I upgraded my ram from the Corsair Dominator 6GB CM3X2G1600C8D to Corsair Dominator GT 24GB CMT12GX3M3A2000C9 and my previous overclock has failed. I've reset my BIOS setting to its default state. I had previously followed the overclocking guide on bit-tech and had a stable 4ghz overclock. Does anyone have any ideas what BIOS settings I should try changing? I've been at this for the last 6hours!!
I have the same board and CPU. Tell me your settings, and I'll try to help. Although, it should be fairly easy to run 20 multi at 200BLCK, with the ram at 1604MHz and 1.64vdimm. Depending on your CPU, 1.3v should be enough Vcore for 4GHz, with a little bump on QPI/Dram voltage to help the BCLK. IOH might need a liitle extra volts, although 200BLCK is hardly extreme. Enable loadline calibration, and switch off Spread Spectrum. Thinking about it - I'm not sure how much of an impact filling all six memory slots will have on overclocking - however, as I'll be fitting 6x2GB 2133 sticks next week I'm sure I'll find out. **Just read the above comments - looks like it's a significant factor**
Thanks for the help guys. I've managed to o/c to 4ghz but have had to underclock the ram. Would be grateful for any help on getting the Ram settings up and whether you think any of my voltages are bit high. NB. Not sure how stable these settings are as I still need to run Prime95 Here are my settings: Ai Overclock Tuner Manual CPU ratio 20 Intel Speedstep Off BCLCK Frequency 200 PCIE Frequency 100 DRAM Frequency 1603 UCLCK Frequency 3208 QPI Link Data Auto CPU Voltage 1.3 CPU PLL Voltage 1.96 QPI/Dram Core Volt 1.35 IOH Voltage Auto IOH PCIE Voltage Auto ICH Voltage Auto ICH PCIE Voltage Auto DRAM Bus Voltage 1.66 All other settings Auto ************************** Load Line On CPU Differential Amp 800Mv CPU Clock Skew Auto CPU spread spectrum Off IOH clock skew Auto PCIE spread spectrum Auto BIOS: Advance (CPU Configuration) CPU ratio 20 C1E Support Off Hardware Prefetcher On Adjacent Cache Line On MPS & ACPI MADT Modern Intel Virtualisation Tech On CPU TM Function On Execute Disable Bit On Intel HT Tech On Active Processor Cores All A20M Off Intel Speed Step Off Intel C-State Tech Off
191x21 is a much better approach to 4GHz because, for some unknown reason, the even multipliers are usually unstable or (at best) extremely hard to get stable. I had my 920 for a long time and never ran it with an even multi... ever; it was always either 191x21 or 200x21. BCLK holes are another potential setback, and they are more evident with my 990X than they have ever been with any other CPU. My PC won't even boot with 152 BCLK... no matter what I do, it just doesn't happen.
Also, take your IOH voltage out of Auto and try it at 1.20V. Probably asking the obvious here but, have you ruled out the possibility of a bad RAM module? One out of six is far more likely than one out of three.
These are just minor points but might make a difference CPU PLL Voltage 1.96 - Seems quite high CPU Differential Amp 800Mv - Change to Normal PCIE spread spectrum Auto - Change to Off The main thing to experiment with is the QPI/Dram Core Volt. The IMC might not be a good one on that chip so you may need to go even higher for 1600MHz and a lot higher (up to 1.6v) for 2000MHz. As an example my 920 needed 1.38v for 1600MHz and 1.58v for 2000MHz at an overclock of 4.2GHz.
Virtualisation can hamper an overclock too - not normally 4GHz, but I don't know the impact of six DIMMs on that. Try turning it off, epsecially if you don't need it.
Thanks for all the suggestions. Latest update on the o/c is that I've got it to 3.6ghz and the Dram frequency running at 1904Mhz. Changes to the above settings I made are: Ai Overclock Tuner - XMP CPU ratio - 19 Bclck frequency - 190 Dram frequency - 1904 Uclck frequency - 3808 CPU pll voltage - 1.9 (is this still a bit high?) Qpi/Dram core voltage - 1.45 Ioh voltage - 1.2 ********************* CPU differential amp - Auto Pcie spread spectrum - Off Still need to run prime95 though. I did run memtest86+ and win 7 memory diagnostic, both returned no error reports
A reasonable start. One thing I'd forgotten about is that the mobo might default to aggressive memory timings when you reset the BIOS so make sure you set those manually if you haven't already done so. I'd drop the CPU PLL to default (1.80v?) and then only increase it if the overclock is unstable.
