hp xw9400 will not boot with more the 8gb of ram

[Tamikanottammy]

I cannot seem to boot my custom build with more than 8gb of ram. my mobo is a xw9400 hp workstation. I tried two of the exact same board and had the exact same issue with both. I try with 8gb (2x2gb) and it works runs no issues. add even as much as one more module and it des the following:

powers on
detects the amount of ram installed
1-whatever

when it gets to about 4gb ish it shuts off


whats going on here?? anyone??

 

[Barty1884]

Which xw9400 variant?

Which RAM modules? I assume this is not a matching retail "kit" (ie modules sold together)? "Mixing and Matching" RAM can be problematic. Without knowing exactly what you're trying to use, it's really tough to help diagnose.

 

[Tamikanottammy]

how do I tell the variant? and I tried ram sold together yes. idk if they originally came together but I believe they do.

 

[Barty1884]

What are you components?

 

[Tamikanottammy]

I tried two builds a build with a quad core 2378 opteron 8gb ecc quadro 600 and


And a hexacore build with dual 2431s 8gb ecc and a FirePro 128mb

Any suggestions??

What are you components?

 

[Tamikanottammy]

i switched my cpus and gpu and os

i now have

2x 2431 quad core opterons
250gb sata hdd
windows server 2008 r2 working 100% so far (even though the board was not designed for it i know i know)
nvidia quadro 600

and of course

the dumb 8gb ram!

what am i doing wrong?

it STILL wont boot with more than 8gb! i know the board was made to handle something like 32gb! I tried every config two kits and 4 individually bought 4gb modules!

what's going wrong?!?!