diff --git a/cmd/geth/main.go b/cmd/geth/main.go
index e00b139c0d..f2497ccf42 100644
--- a/cmd/geth/main.go
+++ b/cmd/geth/main.go
@@ -27,8 +27,10 @@ import (
 	"io/ioutil"
 	"os"
 	"path"
+	"path/filepath"
 	"runtime"
 	"strconv"
+	"strings"
 	"time"
 
 	"github.com/codegangsta/cli"
@@ -601,12 +603,32 @@ func dump(ctx *cli.Context) {
 }
 
 func makedag(ctx *cli.Context) {
-	chain, _, _ := utils.GetChain(ctx)
-	pow := ethash.New(chain)
-	fmt.Println("making cache")
-	pow.UpdateCache(0, true)
-	fmt.Println("making DAG")
-	pow.UpdateDAG()
+	args := ctx.Args()
+	wrongArgs := func() {
+		utils.Fatalf(`Usage: geth makedag <block number> <outputdir>`)
+	}
+	switch {
+	case len(args) == 2:
+		blockNum, err := strconv.ParseUint(args[0], 0, 64)
+		dir := args[1]
+		if err != nil {
+			wrongArgs()
+		} else {
+			dir = filepath.Clean(dir)
+			// seems to require a trailing slash
+			if !strings.HasSuffix(dir, "/") {
+				dir = dir + "/"
+			}
+			_, err = ioutil.ReadDir(dir)
+			if err != nil {
+				utils.Fatalf("Can't find dir")
+			}
+			fmt.Println("making DAG, this could take awhile...")
+			ethash.MakeDAG(blockNum, dir)
+		}
+	default:
+		wrongArgs()
+	}
 }
 
 func version(c *cli.Context) {
diff --git a/cmd/utils/flags.go b/cmd/utils/flags.go
index c013510d82..1fdc8dfe51 100644
--- a/cmd/utils/flags.go
+++ b/cmd/utils/flags.go
@@ -316,7 +316,7 @@ func GetChain(ctx *cli.Context) (*core.ChainManager, common.Database, common.Dat
 
 	eventMux := new(event.TypeMux)
 	chainManager := core.NewChainManager(blockDb, stateDb, eventMux)
-	pow := ethash.New(chainManager)
+	pow := ethash.New()
 	txPool := core.NewTxPool(eventMux, chainManager.State, chainManager.GasLimit)
 	blockProcessor := core.NewBlockProcessor(stateDb, extraDb, pow, txPool, chainManager, eventMux)
 	chainManager.SetProcessor(blockProcessor)
diff --git a/core/chain_makers.go b/core/chain_makers.go
index 73c2205f44..5cd7ab4abb 100644
--- a/core/chain_makers.go
+++ b/core/chain_makers.go
@@ -14,8 +14,8 @@ import (
 // So we can generate blocks easily
 type FakePow struct{}
 
-func (f FakePow) Search(block pow.Block, stop <-chan struct{}) (uint64, []byte, []byte) {
-	return 0, nil, nil
+func (f FakePow) Search(block pow.Block, stop <-chan struct{}) (uint64, []byte) {
+	return 0, nil
 }
 func (f FakePow) Verify(block pow.Block) bool { return true }
 func (f FakePow) GetHashrate() int64          { return 0 }
diff --git a/eth/backend.go b/eth/backend.go
index a8b0fae500..5acef2ded6 100644
--- a/eth/backend.go
+++ b/eth/backend.go
@@ -220,7 +220,7 @@ func New(config *Config) (*Ethereum, error) {
 
 	eth.chainManager = core.NewChainManager(blockDb, stateDb, eth.EventMux())
 	eth.downloader = downloader.New(eth.chainManager.HasBlock, eth.chainManager.GetBlock)
-	eth.pow = ethash.New(eth.chainManager)
+	eth.pow = ethash.New()
 	eth.txPool = core.NewTxPool(eth.EventMux(), eth.chainManager.State, eth.chainManager.GasLimit)
 	eth.blockProcessor = core.NewBlockProcessor(stateDb, extraDb, eth.pow, eth.txPool, eth.chainManager, eth.EventMux())
 	eth.chainManager.SetProcessor(eth.blockProcessor)
@@ -318,7 +318,6 @@ func (s *Ethereum) PeersInfo() (peersinfo []*PeerInfo) {
 
 func (s *Ethereum) ResetWithGenesisBlock(gb *types.Block) {
 	s.chainManager.ResetWithGenesisBlock(gb)
-	s.pow.UpdateCache(0, true)
 }
 
 func (s *Ethereum) StartMining() error {
diff --git a/miner/agent.go b/miner/agent.go
index 547fdfbef7..b2f89aaaba 100644
--- a/miner/agent.go
+++ b/miner/agent.go
@@ -85,7 +85,7 @@ func (self *CpuMiner) mine(block *types.Block) {
 	self.chMu.Unlock()
 
