# When a difficulty change reaches the upper or lower bound (4x current), what is the implied impact on time per block?

Can someone work out the math that occurs with Bitcoin and Litecoin when the target changes to the hard coded minimum and maximum value, with respect to time?

In other words, if a lot of hashpower is added to the network and target increases by 4x, that is the upper bound. How many blocks can be created right before the throttle of 4x is taken by the network?

I'm trying to calculate the affect throttling has on the number of blocks generated per hour.

Question

What is the average time per block, right before the network adjusts to the 4x limit, when the hash power is added to the network?

If I were to guess, right before that 4x limit was reached, 1 block is generated every 2.5 minutes for Bitcoin, and 1 block every 45 seconds for litecoin.

Furthermore any hashpower added (or removed) beyond the 4x multipler will not cause a network adjustment and infinitely many blocks may be created in that interval.

Why I want to know this...

If a lot of hashpower is added to the Litecoin network, which already generates blocks (one every 2.5 minutes) then there will be more blocks generated, increasing the risk of a chain split.

I ultimately want to understand how the chain split will cause wasted computation by peers as their blocks are discarded by the longest chain.