diff --git a/common/math/integer.go b/common/math/integer.go
index 93b1d036d..46d91ab2a 100644
--- a/common/math/integer.go
+++ b/common/math/integer.go
@@ -18,6 +18,7 @@ package math
 
 import (
 	"fmt"
+	"math/bits"
 	"strconv"
 )
 
@@ -87,13 +88,12 @@ func SafeSub(x, y uint64) (uint64, bool) {
 
 // SafeAdd returns the result and whether overflow occurred.
 func SafeAdd(x, y uint64) (uint64, bool) {
-	return x + y, y > MaxUint64-x
+	sum, carry := bits.Add64(x, y, 0)
+	return sum, carry != 0
 }
 
 // SafeMul returns multiplication result and whether overflow occurred.
 func SafeMul(x, y uint64) (uint64, bool) {
-	if x == 0 || y == 0 {
-		return 0, false
-	}
-	return x * y, y > MaxUint64/x
+	hi, lo := bits.Mul64(x, y)
+	return lo, hi != 0
 }
diff --git a/core/tx_list.go b/core/tx_list.go
index 164c73006..8beb28bba 100644
--- a/core/tx_list.go
+++ b/core/tx_list.go
@@ -99,7 +99,30 @@ func (m *txSortedMap) Forward(threshold uint64) types.Transactions {
 
 // Filter iterates over the list of transactions and removes all of them for which
 // the specified function evaluates to true.
+// Filter, as opposed to 'filter', re-initialises the heap after the operation is done.
+// If you want to do several consecutive filterings, it's therefore better to first
+// do a .filter(func1) followed by .Filter(func2) or reheap()
 func (m *txSortedMap) Filter(filter func(*types.Transaction) bool) types.Transactions {
+	removed := m.filter(filter)
+	// If transactions were removed, the heap and cache are ruined
+	if len(removed) > 0 {
+		m.reheap()
+	}
+	return removed
+}
+
+func (m *txSortedMap) reheap() {
+	*m.index = make([]uint64, 0, len(m.items))
+	for nonce := range m.items {
+		*m.index = append(*m.index, nonce)
+	}
+	heap.Init(m.index)
+	m.cache = nil
+}
+
+// filter is identical to Filter, but **does not** regenerate the heap. This method
+// should only be used if followed immediately by a call to Filter or reheap()
+func (m *txSortedMap) filter(filter func(*types.Transaction) bool) types.Transactions {
 	var removed types.Transactions
 
 	// Collect all the transactions to filter out
@@ -109,14 +132,7 @@ func (m *txSortedMap) Filter(filter func(*types.Transaction) bool) types.Transac
 			delete(m.items, nonce)
 		}
 	}
-	// If transactions were removed, the heap and cache are ruined
 	if len(removed) > 0 {
-		*m.index = make([]uint64, 0, len(m.items))
-		for nonce := range m.items {
-			*m.index = append(*m.index, nonce)
-		}
-		heap.Init(m.index)
-
 		m.cache = nil
 	}
 	return removed
@@ -197,10 +213,7 @@ func (m *txSortedMap) Len() int {
 	return len(m.items)
 }
 
-// Flatten creates a nonce-sorted slice of transactions based on the loosely
-// sorted internal representation. The result of the sorting is cached in case
-// it's requested again before any modifications are made to the contents.
-func (m *txSortedMap) Flatten() types.Transactions {
+func (m *txSortedMap) flatten() types.Transactions {
 	// If the sorting was not cached yet, create and cache it
 	if m.cache == nil {
 		m.cache = make(types.Transactions, 0, len(m.items))
@@ -209,12 +222,27 @@ func (m *txSortedMap) Flatten() types.Transactions {
 		}
 		sort.Sort(types.TxByNonce(m.cache))
 	}
+	return m.cache
+}
+
+// Flatten creates a nonce-sorted slice of transactions based on the loosely
+// sorted internal representation. The result of the sorting is cached in case
+// it's requested again before any modifications are made to the contents.
+func (m *txSortedMap) Flatten() types.Transactions {
 	// Copy the cache to prevent accidental modifications
-	txs := make(types.Transactions, len(m.cache))
-	copy(txs, m.cache)
+	cache := m.flatten()
+	txs := make(types.Transactions, len(cache))
+	copy(txs, cache)
 	return txs
 }
 
