HT ever a bad thing?

[anxiousinfusion]

Are there any scenarios where hyperthreading would hurt performance or be undesirable? Or is hypertheading a good feature in generally all aspects?

 

[gamerk316]

Not usually. Back when first implemented on the Pentium 4, there were some instances where depending on where threads were allocated, the HT core could become a bottleneck and reduce performance, but even then, that was rare. In todays environment, there is no reason to turn HT off, and I challenge anyone to find a case where HT causes a performance drop.

 

[geofelt]

Are there any scenarios where hyperthreading would hurt performance or be undesirable? Or is hypertheading a good feature in generally all aspects?

It is generally good.

I have a 2600K and have turned hyperthreading off. My reasoning was that my workload(games) did not use more than four threads.
I think that with less resource involved it is easier to overclock without hyperthreading.
I was an early adopter, and the price premium over a 2500K was not a show stopper. I also did not know(and still don't) how much value to place on the extra cache.
In retrospect, the 2500K would have been plenty.
It is also not clear to me how well the OS uses hyperthreads, and which tasks are assigned to them.

 

[simon12]

I would guess on the game benchmarks where the 2500 beats the 2600 are because of hyperthreading (as its unlikely the extra cache or the extra clock speed) but its only 1-2% ish. Hyperthreading does produce more heat so as already stated this may hamper overclocking but if you have reasonable cooling very little.

 

[anxiousinfusion]

Not usually. Back when first implemented on the Pentium 4, there were some instances where depending on where threads were allocated, the HT core could become a bottleneck and reduce performance, but even then, that was rare. In todays environment, there is no reason to turn HT off, and I challenge anyone to find a case where HT causes a performance drop.

Understood... I was doing some of my own research and stumbled upon the exact debates which you speak of (involving the Pentium 4). I'm glad to hear that things have changed.

And since I like my hardware stock, the extra heat should be no problem. Thank you all!

 

[anxiousinfusion]

Best answer selected by AnxiousInfusion.