Corsair 4x2GB DDR2 PC2-8500C5
Gainward 8800GT 512mb
300GB HDD @ 7200rpm (Western Digital I believe)
Corsair VX 550W PSU
Windows 7 64-Bit Professional
Firstly, background on the system. Around 3 months ago I upgraded to 4X2GB of corsair XMS2 1066 RAM as I work with 3d rendering and found myself frustrated with only 2GB of crucial RAM. I was not aware at the time this particular gigabyte board seemed to have problems with RAM above DDR2 clocked at 800mhz so after soaking up info from around the web I managed to get the 4 sticks stable by downlocking to DDR2 800, upping the voltage to the 2.1V specified on the module and manually setting CAS timing.
Now for my current issue, 3 days ago the power cable running to my PSU was knocked and the desktop lost all power. Something similar had happened a couple times in the past with random power outages so I hit the power button expecting everything to be fine. Of course as you may have guessed, they're not The computer appeared to be stuck in a perpetual boot cycle with nothing being displayed on the monitor and the desktop would restart after roughly 8 seconds everytime. It seemed almost certain to me that my video card had been damaged so I swapped it out for the 6800GT from my old build but experienced the same problem.
At this point I removed the CMOS battery to reset the config and the display worked fine again. I then reset my BIOS settings to as I had them before and all appeared fine until 3 minutes after booting into Windows when the screen went blank and the monitor showed a "no display" message which, again, seemed to point to a problem with the video card. I restarted once more however and whilst booting Windows it threw a BSOD and started to dump physical memory which told me the RAM was having issues. I removed 3 of the sticks leaving just 2gb and reset the BIOS to gigabyte's optimised defaults, saved the settings and proceeded to restart. Just after booting into Windows however I experienced the same blank screen and no display message. At this point I was worried that the RAM had been damaged rather than the video card so I tested each of the 4 modules singularly using the Windows 7 memory diagnostics tool, none returned any errors whatsoever. I then tested them two at a time, using different slots, and they all still appeared fine with no errors. Just to make sure however I replaced the RAM with 2X512mb of old Corsair DDR2 800mhz Value RAM and the system appeared stable for slightly longer before throwing the same blank screen and no display message.
After all this I've come to the conclusion that something is the matter with my motherboard but I'm by no means an expert at this, just someone that's pretty good at reading Thanks in advance for taking the time to sift through all this, any feedback is appreciated.
My thanks for the replies gents! Status update now: Firstly the 8800GT is running fine on this older desktop after installing the latest nvidia drivers which is great! Also hooked up the Corsair PSU to test and everything is stable (am currently composing this on the spare desktop with both parts running.) I'm quietly happy with these results since I've never been pleased about having to underclock RAM in order to successfully boot.
So the question I now put to you is would it be worth it to simply purchase a new Socket 775 board (I'm looking at the EP45-UD3P) and try my hand at overclocking the CPU in the meantime, or perhaps take this time to spring for an upgrade with new CPU, motherboard and then a new video card later in the year. I'm rather out of date on the state of affairs with current processors so any ideas would be fantastic. Many thanks!
First thing to do is to run MemTest86+ on one stick at a time to check physical condition: MemTest download/prep instructions (have choice of bootable CD, floppy, or USB stck) about at the middle of Memory Part IV - "Tweaking and tuning"; stick testing procedure toward the bottom...
I am somewhat amazed it actually worked at one time! Typically, info on the DIMM's SPD is set up for one DIMM per channel - needs 'tweaking' to handle two... For four sticks on 775s, this typically amounts to: put two sticks in, do the Load Optimized to set 1066 parameters; take MCH voltage up a tenth volt; add 15% (rounded up to nearest integer) to whatever LoadOpt set the tRFC at; might need to bump memory voltage itself a half-tenth - best thing is to do it first, test, then lower it back to see if it keeps working; double check that memory command rate is set to '2T' or '2' - however your BIOS shows it; make sure that the "MB Intelligent Tweaker(M.I.T.)" page's DRAM "Performance Enhance" is set to "Standard"... <F10> to save, exit, and reboot - then, power down and add other two sticks.
Another thing to be aware of is that with four sticks of fast RAM, you are actually both overclocking and overvolting the memory controller hub (MCH); definitely need good case airflow - and never hurts to thow some active cooling on the MCH itself:
Thank you very much for the comprehensive advice Bilbat! It's certainly appreciated, I will bear this in mind for the future and test the RAM tonight. However I've already tested 2 older Corsair Value DDR2 sticks (800mhz I believe) and the Crucial RAM I had before upgrading in the system, trying both single and dual stick configs. I'm confident this is an issue with my motherboard now so as before I'm wondering whether this would be a time to upgrade or not
If you'd like, I can (hopefully ) give you a set of board parameters for mild OCing/maximizing RAM stability and speed. I don't have an existing set for that particular board, but I do have about fifteen existing 'canned' sets that have worked - shouldn't be much effort to adjust one for your board...
Nearly everyone who knows me knows I'm 'some kind of computer geek', and are always asking me the 'upgrade now?' question. I always laugh and tell them - "now's as good a time as any - no matter what you buy, no matter what you spend, when you pull the tape off the box, you can pretty much depend on it being obsolete!" I saw this years ago, and it's never become outdated: "good today, junk tomorrow and worthless next week in the never ending circle of the pc hardware bottomless money pit of losing value!"