Difficulty Running Prime with DSL

Rosenfeld · 2003-12-05, 19:18

I have been participating in GIMPS for six years and have not heard any mention of this problem. I recently installed SBC-Yahoo DSL service. Immediately, the Prime iteration times increased by a factor of 2-4 on my 1.7G-P4. I currently am testing an exponent of 20.6M and iteration times jumped from .110 to .300-.450 or higher. Worse yet, after about 30 minutes, the iteration times abruptly increase to 7.550 sec/iter! Stopping, closing and restarting Prime does not change the times. Other processes are also noticeably slowed. The 7.5 sec/iter times remain until I restart the computer.

Is there a solution or are DSL and Prime incompatible?

Reboot It · 2003-12-05, 19:25

You would probably benefit from doing a little detective work to see if anything else is "stealing" processor cycles or using them needlessly. This is really easy if you are using Windows 2000 or XP: just run Windows Task Manager and look at what processes are using what percentage of the processor's power and do look closely at Prime95 itself to see how much it is using. You may need to do some averaging over several minutes, or perhaps even longer. Do start this process after rebooting and try to watch it through the 30 minute "slowdown" period.

A word of warning: do not stop any process or try to alter its priority unless you really know exactly what it does - you can get a bit stuck if you do!

Post some feedback here with your initial findings and anything that looks out of place, together with a couple more details: Windows version, total RAM, whether you have antivirus or firewall software, anything that seems relevant. There are plenty of people here who will try to help you if they can.

PageFault · 2003-12-05, 19:25

It looks like you are using a USB (garbage) dsl modem. If so, get an ethernet modem. Similar problems have been noted when I use spazzle - crap USB interface.

Rosenfeld · 2003-12-05, 19:41

Details:
I am running under Windows XP. When the problem first occurred, I increased the computer memory from 256M to 512M. This is the maximum that the computer, a Dell, can have. I have Norton Anti-Virus.

When the system locks up, Task Manager reports that there are 37 processes with SVCHOST.exe and System are using 95% of he time. Prime occasionally gets 6%.

PageFault · 2003-12-05, 19:57

Can you answer, USB modem or not? There is a bad driver or you have been hijacked. 37 copies of svchost is bad news - two or three is normal and they shouldn't be using any cpu - total 6 seconds on my main box, for 1000+ hours of uptime.

markhl · 2003-12-05, 21:01

I also have SBC-Yahoo DSL with Prime95 and it works fine for me, do not have this problem. I agree that you have a lot of copies of svchost! PM or e-mail me if you want.

Rosenfeld · 2003-12-05, 22:51

I have an ethernet modem.

I want to clarify about the processes. I just checked and there are 39 processes running, 5 of which are SVCHOST.EXE. One of the five is using over 50% of the processing time, with almost all of the rest used by the process "System".

Thanks for the quick responses.

flava · 2003-12-05, 23:11

Are you using a PPP program while connected? Some of them are full of bugs and spyware (like kazaa).

PageFault · 2003-12-05, 23:19

Looks like a hijack - svchost and system don't actually do anything post boot - something is hiding behind the scenes there.

edit:

If you know how, set up resource monitoring and select network usage, choosing a plot for display. We had some attacks at work and that allowed us to identify the problem machines - they were hijacked to serve illegal movie rips.

Uncwilly · 2003-12-05, 23:22

Sounds like you need a firewall and maybe a dynamic IP.

call_apple · 2003-12-05, 23:31

I would suspect spyware on your box.

Go to download.com and download and run Ad-aware 6.0

2003-12-05, 19:18	#1
Rosenfeld Aug 2002 9₁₀ Posts	Difficulty Running Prime with DSL I have been participating in GIMPS for six years and have not heard any mention of this problem. I recently installed SBC-Yahoo DSL service. Immediately, the Prime iteration times increased by a factor of 2-4 on my 1.7G-P4. I currently am testing an exponent of 20.6M and iteration times jumped from .110 to .300-.450 or higher. Worse yet, after about 30 minutes, the iteration times abruptly increase to 7.550 sec/iter! Stopping, closing and restarting Prime does not change the times. Other processes are also noticeably slowed. The 7.5 sec/iter times remain until I restart the computer. Is there a solution or are DSL and Prime incompatible?

