs
+++ b/src/Nethermind/Nethermind.TxPool.Test/TxBroadcasterTests.cs
@@ -76,7 +76,7 @@ public async Task should_not_broadcast_persisted_tx_to_peer_too_quickly()
         int addedTxsCount = TestItem.PrivateKeys.Length;
         Transaction[] transactions = new Transaction[addedTxsCount];
 
-        for (int i = 0; i < addedTxsCount; i++)
+        Parallel.For(0, addedTxsCount, i =>
         {
             transactions[i] = Build.A.Transaction
                 .WithGasPrice(i.GWei())
@@ -84,7 +84,7 @@ public async Task should_not_broadcast_persisted_tx_to_peer_too_quickly()
                 .TestObject;
 
             _broadcaster.Broadcast(transactions[i], true);
-        }
+        });
 
         _broadcaster.GetSnapshot().Length.Should().Be(addedTxsCount);
 
@@ -126,7 +126,7 @@ public void should_pick_best_persistent_txs_to_broadcast([Values(1, 2, 99, 100,
         int addedTxsCount = TestItem.PrivateKeys.Length;
         Transaction[] transactions = new Transaction[addedTxsCount];
 
-        for (int i = 0; i < addedTxsCount; i++)
+        Parallel.For(0, addedTxsCount, i =>
         {
             transactions[i] = Build.A.Transaction
                 .WithGasPrice(i.GWei())
@@ -134,7 +134,7 @@ public void should_pick_best_persistent_txs_to_broadcast([Values(1, 2, 99, 100,
                 .TestObject;
 
             _broadcaster.Broadcast(transactions[i], true);
-        }
+        });
 
         _broadcaster.GetSnapshot().Length.Should().Be(addedTxsCount);
 
@@ -210,7 +210,7 @@ public void should_skip_large_txs_when_picking_best_persistent_txs_to_broadcast(
         int addedTxsCount = TestItem.PrivateKeys.Length;
         Transaction[] transactions = new Transaction[addedTxsCount];
 
-        for (int i = 0; i < addedTxsCount; i++)
+        Parallel.For(0, addedTxsCount, i =>
         {
             bool isLarge = i % 10 == 0;
             transactions[i] = Build.A.Transaction
@@ -221,7 +221,7 @@ public void should_skip_large_txs_when_picking_best_persistent_txs_to_broadcast(
                 .TestObject;
 
             _broadcaster.Broadcast(transactions[i], true);
-        }
+        });
 
         _broadcaster.GetSnapshot().Length.Should().Be(addedTxsCount);
 
@@ -256,7 +256,7 @@ public void should_skip_blob_txs_when_picking_best_persistent_txs_to_broadcast([
         int addedTxsCount = TestItem.PrivateKeys.Length;
         Transaction[] transactions = new Transaction[addedTxsCount];
 
-        for (int i = 0; i < addedTxsCount; i++)
+        Parallel.For(0, addedTxsCount, i =>
         {
             bool isBlob = i % 10 == 0;
             transactions[i] = Build.A.Transaction
@@ -267,7 +267,7 @@ public void should_skip_blob_txs_when_picking_best_persistent_txs_to_broadcast([
                 .TestObject;
 
             _broadcaster.Broadcast(transactions[i], true);
-        }
+        });
 
         _broadcaster.GetSnapshot().Length.Should().Be(addedTxsCount);
 
@@ -308,7 +308,7 @@ public void should_not_pick_txs_with_GasPrice_lower_than_CurrentBaseFee([Values(
         int addedTxsCount = TestItem.PrivateKeys.Length;
         Transaction[] transactions = new Transaction[addedTxsCount];
 
-        for (int i = 0; i < addedTxsCount; i++)
+        Parallel.For(0, addedTxsCount, i =>
         {
             transactions[i] = Build.A.Transaction
                 .WithGasPrice(i.GWei())
@@ -316,7 +316,7 @@ public void should_not_pick_txs_with_GasPrice_lower_than_CurrentBaseFee([Values(
                 .TestObject;
 
             _broadcaster.Broadcast(transactions[i], true);
-        }
+        });
 
         _broadcaster.GetSnapshot().Length.Should().Be(addedTxsCount);
 
