Originally Posted by
rge
you will have 6x multi, 8x multi, 10x multi, etc available. There is no 9x multi, so no 9x200 or 1800. So for 200 bclk, you can run 1600 and 2000. For example on my cpu i7 940, I can run 1600 mem (8x mem x 200 bclk) with 1.65v DRAM and 1.33qpi/vtt. Both of those are near max intel recommended volts for memory and qpi/vtt, but fine for 24/7 use. Uncore is 17x or 18x, for 3400 mhz or 3600 mhz uncore.
Uncore must be 2x memory or no boot. So now try 2000 mem. To run 2000 mem (I do for benching), I must use 10x mem multi 10x200 bclk, and thus 20x uncore at minimum. I need 1.64 qpi/vtt and 1.96 DRAMv to do so, way outside intel recommended limits, and that is for benching stability (may need more v for 24/7) albeit arena chess, which is like stress testing for 5 minutes....and I use 22x uncore or 4400 mhz, though could use 20x which would be little easier. So if you are willing to run high volts for 24/7, then you can run 2000. Even if unlike me, you buy ram rated for 2000 which will run at 1.65 v DRAM, it still requires high VTT/qpi and probably still high DRAM to drive uncore at 4000 min. But you must assume the risk of high volts, and the benefit is next to nothing in real world apps between running 1600 and 2000, as that has been shown time and again. Even benching you are talking 1% improvement in only some benches, not all, if that...1% makes diff in benching, but not so much on 24/7.