A7N8X-E Deluxe crashes on boot in nv_agp.sys with > 2GB

[johndog19]

I've been trying to upgrade the RAM in my system to 3GB, so I bought 3 Corsair 1GB sticks and put them in. Any two of the sticks will work fine, but as soon as I put in the 3rd, my system will no longer boot.

The system (Windows) consistently boots up to the point of loading ACPITABL.DAT, but then hangs or reboots at that point. I attached a kernel de-bug-ger and determined that it is crashing in nv_agp.sys, with IRQ_NOT_LESS_OR_EQUAL.

I've tried working with 2 versions of nv_agp.sys, the latest nForce2 driver from the 5.1 install on nvidia, which dates back to 2004 and provides the 4.3.6 version of the "nForce2 AGP Host to PCI Bridge", or the default driver installed by windows, which dates back to 2003. If I delete the nv_agp.sys driver completely (such that I am condemned to vga), the system boots fine with 3GB. As soon as the system installs an AGP bridge driver, though, the crashing returns.

Perhaps it is an address space issue. I've noticed that the bridge takes assignments of every address from 3GB up to 4GB, and that seems risky, depending on how physicall addresses are assigned to the RAM. I've also tried running with 2.25GB, and the same thing happens. Any amount over 2GB causes the crash.

How can anyone have gotten 3GB to work on this motherboard, if nv_agp.sys has sucha limitation? Has anyone gotten 3GB to work with this board? What else can I try?

Note: to boot successfully with the 3GB installed, I merely need to give windows the /MAXMEM=2048 boot switch. Then it uses only 2GB and it works fine. If I give it even as low as /MAXMEM=2070, it crashes.

Any help or information would be greatly appreciated.

Thanks,
John

[_DL_]

Windows uses top 768MB of 4GB address space to address pci devices, so you could install up to 3328MB of ram with no problems (you can in fact install more but the system will not take use of it), but thats how windows works, and it could be an issue with the nvidia agp driver that tries to address some more space for it self.

And it also could be a problem with dual/single channels memory access.

[skinnie]

have you tried 2t command rate?

[humeyboy]

To use 2T he would need a modded bios as its 1T default, AMD are all CPC-ON for NF2's

[andresayang]

I saw on microsoft site a WinXP update solving this error (IRQ.....). Mabe only this patch will solve your problem.