@@ -382,7 +382,7 @@ public void should_not_pick_1559_txs_with_MaxFeePerGas_lower_than_CurrentBaseFee
         int addedTxsCount = TestItem.PrivateKeys.Length;
         Transaction[] transactions = new Transaction[addedTxsCount];
 
-        for (int i = 0; i < addedTxsCount; i++)
+        Parallel.For(0, addedTxsCount, i =>
         {
             transactions[i] = Build.A.Transaction
                 .WithType(TxType.EIP1559)
@@ -391,7 +391,7 @@ public void should_not_pick_1559_txs_with_MaxFeePerGas_lower_than_CurrentBaseFee
                 .TestObject;
 
             _broadcaster.Broadcast(transactions[i], true);
-        }
+        });
 
         _broadcaster.GetSnapshot().Length.Should().Be(addedTxsCount);
 
@@ -423,14 +423,17 @@ public void should_not_pick_blob_txs_with_MaxFeePerBlobGas_lower_than_CurrentFee
         int addedTxsCount = TestItem.PrivateKeys.Length;
         Transaction[] transactions = new Transaction[addedTxsCount];
 
-        for (int i = 0; i < addedTxsCount; i++)
+        Parallel.For(0, addedTxsCount, i =>
         {
             transactions[i] = Build.A.Transaction
                 .WithShardBlobTxTypeAndFields()
                 .WithMaxFeePerBlobGas(i.GWei())
                 .SignedAndResolved(_ethereumEcdsa, TestItem.PrivateKeys[i])
                 .TestObject;
+        });
 
+        for (int i = 0; i < addedTxsCount; i++)
+        {
             _broadcaster.Broadcast(transactions[i], true);
         }
 
@@ -466,7 +469,7 @@ public void should_pick_tx_with_lowest_nonce_from_bucket()
         const int addedTxsCount = 5;
         Transaction[] transactions = new Transaction[addedTxsCount];
 
-        for (int i = 0; i < addedTxsCount; i++)
+        Parallel.For(0, addedTxsCount, i =>
         {
             transactions[i] = Build.A.Transaction
                 .WithNonce((UInt256)i)
@@ -475,7 +478,7 @@ public void should_pick_tx_with_lowest_nonce_from_bucket()
                 .TestObject;
 
             _broadcaster.Broadcast(transactions[i], true);
-        }
+        });
         _broadcaster.GetSnapshot().Length.Should().Be(addedTxsCount);
 
         IList<Transaction> pickedTxs = _broadcaster.GetPersistentTxsToSend().TransactionsToSend;
@@ -676,13 +679,13 @@ public void should_rebroadcast_all_persistent_transactions_if_PeerNotificationTh
         _txPoolConfig = new TxPoolConfig() { Size = 100, PeerNotificationThreshold = shouldBroadcastAll ? 100 : 5 };
         _broadcaster = new TxBroadcaster(_comparer, TimerFactory.Default, _txPoolConfig, _headInfo, _logManager);
 
-        for (int i = 0; i < _txPoolConfig.Size; i++)
+        Parallel.For(0, _txPoolConfig.Size, i =>
         {
             Transaction tx = Build.A.Transaction
                 .WithNonce((UInt256)i)
                 .SignedAndResolved(TestItem.PrivateKeyA).TestObject;
             _broadcaster.Broadcast(tx, true);
-        }
+        });
 
         Transaction[] pickedTxs = _broadcaster.GetPersistentTxsToSend().TransactionsToSend.ToArray();
         pickedTxs.Length.Should().Be(shouldBroadcastAll ? 100 : 1);
diff --git a/src/Nethermind/Nethermind.TxPool.Test/TxPoolTests.Blobs.cs b/src/Nethermind/Nethermind.TxPool.Test/TxPoolTests.Blobs.cs
index ea37e41afa26..5d1e4ff7aaaf 100644
--- a/src/Nethermind/Nethermind.TxPool.Test/TxPoolTests.Blobs.cs
+++ b/src/Nethermind/Nethermind.TxPool.Test/TxPoolTests.Blobs.cs
@@ -132,17 +132,22 @@ public void should_reject_txs_with_nonce_too_far_in_future(TxType txType, int ma
             };
             _txPool = CreatePool(txPoolConfig, GetCancunSpecProvider());
             EnsureSenderBalance(TestItem.AddressA, UInt256.MaxValue);
-            for (int nonce = 0; nonce < txPoolConfig.Size; nonce++)
+
+            Transaction[] txs = new Transaction[txPoolConfig.Size];
+            Parallel.For(0, txPoolConfig.Size, (nonce) =>
             {
-                Transaction tx = Build.A.Transaction
+                txs[nonce] = Build.A.Transaction
                     .WithNonce((UInt256)nonce)
                     .WithType(txType)
                     .WithShardBlobTxTypeAndFieldsIfBlobTx()
                     .WithMaxFeePerGas(1.GWei())
                     .WithMaxPriorityFeePerGas(1.GWei())
                     .SignedAndResolved(_ethereumEcdsa, TestItem.PrivateKeyA).TestObject;
+            });
 
