On Thursday 13 June 2002 23:56, Bockhorst, Roland P HQISEC wrote: > Gentlemen; > Thank you for your help. > My P4 is successfully working on its second 15,000,000 range number. > The first number was found to be not prime in about three months full time. > It should have taken a month, hence this discussion.
Umm. I find my P4 1.8A takes just one week to process a LL test on an exponent just under 15 million. Running 24x7 of course! > > WCPUID recognizes my P4 and its having SSE and SSE2 instructions. > Prime95V22.3 doesn't. This is very odd.... > > >Could the CPU be overheating? > > This is a good idea to pursue. > The P4 thermal slowdown is easy to diagnose - the speed shown by the diagnostic output from Prime95 will vary depending on the ambient temperature. Also, if you stop Prime95, wait a few minutes and continue again (using the Test menu), the CPU will cool down & the diagnostic output will show it starts very fast then slows down over a minute or two as the system warms up again. If you do have this problem, there are now available some very good P4 CPU coolers, and they aren't neccessarily noisier than the standard Intel part. A good tip with Intel "retail pack" CPUs is to carefully remove the thermal goo which is stuck to the bottom of the supplied heatsink - carefully scrape the bulk off with a soft edge e.g. a plastic credit card, NOT a knife which will scratch the heatsink mating surface; then remove the residue with white spirit, then methylated spirit. Allow to dry then apply a good thermal compound like Arctic Silver II in accordance with the instructions on the web site. This will, on its own, reduce the CPU die temperature by around 5C. > > >Win95 unless another SSE/SSE2 ... timesharing > > Good point > > >Surely the problem is that a system with extra registers will use more > > stack > > >when the "save all registers" opcode is executed. If so, the OS need not > >support SSE/SSE2 directly - but there might be a problem with crashing > >through the stack base. > > .... hummmmm the error was "illegal instruction" A stack overflow will usually cause system hang or spontaneous reboot. > ............. I recently bought a new license for Win98. That's fine then. But where from? My understanding is that Win 9x licences are no longer available ... the official MS line seems to be that you can buy a licence for ME or XP Home Edition but install Win 9x provided that the copy of ME or XP HE is not installed on another system simultaneously and on the understanding that MS will do nothing to support you technically. (I believe Windows Update still works with Win 98 but I don't know when the last update to any '98-specific component was posted.) Regards Brian Beesley _________________________________________________________________________ Unsubscribe & list info -- http://www.ndatech.com/mersenne/signup.htm Mersenne Prime FAQ -- http://www.tasam.com/~lrwiman/FAQ-mers
