I am about to replace an aging PIII with a new computer once Windows 7 is out.

My question is about a good CPU for crunching. My friend has a Core 2 Quad which is terrific. He says the news in the forums about the I series, 5's and 7's, not so hot.

I have no problem staying back with a Core 2 Quad, but will the BOINC software soon benefit from work to accomodate the I series CPU's ?

Thanks for any advice.

---

http://sciencesprings.wordpress.com
http://facebook.com/sciencesprings

I have no problem staying back with a Core 2 Quad, but will the BOINC software soon benefit from work to accomodate the I series CPU's ?

Anything special you're looking for? BOINC will give you the chance to run a science application on whichever amount of CPU cores (real or hyperthreading) you want to give to it.

Other than that, there are no optimizations specifically geared towards any CPU brand or options it has. Not in BOINC at least, if a project wants to use that (talking about SSE, SSE2, SSE3 etc. here) they will have to add that to their science applications.

BOINC doesn't crunch, it's a manager only.

---

Hey Jord-

I did a search in I7 of this forum, and found nothing of any note. I did the same search in a WCG forum and found a huge amount of activity especially in respect to the hyperthreading in the I7 and the need to turn it off.

So, I am just looking to optimize whatever I buy. I do know that BOINC does not crunch, and I also know that WCG does their own compiling. I am just trying to find out if there is a reason to buy the core 2 quad and stay away from the I7.

>>RSM

---

http://sciencesprings.wordpress.com
http://facebook.com/sciencesprings

Hey Sek-

Thanks for your good words. It will be an I7.

>>RSM

---

http://sciencesprings.wordpress.com
http://facebook.com/sciencesprings

In case other people read this forum and try to decide between an i7 and core2quad or something of the sorts

Virtually all bad hyper threading performance is with the P4 line.

My Boinc benches my corei7 2.66hz at 2650 Whetstone(2.65 billions flops/sec) and 6800 Dhrystone (6.8billion ints/sec)

This puts it at 2 flops/cycle per core or 1 flop/cycle per logical cpu and a bunch more ints/cycle.

hyper threading is almost perfect on the i7 except for SSE. *Some* SSE execution pieces are not duplicated so only one logical cpu per core may issue certain instructions at a time. According to the specs, the i7 can issue 8 single pres floats via SSE, so if you core could take advantage of the SSE, it would still be a large performance increase even if only 1 logical cpu per core could use it. Even then, you can issue different SSE instructions per logical cpu, just not the same of certain ones.

Back with the P4, it was HIGHLY recommended to turn off hyperthreading for databases because it almost always caused a slow down. The i7 2.66 quad core performed 100%-450% faster than a quadcore Xeon of the core duo line on a 1.5TB database doing cubed olap stuff. Ohh, and the i7 uses as much power as the core2quad, so you use the same amount of power but get 2xs-5.5xs the performance.

An on the side note. A recent test showed Win7 uses ~17% less power on an i7 than Vista/XP because of the new thread scheduler. This won't really help if you have your computer pegged, but when you have 1+ more cores idle, the scheduler will try to keep threads off of that core and the i7 can COMPLETELY turn off power on that core. Since these turn offs happen on sub milisecond levels, the i7 can actually do this quite often.

I hope this helps

I did my deal, I7-920, and everything looks good in BOINC Manager, 8 WU's running.

Thanks for the great advice.

>>RSM

---

http://sciencesprings.wordpress.com
http://facebook.com/sciencesprings

On old P4 with HT on gave an increase in RAC than with it turned off. Individual wu's may have taken longer but since you were doing 2 at the same time there was on overall increase in crunching capability in the BOINC world.

I do recall the issue with DB accessing, but in BOINC it was the cpu to have for a while.