i am wondering if gentoo can utilize the 64 bit feature of dual quad
core xeons (E5405 harpertown). i am also wondering if it is possible
to run all eight cores simutaneously on folding@home with gentoo. i
apologize if i am asking stupid questions. hope i am not out in left
field with this post. thank you in advance for your consideration in
this matter.

as long as you use a 64 bit linux, you can fully utilize all 64 bit functionality of any processor. The number of processors has no bearing on this.

I don't know enough about folding @ home, but there's nothing stopping an application that will run 8 threads from fully utilizing all 8 cores. The code would have to be well written for this to be the case, of course, but it's certainly possible.

BrianK:
thank you for your swift reply! i will get busy installing gentoo amd64 tonight. i guess i will just have to see what folding@home will do. thanks again!

Sorry if I am asking a dumb question but Jimerickso how is the genral performance of these XENONs in comparision to say a core 2 quad in windows and linux? i mean if i want to buy I pc to run games, what would be preferrable a XENON or a usual core2 duo/c2quad ? [if budget isint the issue]?

XEON is not a meaningful model name. It tells you almost nothing about the CPU.

I'm not sure how to interpret the meaningful Intel model info. I expect the "E5405 harpertown" mentioned in the initial post does mean something (at least to someone who understands more of Intel's naming system).

If you're trying to compare some possible purchase with "XEON" in its name to some alternate purchase without "XEON", you're looking at the wrong part of the model name. The exact same CPU might be sold both with and without the name XEON and many totally unrelated CPU models are all sold with the name XEON. It really tells you nothing.

If you were running a single threaded (& non-forking) process, then extra cores do not help much, assuming you are not running anything else except the OS.
The prog has to be written to take advantage of the extra cores to see dramatic improvements.

ok. well if you dont have optimised applications then core 2 quad /core2 duo wont be of any use either.What I meant to ask is, in terms of performance (for single threaded or muliti threaded applications) Intel XEON E5405 harpertown will be comparable to which of the 'consumer' market, and ultimately whats the difference between E5405 and Q9000 or QX9000 because from specs I think they are similar?

If you are buying a pc to run games, maybe you shouldn't even be considering quad core (and maybe not Linux either).

I don't run games and much of what I've read about games and seen from my sons running games, may be obsolete information. But to the extent I understand it, very few games are multi-threaded, so they can't take direct advantage of multiple cores.

Many single threaded games depend (for decent performance) on ultra low CPU latency. Even if the game is the only thing you're running on a single core system, various network traffic and other system overhead can interrupt and prevent the game from getting ultra low latency use of a CPU.

But as soon as you add a second core, all those latency problems go away. Adding more cores beyond the second makes no further difference (unless the game software is multi-threaded).

Even the second core probably won't affect performance measures such as average frame rate. But it may significantly affect the feel of playing the game.

Since you didn't ask about Linux (vs. Windows) game support, I won't say more about that beyond suggesting that you try to make an informed decision.

Is Q9000 a model (with specific specs)? Or just a family of a few models, each of which have different specs?

Dell sells a lot of XEON CPUs in seriously overpriced systems with motherboards that support two CPU packages per motherboard. I don't know which CPU models can be used in such motherboards. Maybe that is a meaningful difference between models where the basic specs are the same. But if so, I assume it wouldn't matter to you, because you shouldn't be considering a system with two CPU packages.

I don't know what else you can reasonably consider in comparing CPUs other than the major specs, such as clock rate, L2 cache size etc. Maybe some other expert here will give us a useful answer to that, but I doubt it. Ultimately, if you can't understand why a more expensive model with similar specs is better, that is probably because it isn't.

johnsfine thanks for the reply.Anything above dual core isint completely useless, say for example the extra shared l2 cache in cure 2 quads can help the 2 cores [but that would be an over kill to say the least,and I agree if i will buy a new system, i would certainly be just 2 processors].
What I basically want to ask is whats the difference beteween those quad core xenons and their consumer counterpart?

folding @ home has a SMP package for symetric multi processing. folding @ home can take advantage of your 8 core processor, just dont forget to have all them purdy cores folding for the LINUX QUESTIONS FOLDING TEAM!!!! our team number is 12776 =)

Used to be the config option for maximum number of CPUs could trip you up - these days a low number like "8" shouldn't be a problem. Changing it on gentoo is a no-brainer anyway.

I wasn't aware folding@home now has a SMP version, but years ago I used to run two separate instances of folding@home on a dual core machine, each instance ran independently working on different units.