Phenom 955 v. core i7

[rockdiablo]

Hey,
I need a new machine, i'm looking at the phenom 955 vs. the core i7 940.

This will be a workhorse which will have 4 java threads running at 100% whenever its being used. It will probably be running fc10 and i might not install X.

I have an i7 940 machine right now running that i've tried running 8 threads (trying to take advantage of the hyperthreading) on and it doesn't handle them well. I've left HT enabled, because I think that it works well for a desktop machine - switching btwn many applications, etc. 4 threads at 100% seems to run well, but i think that i'm seeing some overhead that i dont know if i'd see with an old style chip. anyways. here's the question:

Can anybody compare the phenom quad cores to the core i7s for something like this?

thanks.

 

[r_manic]

If you're really looking for multi-threading, I'd get an i7 920. What do you mean the 940 "doesn't handle them well"? Very slow? Unreliable? What exactly?

 

[rockdiablo]

with 8 logical threads running a 8 instances of the same program that should use up 100% cpu each, the system monitor shows about 20% usage on each log. cpu. Must be something about swithcing memory for the hyperthreaded logical cpus. When I run 4 instances of the same program, i get 100% usage for a while on each core then 0% then 100% again. I know that the same applications run on 2 athalon mps will get 100% consistatly with no drops down to 0%.

 

[rockdiablo]

similar (worse) results with the same thing in SMP with 8 threads, but its more straightforward above.