RAM: Stable 4x1GB DDR2 at 1066MHz on Rampage Formula?

Hi,
I'm trying to get an ASUS Rampage Formula (Intel X38/X48 chipset, BIOS lists the chipset as "Bearlake") to run stably with a full set of four Corsair 1GB kits (P/N CM2X1024-8500C5D). I can get this to work fine at 800MHz memory clock and 1.8V Vdram, but if I switch the RAM timings over to manual and use the ones from the SPD/EPP data (as shown by CPU-Z), the machine either crashes before finishing POST or fails Memcheck badly. On rare occasions it's gotten to the start of the Linux kernel load process and then barfed with a Kernel Panic.

I've tried:
- 800MHz, all settings on auto, 1.8V. Works fine, stable config.
- 1066MHz, all settings on auto, 2.1V. Won't finish POST (had to hit Clear CMOS)
- 1066MHz, manual timings (from CPU-Z data -- 5:5:5:15, 2T, 2.1V; couldn't see anywhere to enter Trc=22 though). Won't POST.
- Increased Northbridge voltage slightly, up to various voltages from 1.35V to 1.49V (the default is 1.35V). Best I got was being able to start Memcheck86+ and have it crash within a few seconds.
- Increased Vdram from 2.1V to 2.14V and then 2.19V. Might have helped a little, but not much.

Things I haven't tried:
- Playing with the "DRAM Voltage Ref" voltage. This is currently on Auto, which seems to mean "1.0V and some change".


Can anyone suggest a way I might be able to get this machine to run stable at 1066MHz Fdram, or am I stuck with the not especially appealing options of pulling two of the four sticks, or replacing the whole lot with a 2-stick 4GB kit?

I should note that all four sticks worked fine at 1066MHz on my previous board (ASUS P5N72T Deluxe, nForce 780i chipset). I don't think I even had to change the voltages (aside from the DRAM supply voltage)...

Thanks,
Phil.

The nForce chips could unlock the FSB from the RAM clock speed so on a Intel chip its locked so that if the ram is set to 1066MHz but you increased the FSB the ram speed will increase regardless.

Apart from that BIOS update?

Quote:

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Originally Posted by LegacyOne

The nForce chips could unlock the FSB from the RAM clock speed so on a Intel chip its locked so that if the ram is set to 1066MHz but you increased the FSB the ram speed will increase regardless.

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So what do I need to do, find a RAM speed that's an integer multiple of the FSB (or very close)?

I did try F_dram = 1002MHz, but didn't get anywhere with that either. The machine got into Memcheck, but spewed out a ton of errors.

Quote:

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Originally Posted by LegacyOne

Apart from that BIOS update?

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The board came with the latest BIOS -- 0902...

Thanks,
Phil.

Try increasing the NB voltage to say 1.55V? And may be change Tref to 54 or 60?

And I would recommend not running more than 2.19V on the ram as the board overvolts the ram by about 0.12V, which makes your current ram voltage to be 2.3V-ish which is definitely not good. You might also need some cooling for your ram.

I personally find this board terrible with ANY memory, when a quad core is used. None of my 5 pairs of DDR2 (two pairs rated for DDR2-1000) will run above DDR2-880. I guess it is just the crap NB. But then you're only using a Q6600 so the strain should be less with a much lower FSB.

Quote:

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Originally Posted by philpem

So what do I need to do, find a RAM speed that's an integer multiple of the FSB (or very close)?

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If you run the ram at 800MHz with the 2.1V voltage and set the Sys Clk 355MHz (1420Mhz FSB) this will clock the CPU to 3.2GHz and RAM to 1066MHz.

Does it work at stock speeds CPU and RAM?

It's fine with the RAM speed at stock (800MHz) and the CPU either stock or overclocked to 3GHz.

Interesting you raise the point about DRAM voltage -- the voltage monitors in the BIOS were all reading around the set points, no noticeable increase/decrease vs the setpoints (no Vdroop or.. whatever the inverse of Vdroop is).

I'll have a play with the timings again later on tonight (starting from my "this almost worked last time" settings), though I can't see it getting much better. CPU 3.2 and RAM 1066 seems like the most likely working solution though...

I miss my nf780i (P5N72T), as shaky and finicky as it was :(

Though this board does seem (electrically) less noisy. If you plugged a set of headphones into the speaker output on the P5N72T, the shrieking and clicking was almost unbearable. Not so bad on external speakers, but a complete pain in the backside when it's 10 at night and you want to play Portal for a bit... The Rampage is almost silent (there's a short click-click-click burst if you start hammering the LAN, but that's it).