+// LastElement returns the last element of a flattened list, thus, the
+// transaction with the highest nonce
+func (m *txSortedMap) LastElement() *types.Transaction {
+	cache := m.flatten()
+	return cache[len(cache)-1]
+}
+
 // txList is a "list" of transactions belonging to an account, sorted by account
 // nonce. The same type can be used both for storing contiguous transactions for
 // the executable/pending queue; and for storing gapped transactions for the non-
@@ -223,17 +251,16 @@ type txList struct {
 	strict bool         // Whether nonces are strictly continuous or not
 	txs    *txSortedMap // Heap indexed sorted hash map of the transactions
 
-	costcap *big.Int // Price of the highest costing transaction (reset only if exceeds balance)
-	gascap  uint64   // Gas limit of the highest spending transaction (reset only if exceeds block limit)
+	costcap uint64 // Price of the highest costing transaction (reset only if exceeds balance)
+	gascap  uint64 // Gas limit of the highest spending transaction (reset only if exceeds block limit)
 }
 
 // newTxList create a new transaction list for maintaining nonce-indexable fast,
 // gapped, sortable transaction lists.
 func newTxList(strict bool) *txList {
 	return &txList{
-		strict:  strict,
-		txs:     newTxSortedMap(),
-		costcap: new(big.Int),
+		strict: strict,
+		txs:    newTxSortedMap(),
 	}
 }
 
@@ -252,7 +279,11 @@ func (l *txList) Add(tx *types.Transaction, priceBump uint64) (bool, *types.Tran
 	// If there's an older better transaction, abort
 	old := l.txs.Get(tx.Nonce())
 	if old != nil {
-		threshold := new(big.Int).Div(new(big.Int).Mul(old.GasPrice(), big.NewInt(100+int64(priceBump))), big.NewInt(100))
+		// threshold = oldGP * (100 + priceBump) / 100
+		a := big.NewInt(100 + int64(priceBump))
+		a = a.Mul(a, old.GasPrice())
+		b := big.NewInt(100)
+		threshold := a.Div(a, b)
 		// Have to ensure that the new gas price is higher than the old gas
 		// price as well as checking the percentage threshold to ensure that
 		// this is accurate for low (Wei-level) gas price replacements
@@ -260,9 +291,14 @@ func (l *txList) Add(tx *types.Transaction, priceBump uint64) (bool, *types.Tran
 			return false, nil
 		}
 	}
+	cost, overflow := tx.CostU64()
+	if overflow {
+		log.Warn("transaction cost overflown, txHash: %v txCost: %v", tx.Hash(), cost)
+		return false, nil
+	}
 	// Otherwise overwrite the old transaction with the current one
 	l.txs.Put(tx)
-	if cost := tx.Cost(); l.costcap.Cmp(cost) < 0 {
+	if l.costcap < cost {
 		l.costcap = cost
 	}
 	if gas := tx.Gas(); l.gascap < gas {
@@ -287,29 +323,35 @@ func (l *txList) Forward(threshold uint64) types.Transactions {
 // a point in calculating all the costs or if the balance covers all. If the threshold
 // is lower than the costgas cap, the caps will be reset to a new high after removing
 // the newly invalidated transactions.
-func (l *txList) Filter(costLimit *big.Int, gasLimit uint64) (types.Transactions, types.Transactions) {
+func (l *txList) Filter(costLimit uint64, gasLimit uint64) (types.Transactions, types.Transactions) {
 	// If all transactions are below the threshold, short circuit
-	if l.costcap.Cmp(costLimit) <= 0 && l.gascap <= gasLimit {
+	if l.costcap <= costLimit && l.gascap <= gasLimit {
 		return nil, nil
 	}
-	l.costcap = new(big.Int).Set(costLimit) // Lower the caps to the thresholds
+	l.costcap = costLimit // Lower the caps to the thresholds
 	l.gascap = gasLimit
 