-                _txPool.SubmitTx(tx, TxHandlingOptions.None).Should().Be(nonce > expectedNumberOfAcceptedTxs
+            for (int nonce = 0; nonce < txPoolConfig.Size; nonce++)
+            {
+                _txPool.SubmitTx(txs[nonce], TxHandlingOptions.None).Should().Be(nonce > expectedNumberOfAcceptedTxs
                     ? AcceptTxResult.NonceTooFarInFuture
                     : AcceptTxResult.Accepted);
             }
@@ -775,7 +780,8 @@ public void should_index_blobs_when_adding_txs([Values(true, false)] bool isPers
         public void should_handle_indexing_blobs_when_adding_txs_in_parallel([Values(true, false)] bool isPersistentStorage)
         {
             const int txsPerSender = 10;
-            int poolSize = TestItem.PrivateKeys.Length * txsPerSender;
+            PrivateKey[] testPrivateKeys = TestItem.PrivateKeys[..64];
+            int poolSize = testPrivateKeys.Length * txsPerSender;
             TxPoolConfig txPoolConfig = new()
             {
                 BlobsSupport = isPersistentStorage ? BlobsSupportMode.Storage : BlobsSupportMode.InMemory,
@@ -791,13 +797,13 @@ public void should_handle_indexing_blobs_when_adding_txs_in_parallel([Values(tru
 
             byte[] expectedBlobVersionedHash = null;
 
-            foreach (PrivateKey privateKey in TestItem.PrivateKeys)
+            foreach (PrivateKey privateKey in testPrivateKeys)
             {
                 EnsureSenderBalance(privateKey.Address, UInt256.MaxValue);
             }
 
             // adding, getting and removing txs in parallel
-            Parallel.ForEach(TestItem.PrivateKeys, privateKey =>
+            Parallel.ForEach(testPrivateKeys, privateKey =>
             {
                 for (int i = 0; i < txsPerSender; i++)
                 {
diff --git a/src/Nethermind/Nethermind.TxPool.Test/TxPoolTests.cs b/src/Nethermind/Nethermind.TxPool.Test/TxPoolTests.cs
index 0e6e00b4c795..823d402adea2 100644
--- a/src/Nethermind/Nethermind.TxPool.Test/TxPoolTests.cs
+++ b/src/Nethermind/Nethermind.TxPool.Test/TxPoolTests.cs
@@ -15,6 +15,7 @@
 using Nethermind.Consensus.Transactions;
 using Nethermind.Consensus.Validators;
 using Nethermind.Core;
+using Nethermind.Core.Collections;
 using Nethermind.Core.Crypto;
 using Nethermind.Core.Events;
 using Nethermind.Core.Extensions;
@@ -563,7 +564,7 @@ public void should_not_add_tx_if_already_pending_lower_nonces_are_exhausting_bal
 
             EnsureSenderBalance(TestItem.AddressA, (UInt256)(oneTxPrice * numberOfTxsPossibleToExecuteBeforeGasExhaustion));
 
-            for (int i = 0; i < 10; i++)
+            Parallel.For(0, 10, i =>
             {
                 transactions[i] = Build.A.Transaction
                     .WithSenderAddress(TestItem.AddressA)
@@ -572,6 +573,10 @@ public void should_not_add_tx_if_already_pending_lower_nonces_are_exhausting_bal
                     .WithGasLimit(_txGasLimit)
                     .WithValue(value)
                     .SignedAndResolved(_ethereumEcdsa, TestItem.PrivateKeyA).TestObject;
+            });
+
+            for (int i = 0; i < 10; i++)
+            {
                 _txPool.SubmitTx(transactions[i], TxHandlingOptions.PersistentBroadcast);
             }
 
