Re: Mersenne: Update on using Prime95 as a windows shell
Don't think I didn't try this (and a number of similar ideas). The problem was that the forked copy of Prime95 doesn't seem to start executing until ReCache completes. Either that or ReCache suspends itself until Prime95 completes - *most* unsatisfactory to hog all that memory long-term... That's interesting; I haven't been getting that problem. When pass 2b starts, Prime95 launches, and ReCache continues until the pass finishes, and then it terminates, leaving Prime95 running at peak performance. I'm running Windows 98, and I compiled your code with Borland C++ Builder 4. Could one of these factors make a difference? (If you're interested in trying out my compiled executable, I'd be glad to send it to you.) As you've found out, running ReCache to completion then starting Prime95 does have a good effect (it forces DLLs etc. which aren't currently active to be dumped, for a start). However, I certainly get more consistent results using the manual start procedure. The automatic method has been completely consistent for me. Strange... ___ Get Free Email and Do More On The Web. Visit http://www.msn.com Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm
Mersenne: Update on using Prime95 as a windows shell
Thanks for the responses to my suggestion on this topic. Brian Beesley's ReCache code was very helpful. It doesn't lower the best possible iteration time attainable on my machine, but it does provide a reliable way to get it. In fact, I found that there is only a marginal difference between the performance of ReCache+Prime95 under the Explorer GUI versus using Prime95 as a system shell. With the former, my pII-400 gets 0.188sec/iteration on an exponent around 6.39 million (320K FFT); with the later, it gets either 0.188 or 0.187 sec/iter. I made one small but useful enhancement to Brian's code: at the beginning of pass 2b, I added a call to the system() function using argv[2] as the argument. This saves the user from having to manually start Prime95 at the precise moment that Brian specified. On my desktop I have a shortcut with the command line c:\stuff\recache 64 c:\stuff\prime\prime95.exe which starts prime95 using the modified ReCache program. Now when I leave my computer for the day or go to bed, I can close Prime95 and then restart it with this shortcut in order to insure optimal performance while I'm gone. ___ Get Free Email and Do More On The Web. Visit http://www.msn.com Unsubscribe list info -- http://www.scruz.net/~luke/signup.htm
