Re: [tlug] Have an un-used Opteron?

[Josh Glover <jmglov@example.com>]

2009/3/6 Nick Bikkal <nickbikkal@example.com>:

> I'm thinking of making one myself, if you could tell me how the
> hyperthreading works

Not sure if I understand what you mean here, but hyperthreading is
basically a software (the software embedded in the CPU itself) trick
to make one core look like two to the OS:

http://en.wikipedia.org/wiki/Hyper-threading

In my opinion, here is how multi-core, hyper-threading, and vanilla
rank, in descending order of desirability:

1. Multi-core with hyper-threading enabled
2. Multi-core
3. Single core with hyper-threading enabled
4. Vanilla (singe core, hyper-threading disabled)

In short, hyper-threading can give you modest performance gains for
some classes of applications, and almost never results in performance
losses. Turn it on, just know that it is no magic bullet.

Jeff Atwood has had a lot to say about this over the years over at
Coding Horror:

http://www.codinghorror.com/blog/archives/000169.html
http://www.codinghorror.com/blog/archives/000285.html
http://www.codinghorror.com/blog/archives/000353.html
http://www.codinghorror.com/blog/archives/000655.html
http://www.codinghorror.com/blog/archives/000688.html
http://www.codinghorror.com/blog/archives/000867.html
http://www.codinghorror.com/blog/archives/000942.html

-- 
Cheers,
Josh