In 'AI Tweaker' go to 'DRAM Timing Mode' and then set the first 4 timings manually. The timings are, I think, 9-11-9-27 but check the label as it will be on there and could be 9-10-9-27. Changing the 'DRAM Timing Mode' to 2N might also aid stability.
Ok, thanks. I'll give that a go. I've got my o/c running at 4ghz with the following changes: CPU ratio - 21 CPU PLL Voltage - 1.8 Dram bus Voltage - 1.64 I had reduced the QPI/Dram core voltage to 1.4 but that failed so back up to 1.45. I'll manually set the memory timings and then run prime95 overnight. If it's still going in the morning I'll leave it running so that I get a good 18hrs of testing.
If the timing were set lower than what they're supposed to be you could try reducing the QPI voltage but it may be that your IMC (Integrated Memory Controller) on the CPU isn't brilliant especially with the 6 sticks of RAM. For the minuscule loss of performance I'd suggest dropping the RAM a notch to around 1523MHz. I've never had problems on the later version of that mobo with setting a BCLK of 200 and a Multi of 20 to get 4GHz and doing that would mean you could run the RAM at 1600MHz.
I have a P6T SE and a I7 930. Would be good to see your settings/pics/temps as i'm thinking of clocking mine to 4gh or close as possible.always been unsure what settings to apply then i think ahhh il leave it!!
Ok guys, after a lot of tweeking here are my stable starting overclock settings (6 March column) and the settings I currently have. BIOS - AI Tweeker 06-Mar 10-Mar .................................@4ghz...@3.99 Ai Overclock Tuner....... XMP...... XMP CPU ratio......................20.........21 Intel Speedstep ...........Off BCLCK Frequency..........200......190 PCIE Frequency.............100 DRAM Frequency............1603....1904 UCLCK Frequency..........3208.....3809 QPI Link Data................Auto CPU Voltage..................1.3........1.35 CPU PLL Voltage............1.8........1.86 QPI/Dram Core Volt.......1.35......1.5 IOH Voltage...................1.2........1.26 IOH PCIE Voltage..........Auto ICH Voltage...................Auto ICH PCIE Voltage..........Auto DRAM Bus Voltage.........1.64......1.66 All other settings...........Auto *********************************************** Load Line...................On CPU Differential Amp...Auto CPU Clock Skew..........Auto CPU spread spectrum...Off IOH clock skew...........Auto PCIE spread spectrum..Off BIOS - Advanced (CPU Configuration) CPU ratio......................20 C1E Support.................Off Hardware Prefetcher....On Adjacent Cache Line P..On MPS & ACPI MADT.........Modern Intel Virtualisation Tech.On CPU TM Function...........On Execute Disable Bit.......On Intel HT Tech................On Active Processor Cores.All A20M............................Off Intel Speed Step...........Off Intel C-State Tech.........Off At the moment, yesterdays settings are still holding but I may try to reduce the cpu and cpu pll voltages a fraction. At 1.5v the qpi/Dram voltage is a little higher than I would like (just because this is my first o/c and seeing the figure in red, in the bios, is a bit scarey!) I'm quite happy with an o/c to 3.99ghz running with the ram at 1904mhz. Let me know what you guys think and if you have any advice on my settings.
Have you changed the RAM timings to match their spec? You're going to have a high QPI voltage if you run your RAM close to their rated speed. For the slight loss of bandwidth running at a BCLK of 200 with 1600MHz means a lower QPI voltage and a bit less heat. Also you'd probably be able to reduce the DRAM voltage a bit. As has been mentioned before unless you use virtualisation disabling Intel Virtualisation Tech could help stability. I'd run it with Speedstep on. Unless you're exploring the higher reaches of overclocking it's unlikely to affect stability.
The dram timings are at 9-11-9-27 with timing mode at 2N. I'll switch off Virtualisation as suggested. So if I overclock with 21 x 200 and drop the ram to 1603mhz should I get better performance than with 21x190 with ram at 1904mhz?