@@ -591,16 +596,22 @@ public void should_not_count_txs_with_stale_nonces_when_calculating_cumulative_c
 
             EnsureSenderBalance(TestItem.AddressA, (UInt256)(oneTxPrice * numberOfTxsPossibleToExecuteBeforeGasExhaustion));
 
-            for (int i = 0; i < numberOfTxsPossibleToExecuteBeforeGasExhaustion * 2; i++)
+            int count = numberOfTxsPossibleToExecuteBeforeGasExhaustion * 2;
+            using ArrayPoolList<Transaction> transactions = new(count, count);
+            Parallel.For(0, count, i =>
             {
-                Transaction tx = Build.A.Transaction
+                transactions[i] = Build.A.Transaction
                     .WithSenderAddress(TestItem.AddressA)
                     .WithNonce((UInt256)i)
                     .WithGasPrice((UInt256)gasPrice)
                     .WithGasLimit(_txGasLimit)
                     .WithValue(value)
                     .SignedAndResolved(_ethereumEcdsa, TestItem.PrivateKeyA).TestObject;
-                _txPool.SubmitTx(tx, TxHandlingOptions.PersistentBroadcast);
+            });
+
+            for (int i = 0; i < count; i++)
+            {
+                _txPool.SubmitTx(transactions[i], TxHandlingOptions.PersistentBroadcast);
 
                 if (i < numberOfStaleTxsInBucket)
                 {
@@ -617,15 +628,16 @@ public void should_not_count_txs_with_stale_nonces_when_calculating_cumulative_c
         [Test]
         public void should_add_tx_if_cost_of_executing_all_txs_in_bucket_exceeds_balance_but_these_with_lower_nonces_doesnt()
         {
+            const int count = 10;
             const int gasPrice = 10;
             const int value = 1;
             int oneTxPrice = _txGasLimit * gasPrice + value;
             _txPool = CreatePool();
-            Transaction[] transactions = new Transaction[10];
+            Transaction[] transactions = new Transaction[count];
 
             EnsureSenderBalance(TestItem.AddressA, (UInt256)(oneTxPrice * 8));
 
-            for (int i = 0; i < 10; i++)
+            Parallel.For(0, count, i =>
             {
                 transactions[i] = Build.A.Transaction
                     .WithSenderAddress(TestItem.AddressA)
@@ -634,6 +646,10 @@ public void should_add_tx_if_cost_of_executing_all_txs_in_bucket_exceeds_balance
                     .WithGasLimit(_txGasLimit)
                     .WithValue(value)
                     .SignedAndResolved(_ethereumEcdsa, TestItem.PrivateKeyA).TestObject;
+            });
+
+            for (int i = 0; i < count; i++)
+            {
                 if (i != 7)
                 {
                     _txPool.SubmitTx(transactions[i], TxHandlingOptions.PersistentBroadcast);
@@ -662,7 +678,7 @@ public void should_discard_tx_because_of_overflow_of_cumulative_cost_of_this_tx_
 
             UInt256.MaxValue.Divide(GasCostOf.Transaction * 2, out UInt256 halfOfMaxGasPriceWithoutOverflow);
 
-            for (int i = 0; i < 3; i++)
+            Parallel.For(0, 3, i =>
             {
                 transactions[i] = Build.A.Transaction
                     .WithSenderAddress(TestItem.AddressA)
@@ -670,11 +686,10 @@ public void should_discard_tx_because_of_overflow_of_cumulative_cost_of_this_tx_
                     .WithGasPrice(halfOfMaxGasPriceWithoutOverflow)
                     .WithGasLimit(GasCostOf.Transaction)
                     .SignedAndResolved(_ethereumEcdsa, TestItem.PrivateKeyA).TestObject;
-                if (i != 2)
-                {
-                    _txPool.SubmitTx(transactions[i], TxHandlingOptions.PersistentBroadcast);
-                }
-            }
+            });
+
+            _txPool.SubmitTx(transactions[0], TxHandlingOptions.PersistentBroadcast);
+            _txPool.SubmitTx(transactions[1], TxHandlingOptions.PersistentBroadcast);
 
             transactions[2].GasPrice = 5;
             _txPool.GetPendingTransactionsCount().Should().Be(2);
@@ -689,7 +704,7 @@ public async Task should_not_dump_GasBottleneck_of_all_txs_in_bucket_if_first_tx
 
