PPD question

[Ichelo351]

Hey all,
i was wondering what the PPD difference between the smp client and 4 reg clients on a quad-core xeon running linux native

thanks!

[LandShark]

one word.................. Big!!!

[TommyHolly]

ChasR was just talking about this in my thread "How is everyone Red?"

He said 5,000 PPD!! Insane huh?

[LandShark]

ChasR was just talking about this in my thread "How is everyone Red?"

He said 5,000 PPD!! Insane huh?

5000ppd is from a near 4ghz quad core folding in ideal condition. most quad core crap out at a big over 3ghz (3.3-3.4 at best on air), in an ideal condition, it will produce about 4100-4400ppd.

[ChasR]

The numbers below apply to relatively high bandwidth Kentsfields.
In native linux on SMP you're very likely to get assigned to the "quad only" server and recieve p302x of p305x which are very cache intensive WUs. You can't run two of them at the same time (ppd goes in the tank) so ppd is limited to about 950 ppd/GHz. If you're not assigned to the "quad only" you run two instances and recieve two of the less cache intensive WUs (p2604, p2605, p2651, or p2653) you can get up to 1425 ppd/GHz. If you get two p2608s you'll see ppd/GHz tumble from 1425 to 920, less than the 1100 ppd/GHz you'd make on a single instance.
Compare that to the 70ppd/GHz/core you get on non bonus uni cpu WUs and you can see why almost everybody with a multicore cpu, particularly Intel, runs the SMP client. There are some bonus WUs and DGromacs out there that up the uni cpu client output substantially but you don't get them all the time.
Don't put the SMP client on a computer you don't have access to. It's beta and has an expiration date.