• Welcome to Overclockers Forums! Join us to reply in threads, receive reduced ads, and to customize your site experience!

quick question about P4 HT install

Overclockers is supported by our readers. When you click a link to make a purchase, we may earn a commission. Learn More.

U D13 N0W

Member
Joined
Mar 11, 2008
Location
Maryland
gotta quick question about installing on a P4 HT system. How do i go about setting up a client on the second core?
Im trying to run two seperate clients on this rig b/c it is not on too often so a SMP would be impractical.
 
While you can run two instances of a single core client on a HT enabled P4, Stanford asks that you do not. It slows down the science being done b/c it takes longer for two units to be completed. Besides, the ppd gain from doing so isn't that dramatic.

If you choose to do so, make two separate folders, fah1 and fah2, and select advanced setup options when setting your config. The last option should be machine id. Set the first instance in fah1 folder to 1 and the second instance in fah2 folder to 2.
 
The last time I tried doing this, the gain in PPD was not worth the slowdown as far as the science is concerned IMO. Just keep in mind, the P4 with HT is not a true dual core, instead it basically "virtualizes" a second core, so Winderz will still think it is a dual core CPU. Even though Task Manager will say you are only folding at 50%, you are actually folding at 100% (I like to think of this as a flaw in Microsofts programming). By running 2 clients simultaneously, you are essentially only using half the core to run one WU, while the other half is working the other. Depending on which P4 it is, it may be able to just barely make SMP deadlines, as I know ChasR has a few folding SMP. I do believe they are pretty dedicated to be able to make the SMP deadlines.
 
The last time I tried doing this, the gain in PPD was not worth the slowdown as far as the science is concerned IMO. Just keep in mind, the P4 with HT is not a true dual core, instead it basically "virtualizes" a second core, so Winderz will still think it is a dual core CPU. Even though Task Manager will say you are only folding at 50%, you are actually folding at 100% (I like to think of this as a flaw in Microsofts programming). By running 2 clients simultaneously, you are essentially only using half the core to run one WU, while the other half is working the other. Depending on which P4 it is, it may be able to just barely make SMP deadlines, as I know ChasR has a few folding SMP. I do believe they are pretty dedicated to be able to make the SMP deadlines.

Thanks for the info. I hadn't known all the details with HT. It sounds like a sales scam to make people think they are getting more for their money. Glad to know I'm actually getting 100% of the CPU on the folding. Also thanks to drshivas :beer:
 
It wasn't really a sales scam. There was something implemented in the architecture that makes it work somewhat like a dual core, but doesn't quite get close to the same speed increase. What you are likely to see is just a 30% increase, but at the time, you will still be slowing down the WU's which is bad for the science. Here is a Wiki article about HT that I have found. Hope this helps understand it a bit.
 
Glad I could be of some help. I just personally set up the SMP client on my 530J, but that is with a pretty good OC. I am hoping that it will make deadlines. It hasn't quite been long enough to get a PPD or TPF estimate from either FAHSpy or FAHMon, but as soon as I have those numbers, I will be sure to post them up.
 
Back