Vista - 4GB Issue with Vista 64 HP New Build

Hi all,
This is my first post as a new member so please forgive me if this is not an appropriate thread.
My problem is that I have recently built a new rig with vista 64 HP as the O/S but cant seem to get it to stabilise with 4 Gigs of memory. The system is fine with 2 and 3 Gigs but becomes unstable with 4 Gigs when running process hungry applications such as COD 4. The game will freeze and if I drop out through task manager the screen is then full of graphical glitches.

Below is the details of my current build;

Motherboard: Gigabyte GA-EP35C-DS3R.
CPU: Intel Quad Core Q6450
CPU Cooler: Pro 7 freezer
RAM: (4 x 1024) OCZ SLI Ready DDR2 PC-8500 1066MHz.
GPU: XFX GeForce 8800GTS 500M 640MB GDDR3, PCI-Express.

I have changed the RAM several times and after the system has become unstable I have had it tested and it wasnt corrupted.

First try was, OCZ 4 Gig Kit (2x2048).
Second try was, Corsair 4 Gig Kit (2x2048).
Not sure if one of the Motherboard RAM Module Channels may be at fault as I have had a lot more success with 1 Gig sticks.

Hope someone can help or knows of a fix with Vista 64 HP.


Thanks YoSS,
Oh also loving this site for tips and work rounds with vista.

Have you tried updating the bios?

You might want to check you see if your power supply will run your card. It need to supply a fair amount of current on the 12v rails. Also you might want to make sure you have good case ventilation....

BIOS has been updated and I am running a 750 watt power supply. I've a new case wit lots of space, several 120mm fans and loads of ventilation.
Thanks for the advice. I am still wondering if anyone else has had a similar issue.

Well as discussed on another thread, all power supplies are not the same. That beast of a video card you got would need to have good current ratings on the 12 v rails. COD4 is more video card intensive than anything. If you card draws more current than the power supply can deliver.....crash city

Hi

Check in your BIOS, probably under the NorthBridge chipset setup, for an option called "Memory Remapping", and Enable it if you have that option.
Any overlapped memory (usually Video memory mapping) will be remapped and this could very well solve your issue.
The way this sounds since it's fine with less than 4G's, is that there is a memory stack instability caused by improper mapping possibly.
Memory Remap is a feature designed EXCLUSIVELY for 64bit systems, so if any 32bit users read this and have Memory Remap enabled in their BIOS, disable it. Some forums and less knowledgeable users have told newbies with 32bit systems to Enable that feature but it isn't designed to be used in conjunction with a 32bit system.

Had to throw that in JIC..

Thanks again chaps for the advice.
I dont think I have any power issues as previously stated the system can handle any application with either 2 or 3 Gigs of memory installed. It's just when I try to get 4 Gigs to run that it becomes unstable.
Chappy, I will dig deeper into the BIOS settings, but remapping hasnt as yet jumped out at me. (wondering if it could be named under something else, as there is alot of DRAM timing settings which I am quite reluctant to tamper with just yet).
Thanks Chappy, I will keep you posted with my endeavours. It sounds like you have hit the nail on the head, now I just have to find it.
Cheers.