On Tuesday 22 March 2005 21:54, GANNS.com wrote: > Not that I have much to add, but I can confirm how sensitive Prime95 can > be. I had overclocked a previous system and was pleased that all of my > business and entertainment software appeared to function normally, but then > Prime95 would give *some* error and quit calculating *some* stage. Clocking > back to the proper frequency satisfied Prime95, so I left things alone,
Quite sensible. In fact it's usually possible to get away with a few percent overclocking, especially if you keep the temperatures on the low side. I'd reccomend starting with about 10% over; if it doesn't boot reduce by 2% at a time until it boots; then reduce 1% at a time until Prime95 runs stably, _then reduce 1% more_. If Prime95 runs stably at 10% over, try 20%... :) > assuming that if Prime95 detected problems, then worse could be the > *undetected* problems with my data down the road. Yes! I'd also reccomend fitting ECC memory (if your system supports it) as this will more or less eliminate the effect of random memory glitches. There is a small cost penalty but a stable, reliable system makes much fewer demands on the operator's sanity, quite apart from saving time rebuilding systems after crashes. > > http://GANNS.com > Games, Science, Technology, Humor > Tell your friends about GANNS.com or I will cut you in the face. Ho, ho, very satirical. Actually this is a threat of violence which, in some administrations, is in itself a jailable criminal offence. > > [mailto:[EMAIL PROTECTED] On Behalf Of Jeremy Blosser > > Sent: Tuesday, March 22, 2005 1:16 PM > > > > Since Prime95 is a processor intensive task, it can easily > > make system errors show up due to overheating. Prime95 is > > used a lot by overclockers to test their systems when they > > increase the chip speed. I'd hazard a guess that the errors > > you guys saw were due to Prime95 taxing your system so much > > that somewhere along the way the disk drivers wrote some bad > > data out to the HD. Or simply the system glitched (most likely memory) in such a way that the disk system did a reset whilst data was still flowing from the drivers - thus corrupting the boot sector. Or the HD overheated - extra current consumption due to working the system hard causes a rise in temperatures throughout the system. Not all systems have good air flow round the HD. > > > > What is odd is that most antivirus programs will catch if a > > program tries to write to the boot sector, so if you had one > > running at the time you were running Prime95, I'd be fairly > > certain that the cause is faulty hardware that is showing up > > when Prime95 runs just because Prime95 is taxing your system > > to the point that the hardware errors show up. I agree entirely. Note in particular that configuring RAID - even in mirroring configuration - is no protection against data loss resulting from software errors, or from hardware glitches or failures except when these are internal to one of the disk drives. There is simply no shortcut to a sensible backup strategy. > > > > I'd be interested to see if you run some other CPU crunching > > program and see if the same behavior manifests itself. memtest86 is a good CPU heater / memory thrasher that doesn't use the HD system at all, in fact you can boot it from a floppy (or CDROM, or presumably a bootable USB pen drive) without a HD connected. > > > > Tom Duda wrote: > > > Hello > > > > > told, this phase is the most RAM-intensive part of the > > operations of Prime95. What I did not expect was that the > > boot sector of my system partition became corrupted. I first > > permitted Prime95 to remain installed; I booted to the > > Recovery Console (installed on my machine as a boot-time > > option) and typed FIXBOOT. The system partition was repaired. BACKUP, BACKUP, BACKUP. The sensible way to do this is to temporarily install an extra disk, boot tomsrtbt from a floppy and use the dd command to copy the whole drive to the spare: dd if=/dev/hda of=/dev/hdb To repair damage just swap "a" and "b" in the above line. The spare disk can remain in the machine, just disconnect its power & ribbon cables so it can't be damaged by software glitches, virus activity, etc, etc. This is as quick and cheap as rebuilding a mirrored RAID system after a disk failure and eliminates the chances of losing data to everything _except operator action_. Unfortunately you don't get the performance gain that RAID mirroring will give you but nothing comes for free! > > > > > Something corrupted my boot sector. By coincidence, the corruption > > > > happened on the same day that Prime95 began primality > > testing. By similar coincidence, the corruption stopped when > > Prime95 was uninstalled. hmmmmm. Prime95 does all its I/O through the operating system. It is a well behaved program from this point of view. If running Prime95 damages your system, it is at best marginally stable even without stressing it. Lots of us are running Prime95 (and/or mprime) through many versions for several years and have simply not witnessed the sorts of problems you report. I suggest strongly that you fix your system problems - improve the cooling, reduce the CPU speed (especially if overclocked), replace broken northbridge cooling fan?, increase timing on memory or replace memory with higher specification, ... Regards Brian Beesley _______________________________________________ Prime mailing list [email protected] http://hogranch.com/mailman/listinfo/prime