 	// Filter out all the transactions above the account's funds
-	removed := l.txs.Filter(func(tx *types.Transaction) bool { return tx.Cost().Cmp(costLimit) > 0 || tx.Gas() > gasLimit })
+	removed := l.txs.filter(func(tx *types.Transaction) bool {
+		cost, _ := tx.CostU64()
+		return cost > costLimit || tx.Gas() > gasLimit
+	})
 
-	// If the list was strict, filter anything above the lowest nonce
+	if len(removed) == 0 {
+		return nil, nil
+	}
 	var invalids types.Transactions
-
-	if l.strict && len(removed) > 0 {
+	// If the list was strict, filter anything above the lowest nonce
+	if l.strict {
 		lowest := uint64(math.MaxUint64)
 		for _, tx := range removed {
 			if nonce := tx.Nonce(); lowest > nonce {
 				lowest = nonce
 			}
 		}
-		invalids = l.txs.Filter(func(tx *types.Transaction) bool { return tx.Nonce() > lowest })
+		invalids = l.txs.filter(func(tx *types.Transaction) bool { return tx.Nonce() > lowest })
 	}
+	l.txs.reheap()
 	return removed, invalids
 }
 
@@ -363,6 +405,12 @@ func (l *txList) Flatten() types.Transactions {
 	return l.txs.Flatten()
 }
 
+// LastElement returns the last element of a flattened list, thus, the
+// transaction with the highest nonce
+func (l *txList) LastElement() *types.Transaction {
+	return l.txs.LastElement()
+}
+
 // priceHeap is a heap.Interface implementation over transactions for retrieving
 // price-sorted transactions to discard when the pool fills up.
 type priceHeap []*types.Transaction
@@ -495,8 +543,29 @@ func (l *txPricedList) Underpriced(tx *types.Transaction, local *accountSet) boo
 // Discard finds a number of most underpriced transactions, removes them from the
 // priced list and returns them for further removal from the entire pool.
 func (l *txPricedList) Discard(slots int, local *accountSet) types.Transactions {
-	drop := make(types.Transactions, 0, slots) // Remote underpriced transactions to drop
-	save := make(types.Transactions, 0, 64)    // Local underpriced transactions to keep
+	// If we have some local accountset, those will not be discarded
+	if !local.empty() {
+		// In case the list is filled to the brim with 'local' txs, we do this
+		// little check to avoid unpacking / repacking the heap later on, which
+		// is very expensive
+		discardable := 0
+		for _, tx := range *l.items {
+			if !local.containsTx(tx) {
+				discardable++
+			}
+			if discardable >= slots {
+				break
+			}
+		}
+		if slots > discardable {
+			slots = discardable
+		}
+	}
+	if slots == 0 {
+		return nil
+	}
+	drop := make(types.Transactions, 0, slots)               // Remote underpriced transactions to drop
+	save := make(types.Transactions, 0, len(*l.items)-slots) // Local underpriced transactions to keep
 
 	for len(*l.items) > 0 && slots > 0 {
 		// Discard stale transactions if found during cleanup
diff --git a/core/tx_list_test.go b/core/tx_list_test.go
index 3a5842d2e..d9f4eba26 100644
--- a/core/tx_list_test.go
+++ b/core/tx_list_test.go
@@ -17,7 +17,6 @@
 package core
 
 import (
-	"math/big"
 	"math/rand"
 	"testing"
 
@@ -51,20 +50,22 @@ func TestStrictTxListAdd(t *testing.T) {
 	}
 }
 
-func BenchmarkTxListAdd(t *testing.B) {
+func BenchmarkTxListAdd(b *testing.B) {
 	// Generate a list of transactions to insert
 	key, _ := crypto.GenerateKey()
 
