Rampage Extreme / E8600 / OCZ3P18002GK (2x1GB)/ 450x9.5 / 1:2 - screenshot + settings
Here's where I've got to so far: nothing impressive but further than I thought I might get using OCZ with 1:2 on this board :)
http://i447.photobucket.com/albums/q...8_P958_8_L.jpg
Memory and NB stability
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To keep voltages at a min and just get the memory up to rated speed and timings, I worked up in 5mhz steps from 400-450fsb with 1:2, tuning up/down to min stable voltages at each stage. This took much too long but was still worth it for getting to know where I actually was. For that reason I've stuck with 0403 for now.
450fsb with 1:2, was unstable even at 1.45VNB and 1.95VDIMM with 100ps NB CLOCK SKEW delay (set manually to 100 at 410fsb).
Setting NB CLOCK SKEW to 200ps worked very well - at 450fsb, using AUTO / Normal / 100 / 300 gave me early freezes or errors in Prime or Intel (Linpack) and extra voltage did not help, but with 200, it behaves.
After 'finding' 200ps at 450fsb, I was able to lower VNB to 1.405V (min found) and VDIMM to 1.908v (min found) - both 0.05V lower (and stable) than where I was with 100ps (and unstable). 1.405VNB for PL7 @ 450/900/8-8-8-24 with 2x1GB is still a bit higher than I was hoping for though. DRAM SKEWS and NB GTL are currently on AUTO.
At these settings, ClockTwister causes instability if set to Strong or Stronger but at least the 200ps NB CLOCK SKEW allowed Moderate instead of Light.
Unfortunately, can't POST above 430fsb with PL6 and 1:2 (hangs on DET RAM) - tried VNB up to 1.48v + extra VDIMM but doesn't help. Will go back later and try sorting this but for now I'm going to push up from 450fsb keeping to 1:2 with PL7.
With PL7, Clocktwister on Moderate, 2N and slack 8-8-8-8-24, I'm losing memory performance all over the place: gives approx 10.5Gb/s Read with 50ns in Everest at this time.
Thanks to Tony at OCZ for providing some great info in his P5E3 Premium and X48 guides over there - I had a much better idea of when and why I might need to skew after finding those - I think a lot of the info is generally applicable to any X48 board and memory, not just the P5E3 Prem and OCZ.
http://www.ocztechnologyforum.com/fo...ad.php?t=41042
http://www.ocztechnologyforum.com/fo...ad.php?t=40746
CPU Voltage, temps and stability
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After the memory was stable at 900mhz (Orthos/IntelBurn(Linpack)/MemtestHCI/Memtestx86), I found the min CPUVCORE (LLC disabled) for each multi up to 9.5. 4275mhz (9.5) needs 1.33125V (set in BIOS) for 8 hour Prime. High for E8600, but my VID is 1.25 and this chip runs quite cool (Q820A606).
I set CPU clock skew to NORMAL at 400fsb but have not yet found benefit to either 100ps or 200ps delays for Vcore/stability.
Found no need (with dual-core) for extra CPUVTT or PLL at these levels - set manually to 1.10V and 1.510V (both min). Not expecting 450-500fsb to require extra CPUVTT or PLL either. GTLs all at AUTO.
CPU cooler is Noctua NH-U12P + 1 x NF-P12 fan. Hits 55c under Intel at 4275mhz/1.33125V, so it won't get that hot elsewhere. Have second fan for CPU cooler but not tried yet. Max temp shown in screen shot is Real Temp 2.70 which sets TJmax at 95c, which I think is correct (CoreTemp 99.3 auto sets TJmax at 100c but agrees with all temp changes)
Edit: Intel official TjMax 100c (add 5c to quoted temps)
I'm only using Intel for max CPU temps and quick full system tests (10xpass) - errors in here will always give me errors or worse in Prime, so it's quicker for rough stability. Surprisingly to me, condsidering the CPU temps generated by Intel, I found a 0.03125Vcore difference between Intel stable and Prime/Orthos stable with my board/CPU for 450x9.5 - Prime needs the extra Vcore or will restart/freeze/error on small FFTs. This Vcore difference showed the same in OCCT too (OCCT passes with 0.03125 less Vcore than Prime or Orthos). I'm not using LLC.