In my case, it wasn't the fins that fouled the memory, it was the fan. I tried relocating the fan on the cooler, but that just left too many fins with no air flow. Perhaps if I'd used more conventionally shaped memory instead of Corsair DHX it would have fitted, but then I would have ended up with a cool processor and hot memory, which is just as bad as both being on the warm side. When I get chance I'll start looking for another cooler, but I have to say I'm impressed with the stock unit supplied with the Phenom II 955BE. Its a fairly substantial alloy unit cast onto a copper contact base with lots of closely spaced fins and four heat pipes carrying heat from the copper contact base to the outer end of the fins so that the maximum amount of cooling is built into its very modest size. With the processor under a fair load at stock speeds it still keeps the CPU down below 45°C, and that's with the fan set to max speed only when the CPU reaches 55°C. OK, it probably doesn't leave a lot of scope for heavy overclocking, but for stock speeds and mild overclocking it should do the job nicely. And I'm more than happy to keep using it until I can find a cooler that fits in the space I've got.
Where I have a bigger problem is keeping the 'system' temperature down. On the board I've got (MA790FXT-UD5P) the voltage regulators, north and south bridges are linked by heat pipes and each has a finned heat sink. The south bridge heat sink is pretty flat and doesn't lend itself to natural airflow cooling, but it doesn't get that hot. The north bridge and voltage regulator heat sinks are much larger and more finned, but to me the fins run the wrong way and they are capped with fancy covers, meaning they probably aren't as effective as they should be. Also, with the north bridge being in the middle of the heat pipe sistem with no direct airflow to it, it gets hot. From what I've seen I'm assuming the system temperature is measured at this point. Having seen the system temperature hit 45°C with the system idle whilst the CPU is at a lower temperature I decided something needed to be done, so at the moment I have a small fan (40mm) sitting on the video card blowing air towards the north bridge heat sink at a slight angle. It moves very little air, but has knocked a good 10-15°C off the system temperature, which suggests the heat sink design isn't that good (since when have horizontal fins been a good idea for cooling without a fan?) and has acutally been selected more for looks than performance, and I find that a little worrying. If a board is designed as a high end board with overclocking in mind it would be reasonable to expect the standard chipset cooling to be pretty good, but in actual fact it seems to be pretty mediocre. I would therefore suggest that anyone looking at upgrading their CPU cooling also looks at the chipset even if all they do is add a fan in the case to move air across the existing heat sinks.
Like Pete, I suspect many electronics failures are due more to sudden temperature changes than extreme temperatures. Much of the equipment I us at work (building and heating controllers) is rated for 40°C ambient temperatures or higher. I know of many controllers that are now 15 years old or more that have been running almost constantly over that time in temperatures above 35°C that are as good today as they were when new, except for the discolouration due to being in these high temperatures for prolonged periods. Most of these controllers use 8 bit Motorolla processors which aren't particularly powerful, but equally they don't have any form of heat sink. More modern controllers use 32bit Motorolla processors, but again don't have heat sinks, and they survive these high temperatures. I also know of several PCs (from original Pentium right through to P4) where the CPU cooling fan and even the power supply fan has stopped causing the CPU to get hot enough to crash the PC, but a change of fan and PSU (as required) has seen these computers working faultlessley again for years. In fact, I don't believe I've come across a PC that has had a CPU failure. Most get 'retired' through hard drive failures, fan failures or physical damage that isn't cost effective to repair. One thing they all have in common is they run more or less 24/7 with a fairly constant processor load meaning the components are rarely subjected to sudden changes of temperature.
Extending this to home PCs that tend to be switched on and off or have wildly varying processor loads, both of which cause temperatures to fluctuate, it is probably better to have the cooling fan(s) speed controlled on temperature to reduce the fluctuations instead of keeping the fans running flat out. With the fan flat out, the CPU will tend to cool rapidly when it goes from high to low load whereas a temperature controlled fan will tend to cool the CPU much less and more slowly. Also, when the load increases, with a fixed speed fan the CPU temperature will rise rapidly, whereas a temperature controlled fan will mean a slower, smaller rise. The peak temperatures with a fixes speed fan will probably be lower, but if its a temperature change that does the damage that isn't really relevant. I know most overclockers tend to run with fixed speed fans, but perhaps here there is also a case for temperature controlling the fan, the only real difference being that the temperature when idle on an overclocked system would probably need to be set higher than on a standard system so that when the CPU goes under load the temperature change is kept to a minimum.
