Can't load Windows on GA-7N400S with more 2GB RAM

[MasterGammy]

CPU AthlonXP 2800+ Barton rev.A2, I have 3 modules Hynix DDR400 1GB and Hynix 512MB.
When installed 1GB + 1GB all works normally, but with 1GB+1GB+512MB  or 1GBx3 I have reboot or BSOD when loading Win7,Vista etc.
WindowsXP SP3 can load normal with 2.5 GB RAM.
FSB 166, overclocking disable, reduce timings can't fix this problem.
Motheboard must support 3GB or not??

[MisterEd]

I originally built a system in November 2002:
Motherboard: ASUS A7N8X Deluxe v0.6
CPU: Athlon XP 2800+ Thoroughbred
RAM: 1GB (2 x 512MB). No kits back then.
O/S: Windows XP Professional

A lot of people had problems with motherboards with the nForce2 chipset back then because it was real picky with RAM. There were no RAM kits back then so I had to buy good memory and hope for the best.

I had problems with the original motherboard so I replaced it a few years later.
This is the current configuration:
Motherboard: A7N8X-E Deluxe v1.0
CPU: Athlon XP 2800+ Thoroughbred
RAM: 2GB Kit (2 x 1GB)
O/S: Windows 7 Home Premium

I was curious about your problem with 3 sticks of RAM so I decided to add a 3rd stick of RAM to see if I could get it to work. I used one of the original 512MB sticks of RAM I bought 11 years ago. I knew I would have a problem since the 512MB RAM was DDR333 while the newer 1GB RAM was DDR400.

The system crashed with the new RAM. Through experimentation (including a few BIOS resets) I finally found a combination of manual settings that worked. I used Memtest86+ to verify initial stability. I used Prime95 for over 1 hour to further prove stability.

The image I inserted shows the RAM I used, the sockets in the motherboard I placed the 3 sticks in, the BIOS changes I made for the RAM timings, and the results from CPU-Z.

Note that I changed the timings to match the JDEC #1 configuration for the 512MB stick. Also note the 2 sticks of 1GB RAM had to be slowed down to match the 512MB RAM speed.

I do not know if what I did will help you but at least it proves that 3 sticks of RAM will work in these boards. BTW, it would have been a lot less of a problem if all 3 sticks were identical. Since we are both mixing RAM that made things more complicated.

[MisterEd]

Update:
I had to return the system to 2GB (2x1GB). It seemed to work ok at first with 2.5GB  (1x512MB+2x1GB) but has since become unstable.

Sometime in the future I may try this again. This motherboard should work with 3 sticks of RAM. I would like to verify that all 3 memory sticks have to be identical for this to work. Unfortunately I do not have 3 sticks of identical RAM to test this.

[Vezina]

More sticks less speed should be used and 2T.
My KT333 based board was running just fine with 2 Gigs of RAM and Windows 7 and an Nvidia 7600GS video card.