Multi-processor machines

[jthomet]

Okay, I've been an avid Linux fan for some time; but now for a really dumb question: How's the support for multi-processor machines in Linux (preferrably in the RedHat flavor)?

[MBMarduk]

I'm not too up-to-date on this.
But some people swear by it, while a great many others are very sceptical whether it's useful for home use.

I've heard some thing about the Linux kernel not multi-threading correctly; but I think that was about kernel 2.0.x

I've also heard that in some instances, with games, office-apps and the like you'll actually get a performance HIT 'cuz of the time spent forking processes for the sake of using more processors. (people, correct me if I'm wrong?!)

So I think it's only useful if you're gonna install a heavy-duty server.

Do a Google search on the subject and you'll get much more and BETTER info on this.

-Mike

[jthomet]

Thanks for the heads-up. I was just curious about the present support for it. I'll go do some digging and will likely post my findings here for anyone else that may be curious.

[Marcel2008]

Running 2 proccesors is like having a wagon with 2 horses, you will not go twice as fast, but one can take over the running from the other.

It's nice if you are using multiple processes on the same machine.

[hungarian]

SMP support is very good under Linux kernel 2.2.19 from the 2.4 series pick the latest 2.4.3.
All in all if your program is not written for SMP then it will not run any faster.
But if it is correctly supporting SMP then there can be a significant gain in speed.

AMD will bring out a new chipset this year that will support SMP on their Athlon chips(I don't know if this is the case with Durons.)

[hndpaul]

I agree with all that's been said here. If you have kernel 2.4.x and have SMP configured into your kernel (you may have to recompile), then that's only part of the battle. Next you have to really run applications that will *use* the dual capability of your system. I think GIMP can be used this way, but am not sure. Povray can be used this way, and most compute intensive science applications etc.

The speed gains can be anything from amazing to tiny. It depends on just how well the SMP system is coded and how well the application has been written. Generally I think it would be worth a go (even for educational purposes).

Wait for the AMD SMP chipset due soon and use two 1GHz Athlons....nice.. :D

Paul, UK