-	txs := make(types.Transactions, 100000)
+	txs := make(types.Transactions, 2000)
 	for i := 0; i < len(txs); i++ {
 		txs[i] = transaction(uint64(i), 0, key)
 	}
 	// Insert the transactions in a random order
-	list := newTxList(true)
-	priceLimit := big.NewInt(int64(DefaultTxPoolConfig.PriceLimit))
-	t.ResetTimer()
-	for _, v := range rand.Perm(len(txs)) {
-		list.Add(txs[v], DefaultTxPoolConfig.PriceBump)
-		list.Filter(priceLimit, DefaultTxPoolConfig.PriceBump)
+	b.ResetTimer()
+	priceLimit := DefaultTxPoolConfig.PriceLimit
+	for i := 0; i < b.N; i++ {
+		list := newTxList(true)
+		for _, v := range rand.Perm(len(txs)) {
+			list.Add(txs[v], DefaultTxPoolConfig.PriceBump)
+			list.Filter(priceLimit, DefaultTxPoolConfig.PriceBump)
+		}
 	}
 }
diff --git a/core/tx_pool.go b/core/tx_pool.go
index 350acc81b..2a4a994d4 100644
--- a/core/tx_pool.go
+++ b/core/tx_pool.go
@@ -543,7 +543,11 @@ func (pool *TxPool) validateTx(tx *types.Transaction, local bool) error {
 	}
 	// Transactor should have enough funds to cover the costs
 	// cost == V + GP * GL
-	if pool.currentState.GetBalance(from).Cmp(tx.Cost()) < 0 {
+	cost, overflow := tx.CostU64()
+	if overflow {
+		return ErrInsufficientFunds
+	}
+	if pool.currentState.GetBalance(from).Uint64() < cost {
 		return ErrInsufficientFunds
 	}
 	// Ensure the transaction has more gas than the basic tx fee.
@@ -1059,8 +1063,8 @@ func (pool *TxPool) runReorg(done chan struct{}, reset *txpoolResetRequest, dirt
 
 	// Update all accounts to the latest known pending nonce
 	for addr, list := range pool.pending {
-		txs := list.Flatten() // Heavy but will be cached and is needed by the miner anyway
-		pool.pendingNonces.set(addr, txs[len(txs)-1].Nonce()+1)
+		highestPending := list.LastElement()
+		pool.pendingNonces.set(addr, highestPending.Nonce()+1)
 	}
 	pool.mu.Unlock()
 
@@ -1190,7 +1194,7 @@ func (pool *TxPool) promoteExecutables(accounts []common.Address) []*types.Trans
 		}
 		log.Trace("Removed old queued transactions", "count", len(forwards))
 		// Drop all transactions that are too costly (low balance or out of gas)
-		drops, _ := list.Filter(pool.currentState.GetBalance(addr), pool.currentMaxGas)
+		drops, _ := list.Filter(pool.currentState.GetBalance(addr).Uint64(), pool.currentMaxGas)
 		for _, tx := range drops {
 			hash := tx.Hash()
 			pool.all.Remove(hash)
@@ -1382,7 +1386,7 @@ func (pool *TxPool) demoteUnexecutables() {
 			log.Trace("Removed old pending transaction", "hash", hash)
 		}
 		// Drop all transactions that are too costly (low balance or out of gas), and queue any invalids back for later
-		drops, invalids := list.Filter(pool.currentState.GetBalance(addr), pool.currentMaxGas)
+		drops, invalids := list.Filter(pool.currentState.GetBalance(addr).Uint64(), pool.currentMaxGas)
 		for _, tx := range drops {
 			hash := tx.Hash()
 			log.Trace("Removed unpayable pending transaction", "hash", hash)
@@ -1457,6 +1461,10 @@ func (as *accountSet) contains(addr common.Address) bool {
 	return exist
 }
 
