Sieve Benchmark Thread

[mdettweiler]

Originally Posted by Oddball

That's because Turbo Core was on. With all 6 cores loaded and no background tasks, I'm getting 85M p/sec, or 14.2M p/sec/core.

Doing things like browsing the web and using Microsoft Word drops the rate to about 82M p/sec, but it's still much faster than my old Pentium 4.

Pardon my ignorance but, what's Turbo Core? Is it some kind of temporary automatic-overclock thing?

[Oddball]

Originally Posted by mdettweiler

Pardon my ignorance but, what's Turbo Core? Is it some kind of temporary automatic-overclock thing?

It's like Intel's turbo boost:

http://www.intel.com/technology/turboboost/

If 3 or more cores are idle and the CPU is cool enough, it automatically increases frequency from 2.8 GHz to 3.3 GHz and shuts down the other cores. But if most of the cores are active, the CPU remains at 2.8 GHz.

[mdettweiler]

Originally Posted by Oddball

It's like Intel's turbo boost:

http://www.intel.com/technology/turboboost/

If 3 or more cores are idle and the CPU is cool enough, it automatically increases frequency from 2.8 GHz to 3.3 GHz and shuts down the other cores. But if most of the cores are active, the CPU remains at 2.8 GHz.

Ah, I see. I suppose that would complicate benchmarks a bit--it's a somewhat common practice to leave some or all of the other cores in a machine idle when running a one-core benchmark, but it would seem in this case that one would want to keep at least 3 busy in order to ensure an unskewed result.

BTW, have you considered overclocking your machine? If you have something better than the stock heatsink/fan cooling your CPU, then it's a good way to get a tidy performance boost even with all cores running. I personally have my Core 2 Quad Q6600 overclocked to 2.8 Ghz (from 2.4) and it runs stably (and noticeably faster) at that frequency without having to increase the CPU voltage at all.

[Oddball]

Originally Posted by mdettweiler

BTW, have you considered overclocking your machine?

Not now. Room temperatures sometimes get up to the low 80's (27-28 degrees Celsius) during the hottest time of the day, so it'll be hard to keep the CPU cool enough if it's overclocked by a noticeable amount.

I might consider overclocking in October or November, when temperatures drop to the mid-low 60's. It would be pretty awesome to get a round number of 100M p/sec.

[Oddball]

Originally Posted by Oddball

With all 6 cores loaded and no background tasks, I'm getting 85M p/sec, or 14.2M p/sec/core.

BTW, have you considered overclocking your machine? If you have something better than the stock heatsink/fan cooling your CPU, then it's a good way to get a tidy performance boost even with all cores running.

Well, it looks like I didn't need an overclock to get that increase in speed. Switching from the 64 bit version to the SSE2 version boosts performance to an astonishing 134M p/sec

At this rate, a 10T range would take less than a day to complete.

One core of an AMD Phenom II @ 2.8 GHz: 16.6M p/sec

With one core running and all other cores idle, I get a rate of 26.1M p/sec using the SSE2 version. The 64 bit version produces the same benchmark as yours.

[MooMoo2]

Originally Posted by Oddball

Switching from the 64 bit version to the SSE2 version boosts performance to an astonishing 134M p/sec

Sieve speed seems to vary for no apparent reason. While sieving in the 500T range, I was getting 133M p/sec if all cores were on with the SSE2 version. But now, in the 700T range, performance goes up to 138M p/sec, but it drops again to 132M p/sec at 7000T.

[Lennart]

I am testing tpsieve-cuda on a gts250 card.

test file 480k-485k
test range 735T-740T
57Mp/sec ETA 5T ~ 24hr

Lennart

[MooMoo2]

What types of speeds would we expect to see on a high-end GPU? According to this post: http://www.mersenneforum.org/showpos...&postcount=298
high end GPU's are about 60 times faster than low end ones.

[mdettweiler]

Originally Posted by MooMoo2

What types of speeds would we expect to see on a high-end GPU? According to this post: http://www.mersenneforum.org/showpos...&postcount=298
high end GPU's are about 60 times faster than low end ones.

On a GTX 460 (slight factory overclock IIRC):

n=480K-485K (August file)
p=1010T-1015T
279M p/sec.
ETA ~5 hours

This is with command line flags -m 38400, -Q 10e6, which seem to be optimal for this GPU on this sieve.

[Bottom Quark]

I'm getting 51M p/sec on a core i3 laptop @ 2.4GHz.

[cipher]

I am thinking about getting a radeon ATI 5770 or 5870 can some one run tpsieve for openCL and let me know the benchmark.

http://www.mersenneforum.org/showpos...48&postcount=2

Thanks.

Please run the benchmark for twin prime sieve Range 1
http://www.mersenneforum.org/showpos...66&postcount=1