3GB RAM with nForce2 A7N8X

[Lev]

I've had major problems trying to get a third stick of RAM to work in my nForce2 A7N8X V2.00. 2GB runs great, if I add in third 1GB stick to give 3GB total, things get unstable in XP. Vista and Win7 RC won't even boot, they'll just blue screen.

After a week of searching and experimenting, I finally got it stable in XP, I haven't tried Vista or Win7 with this yet.

Here's what I found:

1 - You must set the AGP Apperature to 256MB for the BIOS to see the full 3GB. If you have it set to 512MB, the bios will only see 2.5GB. From what I've read, this is because the 32-bit address space isn't large enough for that 512MB AGP mapping.

2 - Now that the bios can see 3GB, next is getting XP to boot and be stable. I've seen everything from blue screens, to games just crashing to desktop and random reboots. All the research I found tended to point towards 200Mhz not being a stable FSB for three memory dimms. So this is where I had to sacrifice some cpu speed for the extra memory. I was running 200Mhz @ 12x = 2.4Ghz and that crashed all the time. Instead I now run 184 @ 12.5x = 2.3 Ghz and everything is stable.

[Gilly]

nice to know people still use the old (and maybe nv's best? ) hardware.

glad you got it working

[Phrak]

Hi, Long-time lurker here...

Cheers for the info. I found your original discussions over at vistax64.org

Just a slight addition to what you've found, I couldn't even get the BIOS to recognise the full RAM capacity unless my AGP aperature size was set to 128MB. There was no change in detected RAM if I dropped this value lower.

When I had the AGP-Aperature size at 512, detected RAM was 2.3GB.
When APG-A at 256, detected RAM was 2.8GB

Running 3x DDR400 sticks 10x200 speed, 2.6V - A7N8X-Deluxe R2.0, 1008 Uber BIOS

Hope this helps others.
Tim