my 1066 is running @ 800

It maybe something Im overlooking.

Some background. I was using 4x1GB OCZ platinum DDR2 800 for some time. But felt its always held me back in terms of overclocking (I couldnt push e6600 stable past 3.5, it got replaced by an e8400 which wouldnt go stable past 3.8).

My motherboard is: P5K Premium BIOS 1101

Well RAM is considerably cheap these days, and as Im sitting here with some broken ribs, I was looking for a project.

So which brings it around. I decided to buy 2x2GB Corsair XMS2 PC2 8500C5.

It was delivered this morning, so I took the time to top the reservoir up and some general maintenance inside the case, and pop my new RAM in.

I then reset all my OC values and started from scratch, first boot I went for stock settings, to check all is fine, yet it booted at 800.

So I went in and changed it manually to 1066, wouldnt boot, sat with black screen. So I upped the voltage to 2.15. Still wouldnt boot.

So I defaulted the BIOS and set it all back up again, booted with stock settings, still 800.

What am I doing wrong?

Those are Powerchip ICs. They should do ~1066 5-5-5-15 at 2.0v
The most common cause for instability is low tRFC. It needs to be ~55
Download Memset and you can see your subtimings from Windows:http://www.tweakers.fr/memset.html

Readings from everest.

DIMM1: Corsair XMS2 CM2X2048-8500C5 2 GB DDR2-800 DDR2 SDRAM

I could get to 4.05, but it wasnt stable. To do it I dropped back to 1:1 and pushed it.

My ram volts would have been 2.15 and CPU was probably 1.2785 or something. Id be able to sit on the desktop and do mundane things, but 5 mins in CoD5 and Id BSOD.

Anyways, any help with my ram please?

Try increasing the North Bridge voltage... take it off AUTO and manually change it to 1.40v (if I remember right the lowest setting is 1.25v, with the next being 1.40v). If there's a setting available between 1.25 and 1.40v like 1.3 or 1.35v, then try selecting one of those instead.

Ill try it, but would this make my board see my ram at its native 8500, as opposed to 6400?

Eclectic said:

Ill try it, but would this make my board see my ram at its native 8500, as opposed to 6400?

Click to expand...

I thought you mentioned it wouldn't POST when setting the RAM to 1066 MHz.

Ya, I figured I hadnt made myself clear enough.

I shouldnt have to set it to 1066 right? Shouldnt the board just detect its 1066 and boot it so, if the settings are stock?

Ive took a couple of pics from my phone (shakey hands :/). Now to try be clear. my 1066 ram is booting at 800. why?

Eclectic said:

Shouldnt the board just detect its 1066 and boot it so, if the settings are stock?

Click to expand...

No, because the JEDEC #2 standard is 800 MHz (PC2-6400), while EPP is 1066 MHz (PC2-8500). What this means is that it POSTs using a 333/800 NB Strap (5:6 divider / ratio), so at a default FSB of 333 MHz the RAM is running at the JEDEC standard of 800 MHz. You need to manually change the strap to 333/1066 (5:8 divider), in order to end up with a DRAM frequency of 1066 MHz at a default FSB of 333 MHz. This while matching the four primary RAM timings to the SPD of 5-5-5-15-2T at 2.0 Vdimm (or whatever the SPD timings are for your particular RAM).

Thank you sir, the highest strap I had was 400, which its now set to.

Thank you