On 14 Jan 2002, at 14:45, Steve Elias wrote: > 1 - i just got my wife's toshiba laptop back from toshiba warranty > service. running prime95 for ~6 months on it caused the fan to die, > and then the laptop would overheat & shutdown even without prime95 > running. apparently the heat caused lots of disk badblocks too.
I've had a Tosh Sat 4070 laptop running mprime 24x7 for about 3 years. The fan runs - constantly. A fan certainly shouldn't die within one year, though some will undoubtedly do so, due to manufacturing faults. As for bad blocks on disk - I wouldn't trust a diagnosis made on a system with a cooked processor. Even if the disk has developed read problems on some blocks written when its temperature was way too high, reformatting (or block repairing, using a suitable utility) the disk when it's running properly cooled should repair them. > > 2 - my manager at work here had a thinkpad. he ran prime95 despite my > worry that it was very "tough" on laptops. within a few months his > harddrive failed - possibly due to months of excess heat... :| this > could be considered a classic Dilbertian CLM (career limiting move) on > my part, but no worry since my manager is super-cool. Blame power management. HDDs constantly starting & stopping are going to age rapidly. Prime95 helps accelerate this process by writing save files every so often. Changing the disk write time to 1 hour or so seems reasonable on a laptop since the main reason you write save files is to protect against power loss; all laptops effectively contain a UPS, and should suspend without data loss even if the battery runs flat. I'd reccomend: (a) configuring power management to run the hard disk constantly when the system is on mains power, to extend the disk life; (b) configuring Prime95 to suspend itself when the system is running on battery power. This reduces HD start/stop activity and extends the usable run time by allowing the floating-point unit to shut down, reducing both power consumption and the cooling requirements considerably. > > 3 - i also ran the prime95 app for a year or so on an ancient cyrix > p120+ which had a cpu-fan that stopped. after a couple months of > no-cpu-fan, that cpu died completely... No surprise at all. Undercooled processors will die sooner rather than later, whatever you run on them. Meanwhile they're probably not running reliably, so whatever data you are processing aren't reliable. > > 4 - i bought a 2Ghz P4 recently. despite initial worries that it was > running too hot (70 C) because fan was too slow (2800 rpm), i got > adventurous and clocked the cpu at 2.1 Ghz for a day. weeks later the > machine started acting very badly (motherboard cpu temp alarm caused > shutdown @ 90 C even without prime95 running). so i returned it to > the vendor. they claimed that my overclocking it broke the P4, and > that the top of the cpu was actually burnt/blackened from the heat. > this is counter to my belief that improper fan/heatsink was the cause, > but i can't prove it. also it runs counter to what i've read here & > elsewhere about the thermal-protection built into P4s 1.7Ghz or > faster. they are returning the P4 to intel to see if Intel will > replace it for free, but in the meantime i have to pay for a new cpu! > (i'm picking 1.8Ghz this time.) Again it's no surprise that, if you overclock a CPU and fail to uprate the cooling, the processor will run hot. The existing 0.18 micron 2.0 GHz P4 is pretty close to the limit of what can be done in the way of transporting heat out of the die (that's why Intel are shifting to 0.13 micron technology). Experience in the past has always been that the low-end chips in any particular family stand overclocking better than the high-end chips, though I'd be very surprised to find a x GHz rated chip overclocked to 1.2x GHz performing more stably than a 1.2x GHz rated chip of the same type. Intel's warranty seems to state very clearly that the warranty only applies to chips operated within the stated limits, so failure to honour a warranty claim on an overclocked CPU would be quite reasonable. Intel "retail box" processors use a larger than normal fan, so a slower rotational speed is reasonable & will shift the same amount of air. The reason this is done is that aerodynamic fan noise depends on a large power of the air speed, so moving a larger slug of air more slowly is quieter than moving a smaller slug of air more quickly. 70C sounds too hot to me. But I don't know the exact way in which the sensor is incorporated into the P4 die. There should be a document on the Intel site showing the thermal constraints for each variant of the P4. Motherboard at 90C is undoubtedly fatal! Was this really due to a processor cooling problem, or is there a runaway voltage regulator? (You didn't overload the voltage regulator during your overclocking experiments...?) BTW it's fairly common for thermal tape or cheap thermal paste to crack and/or darken after a period of use. Personally I use and reccomend "Arctic Silver II" thermal compound, which is stable at temperatures up to 150C (If it ever gets that hot, your CPU will undoubtedly be destroyed). > > so far my count is "4" for computers i've damaged with the help of the > the prime95 application. but i'll keep running it because it is the > coolest application around (in a hot way). Blaming Prime95 for these problems is a bit like blaming your gasoline supplier for punctures caused by driving over beds of nails. Regards Brian Beesley _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
