GasLimit field type different on Ethereum clients?

[mmrozek]

Equation 37 refers that gasLimit should be a natural number. Why couldn't it be bound to N256?

I am confused because various Ethereuem clients implement this field in different ways:

• Parity: https://github.com/paritytech/parity-ethereum/blob/master/ethcore/types/src/header.rs#L79
• Geth: https://github.com/ethereum/go-ethereum/blob/master/core/types/block.go#L80

[nicksavers]

Not limiting the gasLimit allows it to be as high as needed without a hard fork. However current hardware can't even process gas higher than 2^32, so clients don't need to support N256 yet.

[nicksavers]

Keep an eye on ethereum/EIPs#106 and ethereum/EIPs#1985.