Hyper threading query

[CurlyWhirly]

I have Hyper Threading Technology disabled in the BIOS (it's off by default)

Would I gain performance by enabling it?

I'm wondering if it has anything to do with the fact that most of the time, even though I have a quad core processor, 2 of the cores seem to be doing most of the work whilst the other 2 cores are idle for most of the time

Could this be related to hyper threading being disabled or this normal for quad core processors?

I don't think much software has been written to take advantage of hyper threading thus far?

 

[decto]

I don't think the quad cores have hyperthreading, the new I7 might have though.

It's normal for some cores to have most of the work still as most applications use 1 or 2 threads so can't utilised many cores. 1 thread is captive to a core so the load cannot be spread.

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[CurlyWhirly]

I don't think the quad cores have hyperthreading, the new I7 might have though.

Oh right, if that's the case it seems strange that the option is configurable in the BIOS

It's normal for some cores to have most of the work still as most applications use 1 or 2 threads so can't utilise many cores. 1 thread is captive to a core so the load cannot be spread.

Cheers for that.

That could explain why two of my cores are always between 10C and 12C hotter than the other two cores!

I assume that in time, software will be written to take full advantage of quad core processors?

I believe that 8 core processors are currently being developed and that software will have to be written exclusively for these processors as well?

 

[Tute]

Yep. It's to do with the way the code is worked I believe. You can't simply take a single-threaded application and split it down multiple cores.

Windows is good at thread scheduling across many cores though. Using HT in Windows should give a boost.

 

[CurlyWhirly]

Windows is good at thread scheduling across many cores though. Using HT in Windows should give a boost.

I'll enable it in the BIOS and if it causes me problems, I can always disable it again

 

[russ0r]

I have Hyper Threading Technology disabled in the BIOS (it's off by default)

Would I gain performance by enabling it?

I'm wondering if it has anything to do with the fact that most of the time, even though I have a quad core processor, 2 of the cores seem to be doing most of the work whilst the other 2 cores are idle for most of the time

Could this be related to hyper threading being disabled or this normal for quad core processors?

I don't think much software has been written to take advantage of hyper threading thus far?

Yes, it will increase performance slightly on some applications.
It isn't supported on the Core architecture though. It has only just been re-implemented on i7 since the P4 days. Enabling it if you're using a core processor will probably make no difference.
Oh, and apparently it's very power hungry, so leave it turned off if you're on a laptop.

 

[CurlyWhirly]

Yes, it will increase performance slightly on some applications.
It isn't supported on the Core architecture though. It has only just been re-implemented on i7 since the P4 days. Enabling it if you're using a core processor will probably make no difference.
Oh, and apparently it's very power hungry, so leave it turned off if you're on a laptop.

I'm on a desktop PC but I'll leave it turned off if there's no benefit

By the way my processor is a Q9650

 

[Tute]

It won't make a difference - the Core arctitecture doesn't support it!

You'll need an i7 to see it working.

 

[CurlyWhirly]

It won't make a difference - the Core arctitecture doesn't support it!

You'll need an i7 to see it working.

Just as well I asked here then

 

[Lanz]

a lot of Xeons have Hyperthreading, and old P4s that still use s775. I guess its in the bios incase u plonk one of those in.