Proof of time specification has BLOCK_AUTHORING_DELAY parameter set to 4 slots, which is ~4 seconds. This means farmer who produced a solution will have to wait 4 more slots before they can actually send it to the network.
This delay reduces performance difference between farmers since it no longer matters how quickly farmer can produce a solution, as long as it is less than 4 seconds, it is good enough and will make no difference.
For 3f farmer had ~750ms to audit, prove and propose (primarily sign) a block. In 3g farmer has 4 seconds to audit and prove, proposing is still ~750ms, but farmer does less work there now.