I have 4 BFL Monarch miners (750Gh).  Two of them are performing @ 95% (hashrate/poolrate) and the other two have problems. One is @ 360Gh (94%) (hashrate/poolrate), and the other is pushing 950Gh, but on slushpool, it's only showing 315Gh (32%).  It does not matter which computer I'm using the cgminer software.

'puter: Win 7 Desktop & Win8.3 laptop
software: CGMiner 4.10.0
Pool: SlushPool

How do I go about diagnosing the problem?

TIA