2003-12-05, 19:41	#4
Rosenfeld Aug 2002 11₈ Posts	More Details Details: I am running under Windows XP. When the problem first occurred, I increased the computer memory from 256M to 512M. This is the maximum that the computer, a Dell, can have. I have Norton Anti-Virus. When the system locks up, Task Manager reports that there are 37 processes with SVCHOST.exe and System are using 95% of he time. Prime occasionally gets 6%.

2003-12-05, 23:19	#9
PageFault Aug 2002 Dawn of the Dead 5·47 Posts	Looks like a hijack - svchost and system don't actually do anything post boot - something is hiding behind the scenes there. edit: If you know how, set up resource monitoring and select network usage, choosing a plot for display. We had some attacks at work and that allowed us to identify the problem machines - they were hijacked to serve illegal movie rips. Last fiddled with by PageFault on 2003-12-05 at 23:22

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2003-12-05, 19:25	#2
Reboot It Aug 2002 London, UK 5·19 Posts	You would probably benefit from doing a little detective work to see if anything else is "stealing" processor cycles or using them needlessly. This is really easy if you are using Windows 2000 or XP: just run Windows Task Manager and look at what processes are using what percentage of the processor's power and do look closely at Prime95 itself to see how much it is using. You may need to do some averaging over several minutes, or perhaps even longer. Do start this process after rebooting and try to watch it through the 30 minute "slowdown" period. A word of warning: do not stop any process or try to alter its priority unless you really know exactly what it does - you can get a bit stuck if you do! Post some feedback here with your initial findings and anything that looks out of place, together with a couple more details: Windows version, total RAM, whether you have antivirus or firewall software, anything that seems relevant. There are plenty of people here who will try to help you if they can.

2003-12-05, 19:25	#3
PageFault Aug 2002 Dawn of the Dead 11101011₂ Posts	It looks like you are using a USB (garbage) dsl modem. If so, get an ethernet modem. Similar problems have been noted when I use spazzle - crap USB interface.

2003-12-05, 19:57	#5
PageFault Aug 2002 Dawn of the Dead EB₁₆ Posts	Can you answer, USB modem or not? There is a bad driver or you have been hijacked. 37 copies of svchost is bad news - two or three is normal and they shouldn't be using any cpu - total 6 seconds on my main box, for 1000+ hours of uptime.

2003-12-05, 21:01	#6
markhl Apr 2003 California 1011100₂ Posts	I also have SBC-Yahoo DSL with Prime95 and it works fine for me, do not have this problem. I agree that you have a lot of copies of svchost! PM or e-mail me if you want.

2003-12-05, 22:51	#7
Rosenfeld Aug 2002 3² Posts	I have an ethernet modem. I want to clarify about the processes. I just checked and there are 39 processes running, 5 of which are SVCHOST.EXE. One of the five is using over 50% of the processing time, with almost all of the rest used by the process "System". Thanks for the quick responses.

2003-12-05, 23:11	#8
flava Feb 2003 118₁₀ Posts	Are you using a PPP program while connected? Some of them are full of bugs and spyware (like kazaa).

2003-12-05, 23:22	#10
Uncwilly 6809 > 6502 """"""""""""""""""" Aug 2003 101×103 Posts 3×7×17×31 Posts	Sounds like you need a firewall and maybe a dynamic IP.

2003-12-05, 23:31	#11
call_apple Nov 2002 Ashburn, Va. 21₁₀ Posts	I would suspect spyware on your box. Go to download.com and download and run Ad-aware 6.0