I bought a new G31M-ES2L, Intel Core Duo E5200 CPU, Corsair Twin2x4096-6400C5C DDR2 RAM and a 9400 GT graphics card. It's my first Gigabyte, but it's not making me happy.
Everything seemed all right initially:memtest86+ 2.11 passed without error, a live Linux CD work well, booting from HD works well (except that Windows XP jams, but apparently that is normal for a new motherboard). But when accessing large files, I run into md5 or crc errors, and strange things happen in XP including BSOD. In Linux, comparing different copies of the same file shows the difference is a single bit failure, apparently always in the 5th or 4th bit of a byte, at locations scattered over the file (about 1 bit every 20MB). Which reminds me of a similar unreliability I had 10 years ago when copying from the network, caused by dirty contacts of the PCI network card.
Naturally I cursed, reseated and replaced the IDE cable, tried with only the HD or DVD connected, all to no avail. I copied files to a ramdisk and ran md5sum repeatedly: unstable results. Sometimes md5sum yields a deviant result but the next run the original md5 is back. So it doesn't seem like memory itself is unstable, it's the reading of memory that is unreliable. Or the processing by Mr. Gigabyte himself. Or the CPU.
Reseating the memory modules doesn't help. What does help is yanking out one of the memory modules, putting the system in single channel mode. Testing md5sum in a 1GiB ramdisk seems stable now, with either of the 2 memory modules. But checking md5sums from a DVD yields intermittent errors. All thosefiles are cached in RAM - the DVD doesn't spin at all. So my guess is that the 1GiB ramdisk gets allocated in a better part of RAM and the file cache elsewhere.
The RAM I have is not listed on the certified memory list for the motherboard - only 2x1GiB versions are listed. I don't need 4GiB, but less was simply not for sale. However if the RAM is to blame, why doesn't memtest86+ find anything after running for 10 hours? Any other tests I could run?
The PSU is a Silverstone 300 Watt, which I trust because it was expensive and power consumption measured at the plug is now at most 85W(cos phi = 0.85) while the previous motherboard used to peak at 150W, without exhibiting any instability. I haven't touched the graphics card - come on, this can't interfere while a silent command line test runs?
