Hyperthreading

[Prodigious]

Pardon me if this has already been discussed, but what is the status of Prime95 supporting P4 Hyperthreading technology?

Thanks.

[adpowers]

Someone correct me if I am wrong, but I don't think hyperthreading would help Prime95 at all. First of all, it is implemented by the processor, so you don't need support from the software. Second of all, it is used for running two or more threads concurrently (often from different programs). However, in order to run multiple threads, they have to use different parts of the CPU. For example, one could be doing floating point calculations while the other is using SSE2. Since Prime95 would max whatever part of the processor it is using, you can't have two instances of Prime95 hyperthreading (unless, possibly, one is running LL tests and the other is double checking). However, if Prime95 is running on a hyperthreading computer and you turn on, for example, a program compile, then you should get better performance than if you didn't have a hyperthreading computer. In short, I am trying to say that if Prime95 is left alone on a computer, it shouldn't make any difference, but if you do something on your computer, then you may see an increase versus a non-hyperthreaded machine.

Andrew

[ET_]

I am looking for some documentation about Assembly code optimization for new processors.
My (old) source was Quantasm "Pentium optimization tools".

Can anybody point me to a more complete book or documentation, dealing with SSE, SSe2, pipeline and cache optimization?

Thank you :)

Luigi

[Xyzzy]

http://webster.cs.ucr.edu/Page_asm/ArtOfAsm.html

No SSE/SSE2 but still a very fun website about assembly...

[ET_]

Thanks ;)

Meanwhile I found the Intel Pentium 4 programming manuals.

Luigi