diff --git a/cmd/utils/flags.go b/cmd/utils/flags.go
index 52030c76ea..58b470e6b5 100644
--- a/cmd/utils/flags.go
+++ b/cmd/utils/flags.go
@@ -149,7 +149,7 @@ var (
 	GasPriceFlag = cli.StringFlag{
 		Name:  "gasprice",
 		Usage: "Sets the minimal gasprice when mining transactions",
-		Value: new(big.Int).Mul(big.NewInt(500), common.Shannon).String(),
+		Value: new(big.Int).Mul(big.NewInt(50), common.Shannon).String(),
 	}
 
 	UnlockedAccountFlag = cli.StringFlag{
@@ -309,12 +309,12 @@ var (
 	GpoMinGasPriceFlag = cli.StringFlag{
 		Name:  "gpomin",
 		Usage: "Minimum suggested gas price",
-		Value: new(big.Int).Mul(big.NewInt(1), common.Szabo).String(),
+		Value: new(big.Int).Mul(big.NewInt(50), common.Shannon).String(),
 	}
 	GpoMaxGasPriceFlag = cli.StringFlag{
 		Name:  "gpomax",
 		Usage: "Maximum suggested gas price",
-		Value: new(big.Int).Mul(big.NewInt(100), common.Szabo).String(),
+		Value: new(big.Int).Mul(big.NewInt(100), common.Shannon).String(),
 	}
 	GpoFullBlockRatioFlag = cli.IntFlag{
 		Name:  "gpofull",
diff --git a/core/chain_util.go b/core/chain_util.go
index 326bf13fb2..f8dd4c1d7d 100644
--- a/core/chain_util.go
+++ b/core/chain_util.go
@@ -69,12 +69,27 @@ func CalcTD(block, parent *types.Block) *big.Int {
 
 // CalcGasLimit computes the gas limit of the next block after parent.
 // The result may be modified by the caller.
+// This is miner strategy, not consensus protocol.
 func CalcGasLimit(parent *types.Block) *big.Int {
-	decay := new(big.Int).Div(parent.GasLimit(), params.GasLimitBoundDivisor)
+	// contrib = (parentGasUsed * 3 / 2) / 1024
 	contrib := new(big.Int).Mul(parent.GasUsed(), big.NewInt(3))
 	contrib = contrib.Div(contrib, big.NewInt(2))
 	contrib = contrib.Div(contrib, params.GasLimitBoundDivisor)
 
+	// decay = parentGasLimit / 1024 -1
+	decay := new(big.Int).Div(parent.GasLimit(), params.GasLimitBoundDivisor)
+	decay.Sub(decay, big.NewInt(1))
+
+	/*
+		strategy: gasLimit of block-to-mine is set depending on parent's
+		gasUsed value.  if parentGasUsed > parentGasLimit * (2/3) then we
+		increase it, otherwise lower it (or leave it unchanged if it's right
+		at that usage) the amount increased/decreased depends on how far away
+		from parentGasLimit * (2/3) parentGasUsed is.
+
+		however, if we're below the target (GenesisGasLimit) we increase the
+		limit as much as we can (parentGasLimit / 1024 -1)
+	*/
 	gl := new(big.Int).Sub(parent.GasLimit(), decay)
 	gl = gl.Add(gl, contrib)
 	gl = gl.Add(gl, big.NewInt(1))
diff --git a/params/protocol_params.go b/params/protocol_params.go
index b1a6757b19..dcc17e05d7 100755
--- a/params/protocol_params.go
+++ b/params/protocol_params.go
@@ -39,8 +39,8 @@ var (
 	EcrecoverGas           = big.NewInt(3000)   //
 	Sha256WordGas          = big.NewInt(12)     //
 
-	MinGasLimit     = big.NewInt(5000) // Minimum the gas limit may ever be.
-	GenesisGasLimit = big.NewInt(5000) // Gas limit of the Genesis block.
+	MinGasLimit     = big.NewInt(5000)    // Minimum the gas limit may ever be.
+	GenesisGasLimit = big.NewInt(3141592) // Gas limit of the Genesis block.
 
 	Sha3Gas              = big.NewInt(30)     // Once per SHA3 operation.
 	Sha256Gas            = big.NewInt(60)     //