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Old 2010-03-27, 17:26   #1
esqrkim
 
Mar 2010
California, USA

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Default Does overclocking help?

I have a Quad 9550 (2.83 MHz) with 4GB of RAM (1066 MHz) in Asus P5Q Pro Turbo MB. I recently overclocked the CPU to 3.20 MHz and left everything else to auto in the BIOS, but did not see noticeable difference in LL iteration times. What's happening? Do I need to overclock more to see significant difference or should something else be overclocked to see the benefits of the CPU being overclocked?

Thans for your help.
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Old 2010-03-27, 21:50   #2
joblack
 
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Quote:
Originally Posted by esqrkim View Post
I have a Quad 9550 (2.83 MHz) with 4GB of RAM (1066 MHz) in Asus P5Q Pro Turbo MB. I recently overclocked the CPU to 3.20 MHz and left everything else to auto in the BIOS, but did not see noticeable difference in LL iteration times. What's happening? Do I need to overclock more to see significant difference or should something else be overclocked to see the benefits of the CPU being overclocked?

Thans for your help.
Normally you should see a difference. The Q-series will automatically downclock if they get too hot. Check out the temperature with a windows tool (or use sensors for Linux) to get the working temperature (downclocking occures around 85 C). Additionally you can check the /var/log/syslog for 'downclock' messages ...

Last fiddled with by joblack on 2010-03-27 at 21:51
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Old 2010-04-03, 06:50   #3
esqrkim
 
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I got the Q9550 running at 3.57 GHz. After 26% increase in speed, I can clearly see the difference in processing LL tests. The temp seems to hover between 53C and 56C depending on the time of day. The HDT-S1283 is really making a difference on controlling the temp.
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Old 2010-04-03, 15:18   #4
lycorn
 
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Just watch for errors that may occur (SUMOUT, or similar stuff...). In order for the OC to be effective, it shall not induce errors in the tests. If you have a 20 or 30% decrease in the completion time due to OC its fine, but if the test turns out to be incorrect, all the work goes to waste, and it would have been better to complete the test slower, but with a correct result.
In general, when one starts overclocking a given machine, it´s good practice to run a couple of DCs first, and see if they match the previously reported results, so one gets confident that the OCed machine is running smoothly before starting first time LLs.

Last fiddled with by lycorn on 2010-04-03 at 15:20 Reason: typo
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Old 2010-04-03, 15:27   #5
joblack
 
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Quote:
Originally Posted by lycorn View Post
Just watch for errors that may occur (SUMOUT, or similar stuff...). In order for the OC to be effective, it shall not induce errors in the tests. If you have a 20 or 30% decrease in the completion time due to OC its fine, but if the test turns out to be incorrect, all the work goes to waste, and it would have been better to complete the test slower, but with a correct result.
In general, when one starts overclocking a given machine, it´s good practice to run a couple of DCs first, and see if they match the previously reported results, so one gets confident that the OCed machine is running smoothly before starting first time LLs.
Just watching the error rate isn't enough. The cpu could downclock before getting error messages. If you run Linux you can check out /var/log/syslog for downclock messaging.
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Old 2010-04-06, 18:11   #6
rx7350
 
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You mentioned you 'left everything else to auto' . Did the memory overclock as well? Memory is the bottleneck for a Q9950, and increasing the frequency of the memory will have a dramatic effect on iteration times, usually more so than increasing cpu speed.
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Old 2010-04-17, 04:15   #7
esqrkim
 
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No, I did not overclock the RAM. I did increase the RAM voltage to 2V to match the hardware spec.

The Asus software is not as good as going directly into the BIOS. By setting the FSB to 424, I was able to get the CPU speed to be 3.6 GHz. Now, all four of my cores show 0.07 seconds for iteration time. I also noticed that simply having the ethernet cable connected adds 0.001 seconds to the iteration time.

I could push the CPU some more, but I don't want to be too greedy. The speed increase that I've already gained has made my CPU worth several times more than what I paid. So, I'm satisfied. In addition, I'd like to keep the CPU temperature below 60C on a hot day. Right now, the temp is going up to 58C on a hot day.

Last fiddled with by esqrkim on 2010-04-17 at 04:17
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Old 2010-06-26, 08:15   #8
musicworld1
 
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How can i do this better.
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