The first bizarre point is that the BSoDs have a lot of variety. Sometimes it's IRQL_NOT_EQUAL, sometimes' it complains about the nvidia driver, sometimes it's a memory dump or a system exception. My computer can run for a few days until the blue screen, or it can happen multiple times in one day.
The second bizarre point is after boot. If my computer has been off for awhile and I boot up, it's unstable for the first 20 minutes or so. If I dare to open a browser, it may let me click on a web page, but it'll promptly crash the browser. Same if i start up a chat client. If I push it too much, there's a very low threshold -- the computer will promptly BSoD. Now, if I leave the computer alone for 20 minutes after boot, it'll be stable for long periods of time no matter what I do.
The third bizarre point are game crashes. Playing Team Fortress 2, or I think any Source engine game, It'll occasioanlly get the sound crash bug, other times it'll give me a 'cannot read memory' crash error box. It happens perhaps once or twice at first; other times I can go an hour or two no problem. Starcraft II has a bit of instability as well. Sometimes it'll lock up, and then a few seconds later, close itself and give me an error (and blizzard will ask me to submit a report). I can also, at any time, blue screen during gameplay of any game. I could even blue screen while simply watching a video or opening a folder or using an internet browser to watch a flash vid, etc. Pretty benign stuff. TF2 and Starcraft II crash fairly regularly, though. I cannot be depended on to last an entire SC2 multiplayer game. It can happen, sure, but there's always a risk of me crashing out.
So these are pretty weird occurences. Surely something is failing or about to die, but I've been ignoring it for months now and the death hasnt taken place yet. I am seriously considering purchasing SC2 now (using the guest pass till then), but there's no point if I can't reliably last an entire multiplayer match, so it's time for me to figure out what's wrong.
So has anyone any ideas what could be failing that could lead to such odd symptoms? I'm running Windows XP. It's been a year and a half since I installed any new hardware. At the time, it was a Seagate Barracuda 1TB Drive that is now my boot drive, and an additional DDR400 RAM module. Yes, not exactly the most advance tech, the mobo/proc are 4 or 5 years old now (AMD X2 4400+). Thanks in advance.
Being so random, I would be looking at your RAM. You say there is more than one mem card... take one out, and try the different cards. Look at mem timing, it's only going to go as fast as the slowest card
If you mixed high density and low density boards, and/or hi and low density chips, (yea, it gets crazy), then problems come along with address matrix situations.
I'm just curious, but how did you pinpoint the 2 RAM chips as bad? Did you run memtest on them? As Tigsounds mentioned, you may just need to manually adjust the RAM timings to get them running the same.
I ran a memtest program. It always found fault with the OCZ chips. I tried a variety of combinations -- just the OCZ chips, just the G-force chips, combinations thereof, etc. etc., it always found errors whenever OCZ chips were in the system (exclusively or combined with g-force) and showed typical instability.