by Andy Patrizio
Hobbyists have for years enjoyed squeezing more CPU cycles out of their processor, pushing it as far as possible without melting the whole PC into a pile of slag. AMD has even sponsored overclocking contests, with one group hitting 7GHz back in 2009.
Intel has jumped on this bandwagon, releasing the “K” line of processors that are unlocked and ready for overclockers to do their best. The Core i7-2600K, for example, default to 3.4GHz but can easily be pushed over the 4GHz mark with adequate cooling.
So, is Microsoft going to be a party pooper for the overclocker crowd? A paper published in April 2011 but just bubbling up now would seem to indicate that Windows does not like home-brewed PCs that are overclocked.
According to the Microsoft report, the longer the TACT ? Total Accumulated CPU Time, otherwise known as uptime ?the more likely it is to experience its first crash thanks to a CPU failure. And once it’s crashed once, the chances it will keep crashing due to CPU failure increase.
For example, a PC with five days of runtime had a 1 in 330 chance of crashing, while a PC with an uptime of 30 days had a 1 in 190 chance of crashing. Once a PC crashes, its crash probability rate goes up by a factor of 100 and for a second and third crash.
That statistic goes up if you use a white box/home built PC. Microsoft found brand name PCs had a one in 120 chance of crashing after 30 continuous days versus one in 93 for white boxes machines.
Not surprisingly, overclocking of CPUs also dramatically raises the likelihood of a crash. This is a fact of life for overclockers, who accept it as a hazard of their tinkering. Microsoft Research tested both Intel and AMD chips but obscured them by calling them “vendor A” and “vendor B.”
It’s probably good that Microsoft obscured the names, because vendor B would have a field day rubbing its competition’s nose in these results.
Vendor A’s chips were 19 times more likely to crash after a period of five days of continuous operating than if they were not overclocked, while vendor B’s chips were 4.5 times more likely to crash when overclocked. After five days of non-overclocked use, Vendor A had a 1 in 21 chance of a CPU-related failure, while vendor B had a 1 in 86 chance of CPU failure.
So vendor A was four times as likely to crash even when not overclocked. When overclocked, both vendors ran about even; vendor A had a 1 in 400 chance of crashing, vendor B was 1 in 390.
The research paper goes into depth but it omits a few things known to veteran system builders. First, home builders know that not every piece goes together. Every motherboard maker has an approved list of memory for each motherboard, for example. System builders like Dell and Acer have taken care of this problem and know the best fitting parts.
Second, there were other issues Microsoft didn’t address in the paper. For example, thermal grease, which conducts CPU heat to the CPU cooler, will eventually dry up into almost cement and become useless. This is especially true if you are overclocking. You also need to check your system for dust accumulation clogging fans and vents. Microsoft didn’t discuss the maintenance of systems in its research.
Chris Angelini, worldwide editor-in-chief for Tom’s Hardware Guide, which caters to that crowd, isn’t surprised at the findings – but not alarmed either. “Any time hardware is pushed beyond its stock settings, which vendors put a lot of resources into testing/validating, it should be expected that failure rates will increase,” he notes.
“Of course, it’s possible to counteract some of the negative effects cited. More effective thermal compound, heat sinks, and fans can all help bring the temperatures of overclocked hardware down to more conservative levels, generally improving stability,” he said.
Angelini added he no longer overclocks his main workstation because daytime work is more important than getting a few extra frames out of a game. “Even one crash is too much if I’m not being diligent and saving my work like we’re taught to,” he said.