question, I want to upgrade the memory on my motherbord Intel E7525 dual Xeon,
whats the max memory config I can install, knowing that I'll install Win7 64bit ?
I now have 3GB Corsair DDR2-400 (2x 1GB + 2x 256): because WinXP Prof was limited to 3GB.
But with Win7, what's my max upgrade in memorypossible for my motherboard ?
Sorry, the most I could locate is that your motherboard is an Alienware exclusive '[MJ-12] X2 7525 Dual Xeon'.
Also unfortunate is that they do not have any XP x64, Vista or Windows 7 drivers available, meaning you are limited to a 32bit OS regardless.
Maybe you should try contacting Alienware Support directly to see what they can do for you.
TBH though, your system is very dated and probably not worth throwing cash into.
For not to much more than the ECC DDR2 RAM upgrade on your current system you could get a new, much better performing Motherboard, CPU and standard DDR2/3 RAM.
I had the same problem with the same Alienware model a while ago, but I found a way around in order to upgrade the system to win7 64bit so that I could expand the memory.
It took me about a month to gather all the info about the motherboard, and at first I also believed that my X2 mobo was an Alienware exclusive, but a careful research proved me wrong. I have to say that I tried Alienware support, but since my X2 workstation is quite old, they were not too helpful, to put it mildly.
The Alienware 7525 dual Xeon motherboard was manufactured by Iwill, and it was marketed under the name Iwill DN800-SLI, it supports up to 8GB ram in four 2GB ECC registered DDR2-400. If you decide to expand that memory make sure to get 400mhz RAM, because Win7 won't work with any other RAM frequency in that motherboard.
The total cost for the 8GB RAM was a bit short from $320.00
You'll need to flash the BIOS at least to version 1.11 so that you can configure your hd for setting up a 64bit system, and you can find the drivers for the chipset at the Intel site.
That having been said, I must warn you about an issue with the audio that I haven't been able to fix yet. I installed a generic AC'97 driver for the integrated audio, and windows seems to recognize it, plus I get a graphic view of the signal volume, but there's no output at the speakers. I still don't know for sure whether that's due to a problem with the header cable or if that's a system issue. However in my case it doesn't matter much because i only wanted to upgrade that old workstation in order to add it to a render farm, so that for now I can live without audio in that computer. Yet I'd be quite happy to hear about a fix for that problem if you find one.