 	// Mine
-	nonce, mixDigest, _ := self.pow.Search(block, self.quitCurrentOp)
+	nonce, mixDigest := self.pow.Search(block, self.quitCurrentOp)
 	if nonce != 0 {
 		block.SetNonce(nonce)
 		block.Header().MixDigest = common.BytesToHash(mixDigest)
diff --git a/miner/miner.go b/miner/miner.go
index 8839563702..bff0026dc4 100644
--- a/miner/miner.go
+++ b/miner/miner.go
@@ -3,7 +3,6 @@ package miner
 import (
 	"math/big"
 
-	"github.com/ethereum/ethash"
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/state"
@@ -41,13 +40,7 @@ func (self *Miner) Mining() bool {
 func (self *Miner) Start(coinbase common.Address) {
 	self.mining = true
 	self.worker.coinbase = coinbase
-
-	if self.threads > 0 {
-		self.pow.(*ethash.Ethash).UpdateDAG()
-	}
-
 	self.worker.start()
-
 	self.worker.commitNewWork()
 }
 
diff --git a/pow/dagger/dagger.go b/pow/dagger/dagger.go
index f2d65e8efe..b941c0eeb5 100644
--- a/pow/dagger/dagger.go
+++ b/pow/dagger/dagger.go
@@ -6,8 +6,8 @@ import (
 	"math/rand"
 	"time"
 
-	"github.com/ethereum/go-ethereum/crypto/sha3"
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/crypto/sha3"
 	"github.com/ethereum/go-ethereum/logger"
 )
 
@@ -44,7 +44,7 @@ func (dag *Dagger) Find(obj *big.Int, resChan chan int64) {
 	resChan <- 0
 }
 
-func (dag *Dagger) Search(hash, diff *big.Int) ([]byte, []byte, []byte) {
+func (dag *Dagger) Search(hash, diff *big.Int) (uint64, []byte) {
 	// TODO fix multi threading. Somehow it results in the wrong nonce
 	amountOfRoutines := 1
 
@@ -69,7 +69,7 @@ func (dag *Dagger) Search(hash, diff *big.Int) ([]byte, []byte, []byte) {
 		}
 	}
 
-	return big.NewInt(res).Bytes(), nil, nil
+	return uint64(res), nil
 }
 
 func (dag *Dagger) Verify(hash, diff, nonce *big.Int) bool {
diff --git a/pow/ezp/pow.go b/pow/ezp/pow.go
index bd2927fe8f..c838dd5ecc 100644
--- a/pow/ezp/pow.go
+++ b/pow/ezp/pow.go
@@ -32,7 +32,7 @@ func (pow *EasyPow) Turbo(on bool) {
 	pow.turbo = on
 }
 
-func (pow *EasyPow) Search(block pow.Block, stop <-chan struct{}) (uint64, []byte, []byte) {
+func (pow *EasyPow) Search(block pow.Block, stop <-chan struct{}) (uint64, []byte) {
 	r := rand.New(rand.NewSource(time.Now().UnixNano()))
 	hash := block.HashNoNonce()
 	diff := block.Difficulty()
@@ -57,7 +57,7 @@ empty:
 	for {
 		select {
 		case <-stop:
-			return 0, nil, nil
+			return 0, nil
 		default:
 			i++
 
@@ -67,7 +67,7 @@ empty:
 
 			sha := uint64(r.Int63())
 			if verify(hash, diff, sha) {
-				return sha, nil, nil
+				return sha, nil
 			}
 		}
 
@@ -76,7 +76,7 @@ empty:
 		}
 	}
 
-	return 0, nil, nil
+	return 0, nil
 }
 
 func (pow *EasyPow) Verify(block pow.Block) bool {
diff --git a/pow/pow.go b/pow/pow.go
index 3908e5f761..73984a4aee 100644
--- a/pow/pow.go
+++ b/pow/pow.go
@@ -1,7 +1,7 @@
 package pow
 
 type PoW interface {
-	Search(block Block, stop <-chan struct{}) (uint64, []byte, []byte)
+	Search(block Block, stop <-chan struct{}) (uint64, []byte)
 	Verify(block Block) bool
 	GetHashrate() int64
 	Turbo(bool)