Running HT on my Prescott 3.0 ghz, I found that S39L and S40.04 was the fastest ones. ALL other bins were slower.
I also found S39L and S40.04 to be essentially equal and faster than any others I've tried on the Prescott with HT enabled. The differences between those two client versions are less than the noise level (differences between WUs) on that processor. I'm currently running S40.04 on my HT-enabled systems except for one on which I've installed U41.04 for testing.
Running S40.04 in HT mode, a wu took approx. 2.30 hours. After "disabling" HT mode S41.06 took 55 mins.
This means that in HT mode a wu took approx. 1.15 mins, now 55 mins.
Hope this clarifies my situation.
It is absolutely correct.
Both HT threads use the same FPU circuits, and both threads can load it near to 100% of their time, so both threads wait for the other. That means the processor is not able to run two threads paralell because it doesn't have more resources. It also means that the code use near to 100% of the resources.
The difference of the two time (1.15 vs 55) is very talkative.
It gives you the efficiency of HT system (in this case), so your system waste about 27% of the resources (time) to handle HT.
How does one go about disabling HT on a P4 (XP)? I would like to give it a try for comparison purposes.
-edit- nevermind, I've clued myself in
-edit- If one is only running Einstein, would it be best to leave on the HT as opposed to setting the affinity to one processor per project if running, for example, Einstein and Seti?
One thread on Einstein and the other one on Seti to reduce overhead and bottlenecks...
I can't see any significative difference between U41.04 and S41.07. Clearly the SSE3 instructions set are not so powerful on my Intel! My decision is to crunch with the U41.04 and I'll wait for a specific Intel version...
I'm sorry but at the moment I can't test S39L and S40.04 cause I will be away from home 'til monday. So next test are delayed!
Thanks again, Akos, ever for your clear explanations!! ;-)
It would be really good to clarify the speedups (or speeddowns) on Prescotts. Thanks.
I don't have the faciliites (or time) to do a full statistical comparison but, for my Pentium 4 (Prescott) 3.0 GHz machine I was taking about 150 minutes using S38, about 120 minutes with S40.12, while early tests with U41.04 are coming in at around 80 minutes.
The "official" version was taking 9 hours!
Needless to say I'm impressed.
Now if only Climate Prediction could be speeded up by a similar factor...
[One thread on Einstein and the other one on Seti to reduce overhead and bottlenecks...
How are you doing that? I badly want to do that on my Gallatin host, so I can raise the SETI resource fraction without losing the huge mixed-ap benefit. I run tx36 client.
How are you doing that? I badly want to do that on my Gallatin host, so I can raise the SETI resource fraction without losing the huge mixed-ap benefit. I run tx36 client.
I just figured this out today myself. Open Windows Task Manager (XP) and right click on the app exe. It will open a menu with "Set Affinity" at the bottom. Set one app to CPU 0 and the other to CPU 1.
RE: Running HT on my
)
I also found S39L and S40.04 to be essentially equal and faster than any others I've tried on the Prescott with HT enabled. The differences between those two client versions are less than the noise level (differences between WUs) on that processor. I'm currently running S40.04 on my HT-enabled systems except for one on which I've installed U41.04 for testing.
RE: Running S40.04 in HT
)
It is absolutely correct.
Both HT threads use the same FPU circuits, and both threads can load it near to 100% of their time, so both threads wait for the other. That means the processor is not able to run two threads paralell because it doesn't have more resources. It also means that the code use near to 100% of the resources.
The difference of the two time (1.15 vs 55) is very talkative.
It gives you the efficiency of HT system (in this case), so your system waste about 27% of the resources (time) to handle HT.
How does one go about
)
How does one go about disabling HT on a P4 (XP)? I would like to give it a try for comparison purposes.
-edit- nevermind, I've clued myself in
-edit- If one is only running Einstein, would it be best to leave on the HT as opposed to setting the affinity to one processor per project if running, for example, Einstein and Seti?
RE: It would be really good
)
Updates in Stats for my Intel P4 3.0Ghz Prescott (with SSE3) Hyper-Threaded:
S41.06 => 5273s (mean of 12 results) => 1.00
S41.07 => 4858s (mean of 5 results) => 0.921 (8% gain)
U41.04 => 4833s (mean of 5 results) => 0.916 (8% gain)
One thread on Einstein and the other one on Seti to reduce overhead and bottlenecks...
I can't see any significative difference between U41.04 and S41.07. Clearly the SSE3 instructions set are not so powerful on my Intel! My decision is to crunch with the U41.04 and I'll wait for a specific Intel version...
I'm sorry but at the moment I can't test S39L and S40.04 cause I will be away from home 'til monday. So next test are delayed!
Thanks again, Akos, ever for your clear explanations!! ;-)
RE: It would be really good
)
I don't have the faciliites (or time) to do a full statistical comparison but, for my Pentium 4 (Prescott) 3.0 GHz machine I was taking about 150 minutes using S38, about 120 minutes with S40.12, while early tests with U41.04 are coming in at around 80 minutes.
The "official" version was taking 9 hours!
Needless to say I'm impressed.
Now if only Climate Prediction could be speeded up by a similar factor...
RE: [One thread on Einstein
)
How are you doing that? I badly want to do that on my Gallatin host, so I can raise the SETI resource fraction without losing the huge mixed-ap benefit. I run tx36 client.
RE: How are you doing that?
)
I just figured this out today myself. Open Windows Task Manager (XP) and right click on the app exe. It will open a menu with "Set Affinity" at the bottom. Set one app to CPU 0 and the other to CPU 1.
This works but you have to do
)
This works but you have to do this for every new WU - not very practical in the long run.
MrS
Scanning for our furry friends since Jan 2002
Add the line to
)
Add the line to truxoft_prefs.xml file.
RE: This works but you have
)
Didn't know that. Thank you for the heads up.
Mike Hewson posted another way of changing HT through BIOS.