             EnsureSenderBalance(TestItem.AddressA, UInt256.MaxValue);
 
-            for (int i = 0; i < 5; i++)
+            Parallel.For(0, 5, i =>
             {
                 transactions[i] = Build.A.Transaction
                     .WithSenderAddress(TestItem.AddressA)
@@ -697,7 +712,7 @@ public async Task should_not_dump_GasBottleneck_of_all_txs_in_bucket_if_first_tx
                     .WithGasPrice((UInt256)(i + 2))
                     .SignedAndResolved(_ethereumEcdsa, TestItem.PrivateKeyA).TestObject;
                 _txPool.SubmitTx(transactions[i], TxHandlingOptions.PersistentBroadcast);
-            }
+            });
 
             for (int i = 0; i < 3; i++)
             {
@@ -720,7 +735,7 @@ public async Task should_not_fail_if_there_is_no_current_nonce_in_bucket()
 
             EnsureSenderBalance(TestItem.AddressA, UInt256.MaxValue);
 
-            for (int i = 0; i < 3; i++)
+            Parallel.For(0, 3, i =>
             {
                 transactions[i] = Build.A.Transaction
                     .WithSenderAddress(TestItem.AddressA)
@@ -728,7 +743,7 @@ public async Task should_not_fail_if_there_is_no_current_nonce_in_bucket()
                     .WithGasPrice((UInt256)(i + 2))
                     .SignedAndResolved(_ethereumEcdsa, TestItem.PrivateKeyA).TestObject;
                 _txPool.SubmitTx(transactions[i], TxHandlingOptions.PersistentBroadcast);
-            }
+            });
 
             for (int i = 0; i < 3; i++)
             {
@@ -775,13 +790,17 @@ public void should_calculate_gasBottleneck_properly()
             _txPool = CreatePool();
             Transaction[] transactions = new Transaction[5];
 
-            for (int i = 0; i < 5; i++)
+            Parallel.For(0, 5, i =>
             {
                 transactions[i] = Build.A.Transaction
                     .WithSenderAddress(TestItem.AddressA)
                     .WithNonce((UInt256)i)
                     .WithGasPrice((UInt256)(i + 2))
                     .SignedAndResolved(_ethereumEcdsa, TestItem.PrivateKeyA).TestObject;
+            });
+
+            for (int i = 0; i < 5; i++)
+            {
                 EnsureSenderBalance(transactions[i]);
                 _txPool.SubmitTx(transactions[i], TxHandlingOptions.PersistentBroadcast);
             }
@@ -797,7 +816,7 @@ public async Task should_remove_txs_with_old_nonces_when_updating_GasBottleneck(
             Transaction[] transactions = new Transaction[5];
             EnsureSenderBalance(TestItem.AddressA, UInt256.MaxValue);
 
-            for (int i = 0; i < 5; i++)
+            Parallel.For(0, 5, i =>
             {
                 transactions[i] = Build.A.Transaction
                     .WithSenderAddress(TestItem.AddressA)
@@ -805,7 +824,7 @@ public async Task should_remove_txs_with_old_nonces_when_updating_GasBottleneck(
                     .WithGasPrice((UInt256)(i + 2))
                     .SignedAndResolved(_ethereumEcdsa, TestItem.PrivateKeyA).TestObject;
                 _txPool.SubmitTx(transactions[i], TxHandlingOptions.PersistentBroadcast);
-            }
+            });
             _txPool.GetPendingTransactionsCount().Should().Be(5);
 
             for (int i = 0; i < 3; i++)
@@ -853,7 +872,7 @@ public void should_remove_stale_txs_from_persistent_transactions(int numberOfTxs
             Transaction[] transactions = new Transaction[numberOfTxs];
             EnsureSenderBalance(TestItem.AddressA, UInt256.MaxValue);
 
