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Old 2005-09-25, 21:00   #1
Sep 2005

2 Posts
Default Program Optimization for dual processor machines


I've recently started running Prime95 on my dual processor machine. Now I'm curious as to the steps I can take to optimize it while it runs. I've already noticed that I need to start two instances of the program (setting each affinity to a unique CPU), and set the to run on start up. However, even when I do this, only one instance starts up at boot-up, forcing me to manually spawn the other instance.

I've set the ram used by each instance to around 500MB. My questions are as follows:

a) Is there any way to have both instances start on boot-up (as opposed to only having one start?)

b) Are there any other optimizations I might make?

Major specs are:

Dual Xeon Processors (3.2GHz, 800MHz FSB) with 2GB RAM. (More detailed specs available on request).

Also somewhat off-topic, searching the Intel site I found Intel Math Libraries that claim to further optimize the running of programs on Intel Machines.


Does Prime95 already make use of these types of libraries?



Last fiddled with by Altrus on 2005-09-25 at 21:06
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Old 2005-09-25, 21:43   #2
JHagerson's Avatar
May 2005
Naperville, IL, USA

22·72 Posts

I don't have any problems getting two instances of Prime95 to start at bootup. You might need to go to the Options menu and turn Start at Bootup off, then go back to the same menu and turn it on. To see if Prime95 is set to start at bootup, right-click on My Computer and choose Manage. In the Computer Management window, under the heading Name, double-click Services and Applications, then double-click Services. Scroll down and verify that you have an entry for the Prime95 service and that it is set to start automatically. I have found that when I first install Prime95, I need to reboot the computer before the Start at Bootup setting "takes."

As to libraries (Intel or otherwise), the guts of Prime95 are all hand-coded assembler language. George don't use no libraries!
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Old 2005-09-25, 22:00   #3
moo's Avatar
Jul 2004

809 Posts

Are you running windows...
if yes
then disable start at bootup in prime95 and write a quick bat file and place in startup folder....
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Old 2005-09-25, 23:29   #4
P90 years forever!
Prime95's Avatar
Aug 2002
Yeehaw, FL

11101110101102 Posts

Did you use the -A1 command line argument to start the second instance? I did that and have not had any problem with both starting at bootup.
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Old 2005-09-26, 15:19   #5
Sep 2005

2 Posts


Thanks for the replies - simply enough, just re-clicking the "start on boot up" option was enough :-)

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