+func (as *accountSet) empty() bool {
+	return len(as.accounts) == 0
+}
+
 // containsTx checks if the sender of a given tx is within the set. If the sender
 // cannot be derived, this method returns false.
 func (as *accountSet) containsTx(tx *types.Transaction) bool {
diff --git a/core/tx_pool_test.go b/core/tx_pool_test.go
index 78290862e..be06577e3 100644
--- a/core/tx_pool_test.go
+++ b/core/tx_pool_test.go
@@ -1889,11 +1889,15 @@ func benchmarkFuturePromotion(b *testing.B, size int) {
 }
 
 // Benchmarks the speed of batched transaction insertion.
-func BenchmarkPoolBatchInsert100(b *testing.B)   { benchmarkPoolBatchInsert(b, 100) }
-func BenchmarkPoolBatchInsert1000(b *testing.B)  { benchmarkPoolBatchInsert(b, 1000) }
-func BenchmarkPoolBatchInsert10000(b *testing.B) { benchmarkPoolBatchInsert(b, 10000) }
+func BenchmarkPoolBatchInsert100(b *testing.B)   { benchmarkPoolBatchInsert(b, 100, false) }
+func BenchmarkPoolBatchInsert1000(b *testing.B)  { benchmarkPoolBatchInsert(b, 1000, false) }
+func BenchmarkPoolBatchInsert10000(b *testing.B) { benchmarkPoolBatchInsert(b, 10000, false) }
 
-func benchmarkPoolBatchInsert(b *testing.B, size int) {
+func BenchmarkPoolBatchLocalInsert100(b *testing.B)   { benchmarkPoolBatchInsert(b, 100, true) }
+func BenchmarkPoolBatchLocalInsert1000(b *testing.B)  { benchmarkPoolBatchInsert(b, 1000, true) }
+func BenchmarkPoolBatchLocalInsert10000(b *testing.B) { benchmarkPoolBatchInsert(b, 10000, true) }
+
+func benchmarkPoolBatchInsert(b *testing.B, size int, local bool) {
 	// Generate a batch of transactions to enqueue into the pool
 	pool, key := setupTxPool()
 	defer pool.Stop()
@@ -1911,6 +1915,10 @@ func benchmarkPoolBatchInsert(b *testing.B, size int) {
 	// Benchmark importing the transactions into the queue
 	b.ResetTimer()
 	for _, batch := range batches {
-		pool.AddRemotes(batch)
+		if local {
+			pool.AddLocals(batch)
+		} else {
+			pool.AddRemotes(batch)
+		}
 	}
 }
diff --git a/core/types/transaction.go b/core/types/transaction.go
index da691bb03..347db2da0 100644
--- a/core/types/transaction.go
+++ b/core/types/transaction.go
@@ -25,6 +25,7 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/common/hexutil"
+	"github.com/ethereum/go-ethereum/common/math"
 	"github.com/ethereum/go-ethereum/crypto"
 	"github.com/ethereum/go-ethereum/rlp"
 )
@@ -41,6 +42,7 @@ type Transaction struct {
 	hash atomic.Value
 	size atomic.Value
 	from atomic.Value
+	cost atomic.Value
 }
 
 type txdata struct {
@@ -258,6 +260,15 @@ func (tx *Transaction) Cost() *big.Int {
 	return total
 }
 
+func (tx *Transaction) CostU64() (uint64, bool) {
+	if tx.data.Price.BitLen() > 63 || tx.data.Amount.BitLen() > 63 {
+		return 0, false
+	}
+	cost, overflowMul := math.SafeMul(tx.data.Price.Uint64(), tx.data.GasLimit)
+	total, overflowAdd := math.SafeAdd(cost, tx.data.Amount.Uint64())
+	return total, overflowMul || overflowAdd
+}
+
 // RawSignatureValues returns the V, R, S signature values of the transaction.
 // The return values should not be modified by the caller.
 func (tx *Transaction) RawSignatureValues() (v, r, s *big.Int) {