-            for (int i = 0; i < numberOfTxs; i++)
+            Parallel.For(0, numberOfTxs, i =>
             {
                 transactions[i] = Build.A.Transaction
                     .WithNonce((UInt256)i)
@@ -862,7 +881,7 @@ public void should_remove_stale_txs_from_persistent_transactions(int numberOfTxs
                     .SignedAndResolved(_ethereumEcdsa, TestItem.PrivateKeyA)
                     .TestObject;
                 _txPool.SubmitTx(transactions[i], TxHandlingOptions.PersistentBroadcast);
-            }
+            });
             _txPool.GetOwnPendingTransactions().Length.Should().Be(numberOfTxs);
 
             Block block = Build.A.Block.WithTransactions(transactions[nonceIncludedInBlock]).TestObject;
@@ -1554,16 +1573,21 @@ public void Should_not_replace_better_txs_by_worse_ones()
             TxPoolConfig txPoolConfig = new TxPoolConfig { Size = 128 };
             _txPool = CreatePool(txPoolConfig);
 
+            using ArrayPoolList<Transaction> transactions = new(txPoolConfig.Size, txPoolConfig.Size);
             // send (size - 1) standard txs from different senders
-            for (int i = 0; i < txPoolConfig.Size - 1; i++)
+            Parallel.For(0, txPoolConfig.Size, i =>
             {
-                Transaction tx = Build.A.Transaction
+                transactions[i] = Build.A.Transaction
                     .WithNonce(0)
                     .WithValue(0)
                     .WithGasPrice(10)
                     .WithTo(TestItem.AddressB)
                     .SignedAndResolved(_ethereumEcdsa, TestItem.PrivateKeys[i]).TestObject;
+            });
 
+            for (int i = 0; i < txPoolConfig.Size - 1; i++)
+            {
+                Transaction tx = transactions[i];
                 EnsureSenderBalance(TestItem.PrivateKeys[i].Address, UInt256.MaxValue);
                 AcceptTxResult result = _txPool.SubmitTx(tx, TxHandlingOptions.PersistentBroadcast);
 
@@ -1589,15 +1613,22 @@ public void Should_not_replace_better_txs_by_worse_ones()
             _txPool.GetPendingTransactionsCount().Should().Be(txPoolConfig.Size);
             _txPool.GetPendingTransactionsBySender().Keys.Count.Should().Be(txPoolConfig.Size);
 
-            // send (size - 1) expensive txs from sender X
-            for (int i = 0; i < txPoolConfig.Size - 1; i++)
+            using ArrayPoolList<Transaction> txs = new(txPoolConfig.Size, txPoolConfig.Size);
+            // send (size - 1) standard txs from different senders
+            Parallel.For(0, txPoolConfig.Size, i =>
             {
-                Transaction tx = Build.A.Transaction
+                txs[i] = Build.A.Transaction
                     .WithNonce((UInt256)(i + 1))
                     .WithValue(0)
                     .WithGasPrice(1000)
                     .WithTo(TestItem.AddressB)
                     .SignedAndResolved(_ethereumEcdsa, privateKeyOfAttacker).TestObject;
+            });
+
+            // send (size - 1) expensive txs from sender X
+            for (int i = 0; i < txPoolConfig.Size - 1; i++)
+            {
+                Transaction tx = txs[i];
 
                 AcceptTxResult result = _txPool.SubmitTx(tx, TxHandlingOptions.PersistentBroadcast);
                 result.Should().Be(AcceptTxResult.FeeTooLowToCompete);
@@ -1615,13 +1646,20 @@ public void Should_not_replace_ready_txs_by_nonce_gap_ones()
             TxPoolConfig txPoolConfig = new() { Size = 128 };
             _txPool = CreatePool(txPoolConfig);
 
+            using ArrayPoolList<Transaction> txs = new(txPoolConfig.Size, txPoolConfig.Size);
             // send (size - 1) standard txs from different senders
-            for (int i = 0; i < txPoolConfig.Size - 1; i++)
+            Parallel.For(0, txPoolConfig.Size, i =>
             {
-                Transaction tx = Build.A.Transaction
+                txs[i] = Build.A.Transaction
                     .WithNonce(0)
                     .WithGasPrice(10)
                     .SignedAndResolved(_ethereumEcdsa, TestItem.PrivateKeys[i]).TestObject;
+            });
+
+            // send (size - 1) standard txs from different senders
+            for (int i = 0; i < txPoolConfig.Size - 1; i++)
+            {
+                Transaction tx = txs[i];
 
