First, my system spec: Athlon XP1700+ & TITAN 3200RPM fan+heatsink MSI KT3-Ultra2 mainboard (VIA KT333MHz) 3x512 MB DDR 333MHz CL2.5 (OEM) ATI Radeon 9500 Pro 128MB HDD Maxtor Diamond MAX 80GB 7200rpm CDRW TeacW540 40x12x48 Creative SB Live!Player 5.1 Compex RT10/100TX network adapter (Realtek 8139/810x family) 300W ATX Power supply Case fan some usb devices (UPS control, Logitech Wingman joystick, Pentagram tablet, but not all at once ;-)). In fact, I've two problems :-/, perhaps they're related so I'll describe them both. First problem appeared when I bought new memory for my setup to replace a 256 MB DDR (PC2400). Even the installation was problematic because the setup saw only 1.3GB of mem instead of 1.5GB. Turned out to be a little loose memory bank (at least that's what I think), and after reinserting the mem all was ok (although the problem reappeared a few times when the case was opened to plug/unplug sth.). A few days after installing the memory strange things began to happen. The system was unstable (no that's not windows cache, I've that fixed with Cacheman (www.outertech.com) ;-), and the hdd powered down when I've tried to access the floppy or in some random moments. I've reinstalled the system from a ghost image - no effect. HDD is ok, I've tested it in another setup. My first thought was the power supply but someone suggested testing the memory. So I did that and some strange thins turned out. To make a long story short: all three chips working separate are all ok. Problems arise when all three are plugged in and working at 333MHz. Then - the errors appear (tested with memtest86 (www.memtest86.com) and goldmem (www.goldmemory.cz)). On 266Mhz memory speed the problems didn't appear until recently :(. No tweaking was done to memory. I've even tested it with only floppy, gfx card and cpu fan connected to the powersupply. All else was plugged off / removed. Still errors. Tested it with another 300W power supply (noname), still errors. None of the voltages provided by ps goes into the magical +-10% difference. But when I remove one single RAM chip (doesn't matter which), the problems dissapear. The chips are from the same line, they have consecutive serial numbers (one is 2 numbers farther, but it's still the same series). Now I'm clueless. This could be mainboard, but according to tomshardware (http://www.tomshardware.com/howto/20021021/powersupplies-02.html) the single 128MB DDR-DIMM RAM takes 30 Watts. Now I've 3x512 DDR-DIMM... I repeat - no tweaking was done to the mem, all controlled by SPD. Oh, and the hdd problem dissapeared. No power-downs anymore, perhaps it was a bad plug/wire and after all this plugging/unplugging it got somewhere else? Perhaps this memory problem could be somewhat related to the other problem I've had (and still have) with gfx cards. In my previous setup (MSI KT3-Ultra ARU, which was damaged(?) and was replaced on warranty with the KT3-Ultra2), and ATI Radeon 8500 I've experienced problems with some artifacting on screen. Turned out theoretically to be bad video card (said tech-service), but on the new one the same thing was to see. Now I wonder: from my previous setup, there's only those things left: chassis & PS, CPU, (new) mainboard (which also had problems with the new ATI 8500), sound card, hdd and NIC. Perhaps this is CPU related? Unfortunately the computer was put together from pieces and the warranties expired :/. The same artifacting happens to be on ATI 9500Pro which I'm using now... Power supply? CPU? RAM? AAAAArrrgh :/ Any clues? HELP! :D PS: I know I know - sell this s**t and buy new setup. Unfortunatelly this is impossible due to the size of my wallet ;)

Run a test on your memory.

I did test my memory as written above - with two programs.