Posted 04 October 2012 - 14:29
It could be due to the higher latency but that is pretty unusual, the memory bus speed goes up but the copy speed (and only the copy speed) drops. I'm guessing latency has something to do with it but I've never full understood RAM overclocking.
EDIT: You could try lowering your latencies back down to where they were (might have to give more voltage to the ram), or put your overclock back to 3.2 Ghz, and increase the latencies to where they are when you go to 3.4 Ghz....that should give you a better direct comparison of how latency affects copy speed (if it does at all).
EDIT2: From a quick google, latency is basically the wait time between operations (in cycles), so if your ram has a latency of 5 (such as your 3.2Ghz), it will wait 5 cycles between reading and writing. A latency of 6 would wait 6 cycles. Obviously this wouldn't affect read or write speeds, but when copying you are doing more than 1 operation so the longer the wait in-between, the slower the overall copy (when measured over the same amount of time or using the same amount of data).