mersenneforum.org  

Go Back   mersenneforum.org > Great Internet Mersenne Prime Search > Hardware

Closed Thread
 
Thread Tools
Old 2004-08-23, 00:34   #1
Doorbasher
 
Aug 2004

22×3 Posts
Default Really slow machines?

Hey evryone.

I have a few spare computers at home, and I like the idea of them doing something useful. Problem is, they might be too elderly to make a contribution, so I decided to check here first.

The first rig is a Pentium 60. I know that an 80586-class machine is powerful enough to do some factoring work, but there's a catch. I tested it, and it has the infamous bug in the floating-point divide instruction. (The FDIV bug). Now I don't want to turn in incorrect results. Is there a way to force the program to use an integer-based routine, or otherwise avoid the floating-point divide?

Next up is an 80486DX, running at 20 MHz. This one might have a problem with memory, it only has 5 MB at it's disposal. Enough power?

The final one, a 25 MHz 80486SX. No math coproscessor. This one runs on 12 MB I think, but I'm not sure how lack of an FPU will affect things.

I suppose my 8 MHz 80286 is beyond hope.

Anyhow, is it woth keeping these old rigs in service?
Doorbasher is offline  
Old 2004-08-23, 00:55   #2
clowns789
 
clowns789's Avatar
 
Jun 2003
The Computer

23×72 Posts
Default

Perhaps you could go to Lone Mersenne Hunters and click on Operation Billion Digits. You won't get Primenet credit, but it's great for old computers.
clowns789 is offline  
Old 2004-08-23, 08:53   #3
xilman
Bamboozled!
 
xilman's Avatar
 
"π’‰Ίπ’ŒŒπ’‡·π’†·π’€­"
May 2003
Down not across

2×72×109 Posts
Default

Quote:
Originally Posted by Doorbasher
Hey evryone.

I have a few spare computers at home, and I like the idea of them doing something useful. Problem is, they might be too elderly to make a contribution, so I decided to check here first.

The first rig is a Pentium 60. I know that an 80586-class machine is powerful enough to do some factoring work, but there's a catch. I tested it, and it has the infamous bug in the floating-point divide instruction. (The FDIV bug). Now I don't want to turn in incorrect results. Is there a way to force the program to use an integer-based routine, or otherwise avoid the floating-point divide?

Next up is an 80486DX, running at 20 MHz. This one might have a problem with memory, it only has 5 MB at it's disposal. Enough power?

The final one, a 25 MHz 80486SX. No math coproscessor. This one runs on 12 MB I think, but I'm not sure how lack of an FPU will affect things.

I suppose my 8 MHz 80286 is beyond hope.

Anyhow, is it woth keeping these old rigs in service?
I keep a bunch of old machines in service though, not at the moment, anything quite as slow as a 486. Until about a year ago I had some DECStations running which were about as powerful as a 486DX2-66.

Anyway: all those machines can do something useful but you have to decide first whether you want to keep them powered up. Where I live has a miserable climate and so running fan heaters is fairly good idea most of the year. Getting computation from my heaters is a bonus.

What you may find difficult is using George's code to work on old systems because, as you point out, some of them don't have either enough memory and/or a working fpu. If you are prepared to download other software, UBASIC for instance, you can try factoring relatively small Mersenne numbers with ECM.


Paul
xilman is online now  
Old 2004-08-23, 11:51   #4
smh
 
smh's Avatar
 
"Sander"
Oct 2002
52.345322,5.52471

29·41 Posts
Default

Doesn't GMP-ECM and the ecmnet client work on a 486?

I'm not sure if they're worth the electricity though.
smh is offline  
Old 2004-08-23, 14:41   #5
Doorbasher
 
Aug 2004

22·3 Posts
Default

Well, I'm a 17-year-old nerd that lives in his parents' basement. I've accumulated some 16 computers over the years, and my parents give me pretty much free reign over how much electricity I use.

I'm thinking that the 486DX just dosent have the memory, and the other one dosent have the FPU. The Pentium 60 is still possible though, but it has that bug. Does anyone know either of a workaround for it, or if Prime95 (or perhaps the factoring program they use in Operation Billion Digits) uses floating point? Even if it dosent I'm going to ty and get my dual Pentium 120s working on that project, once I can get it to see it's hard drives.
Doorbasher is offline  
Old 2004-08-23, 22:18   #6
Pegaso
 

A5A16 Posts
Red face Old is the wind and still blows

Nonsense. I have five 486 DX4/100, with 12 Mb running all the stuff of Msoft and they doing excellent job factoring. They ARE SLOW but they WORK Fine.
AAh, also have a 386 Rapidfire or something like that, and also do a decent job.
Regards
Carlos
 
Closed Thread

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Which job for very slow machines? heliosh PrimeNet 10 2018-01-15 12:32
Slow Down? R.D. Silverman GMP-ECM 55 2011-10-16 17:28
GMP ECM slow on my laptop? R.D. Silverman GMP-ECM 9 2011-02-17 14:57
How hot is too hot? Slow is too slow? petrw1 Hardware 13 2008-11-10 23:25
Factoring so slow?? xtreme2k Software 7 2003-03-13 04:12

All times are UTC. The time now is 21:03.

Fri May 14 21:03:22 UTC 2021 up 36 days, 15:44, 0 users, load averages: 1.94, 2.26, 2.17

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.

This forum has received and complied with 0 (zero) government requests for information.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation.
A copy of the license is included in the FAQ.