                 EnsureSenderBalance(TestItem.PrivateKeys[i].Address, UInt256.MaxValue);
                 _txPool.SubmitTx(tx, TxHandlingOptions.PersistentBroadcast).Should().Be(AcceptTxResult.Accepted);
@@ -1644,14 +1682,18 @@ public void Should_not_replace_ready_txs_by_nonce_gap_ones()
             _txPool.GetPendingTransactionsCount().Should().Be(txPoolConfig.Size);
             _txPool.GetPendingTransactionsBySender().Keys.Count.Should().Be(txPoolConfig.Size);
 
-            // send (size - 1) expensive txs from sender X with consecutive nonces
-            for (int i = 0; i < txPoolConfig.Size - 1; i++)
+            using ArrayPoolList<Transaction> txs2 = new(txPoolConfig.Size, txPoolConfig.Size);
+            Parallel.For(0, txPoolConfig.Size, i =>
             {
-                Transaction tx = Build.A.Transaction
+                txs2[i] = Build.A.Transaction
                     .WithNonce((UInt256)(i + 1 + nonceGap))
                     .WithGasPrice(1000)
                     .SignedAndResolved(_ethereumEcdsa, privateKeyOfAttacker).TestObject;
-
+            });
+            // send (size - 1) expensive txs from sender X with consecutive nonces
+            for (int i = 0; i < txPoolConfig.Size - 1; i++)
+            {
+                Transaction tx = txs2[i];
                 _txPool.SubmitTx(tx, TxHandlingOptions.PersistentBroadcast).Should().Be(AcceptTxResult.FeeTooLowToCompete);
 
                 // newly coming txs should evict themselves
@@ -1668,16 +1710,21 @@ public void Should_not_add_underpaid_tx_even_if_lower_nonces_are_expensive(int g
             TxPoolConfig txPoolConfig = new TxPoolConfig { Size = 128 };
             _txPool = CreatePool(txPoolConfig);
 
-            // send standard txs from different senders
-            for (int i = 1; i < txPoolConfig.Size; i++)
+            using ArrayPoolList<Transaction> txs = new(txPoolConfig.Size, txPoolConfig.Size);
+            Parallel.For(1, txPoolConfig.Size, i =>
             {
-                Transaction tx = Build.A.Transaction
+                txs[i] = Build.A.Transaction
                     .WithNonce(0)
                     .WithValue(0)
                     .WithGasPrice(10)
                     .WithTo(TestItem.AddressB)
                     .SignedAndResolved(_ethereumEcdsa, TestItem.PrivateKeys[i]).TestObject;
+            });
 
+            // send standard txs from different senders
+            for (int i = 1; i < txPoolConfig.Size; i++)
+            {
+                Transaction tx = txs[i];
                 EnsureSenderBalance(TestItem.PrivateKeys[i].Address, UInt256.MaxValue);
                 _txPool.SubmitTx(tx, TxHandlingOptions.PersistentBroadcast).Should().Be(AcceptTxResult.Accepted);
             }
@@ -2083,13 +2130,13 @@ public void SetCode_tx_can_be_replaced_and_remove_pending_delegation_restriction
             result.Should().Be(AcceptTxResult.Accepted);
 
             Transaction thirdTx = Build.A.Transaction
-            .WithNonce(1)
-            .WithType(TxType.EIP1559)
-            .WithMaxFeePerGas(9.GWei())
-            .WithMaxPriorityFeePerGas(9.GWei())
-            .WithGasLimit(GasCostOf.Transaction)
-            .WithTo(TestItem.AddressB)
-            .SignedAndResolved(_ethereumEcdsa, signer).TestObject;
+                .WithNonce(1)
+                .WithType(TxType.EIP1559)
+                .WithMaxFeePerGas(9.GWei())
+                .WithMaxPriorityFeePerGas(9.GWei())
+                .WithGasLimit(GasCostOf.Transaction)
+                .WithTo(TestItem.AddressB)
+                .SignedAndResolved(_ethereumEcdsa, signer).TestObject;
 
             result = _txPool.SubmitTx(thirdTx, TxHandlingOptions.PersistentBroadcast);