I've had an Athlon X2 5800+ (3ghz Socket AM2 Dualcore) in my PC for a couple weeks now. Not the newest of CPUs I could've bought for my motherboard right now, but it was good value for money.
It runs perfectly well as long as you don't max out both cores - it's been running Windows 7 stably the whole time I've had it. However, whenever I play any new games (the kind that max out both cores, e.g. Mafia 2 or GTA 4), I get about 15 minutes of gameplay before the game crashes. Windows continues running stably though.
This is a weird bug, and it could've been to due to memory or my chipset or my drivers, I know - but I found something really odd when I ran Prime95 on the "most heat/voltage consumption" test. It would run two threads - one for each core. After about 5 minutes, the first thread would start throwing 'SUMOUT' errors, indicating the first core was failing to do calculations properly. This would happen when the CPU reached 61 degrees C (according to SpeedFan). Odd thing was that the second core continued to do work without error.
So I decided that, when the CPU hit 60+ degrees, it must get unstable. It would hit this temperature after roughly 15 minutes of gameplay (since games use as much CPU as they can get). What was odd was it cooled down relatively quickly (5 minutes to cool down into the mid-40s, eventually it'd get as low as 33 degrees) after the game crash.
At first I thought it was just a heat transfer issue, since my heatsink didn't feel that warm and I wasn't getting much hot air blowing out of the case. I have one of those big thermaltake/coolermaster fans (can't remember what), for the record - much bigger than the stock cooler. Applied a new layer of thermal paste, CPU runs about 2 degrees cooler and still reaches 61 degrees so still crashes in games. Damn.
The other thing i've noticed is that the design of the fan means it isn't seated snugly over the CPU - one side of the CPU isn't in contact with heatsink, by a couple of millimetres. I can't seem to align it properly, either. Could this be the cause of my 'one core failing' problem?
That said, I didn't think 60 degrees was *too* hot for a CPU, I've seen older Athlons in dusty old machines reach 75+ degrees under load and dealt with it perfectly happily. So could I have bought a processor with one duff core? What's worth replacing - CPU, or heatsink?
Max temp on the X2 Windsor core is between 70 - 72 C. I don't understand how the cpu cooler is on the chip cockeyed. Can you tell us the brand and model of cooler your using. It should fit flush. Did the cooler ome with pre applied paste, or did you apply it?
In any case if cooler is installed correctly with the proper amount of decent compund then I vote for buggard core and would see about an RMA
The cooler is a cooler master fan, similar to this:
except the bottom bit (the bit that keeps it in place on the MoBo) is different. It's a couple years old so I couldn't find the model name/number.
It wasn't flush before, but I managed to adjust it so the heatsink completely covered the CPU. It did help a bit, took longer to reach 60*c once I'd fitted it properly... but it still reached 60*c, and the "one core going faulty" problem still happened.
Sorry, was going to edit that bit out of my post as I'd fixed the heatsink before anyone replied, but it wouldn't let me. Plus it WAS flush before I decided to re-apply thermal paste, so that part of my post was a bit of a red herring.
CPU died on me this morning, so I' m pretty sure it was a case of a faulty CPU, or at least one with temperature tolerances lower than usual. RIP crappy CPU, hello replacement Phenom