I am in the middle of building a Sandy Bridge system based on an Asus P8Z68-V Gen3 and an i7 2600K. I use Pro Tools 9 (10 soon).

I have read numerous reports online about Hyperthreading and if I should turn it on or off in the Bios... but all of them give conflicting reports!

Any of the experts here have any concrete advice for me, based on experience and/or knowledge?

As far as I know, turning off hyperthreading only solves problems in a very small number of cases (some of my ancient PCI soundcards don't like it, for example!). I'd leave it on until you can positively identify it as a problem — if you have a problem in the first place!

Cheers,

Chris

Indeed, what he said.

A few software firms still state that it may be optimal to turn it off, but I suspect this is more in order to minimize potential support calls more than anything else. The last time I saw hyperthreading having a seriously negitive effect on a sequencer was probably back on the P4's and these days the difference in having it on and off can be as much as 50% or 60% performance increase, so well worth keeping it on.

--------------------
ScanProAudio & 3XS Audio Systems
ScanProAudio Blog

Thanks Chris, thanks Pete...

one extra question:
If Hyperthreading does eventualy prove to be a problem would then just switching it off in the Bios be enough or would I need to reinstall windows and everything from scratch?

Thanks again.

The only time I've ever had to do that was with some Creamware Scope cards (on XP, with their very old software and drivers — on Win 7 and with the new software they work absolutely fine with HT, on one of my systems at least).

I'd say it's such an unusual thing to have to do that it's worth 'risking' it and keeping it enabled.

Cheers!

Chris

Quote El Sid:

---

If Hyperthreading does eventualy prove to be a problem would then just switching it off in the Bios be enough or would I need to reinstall windows and everything from scratch?

---

Nope, you can turn HT on and off whenever you wish in bios and it won't require any sort of reinstall of the O.S.

--------------------
ScanProAudio & 3XS Audio Systems
ScanProAudio Blog

Great.

thanks again.

Is Hyperthreadiong synonymous with that AHCI/AHCP - can't remember what the acronym is but think it one of the 2 I have written here

Related in some way, I think... I definitely remember having problems with a specific PC configuration that was solved by disabling HT in the BIOS and then reinstalling Windows XP, and AHCI (I think) was the culprit!

That was ages ago, mind, and as I said above I'd be very surprised if it caused a problem on a modern rig.

Cheers!

Chris

I tested this last year on the 2600k. Turning hyperthreading off had the effect of turning an i7 into i5 level of performance, approximately a 20-30% reduction in performance. If you turn it off, you might as well have bought an i5.

--------------------
www.theautobots.com / www.scan.co.uk

Very true

Hyperthreading is well worth having with nearly all software - from the depths of my memory only Gigastudio had problems with it when it was first released by Intel


Martin

--------------------
YewTreeMagic

Quote Korff:

---

Related in some way, I think... I definitely remember having problems with a specific PC configuration that was solved by disabling HT in the BIOS and then reinstalling Windows XP, and AHCI (I think) was the culprit!

---

Perhaps you were thinking of 'ACPI'?

For the record, 'AHCI' relates to SATA interface mode and has nil to do with HT, while 'ACPI' is a BIOS system auto-configuration mode which is necessary for HT.

=Goddard
(Not trying to set a record, just to set the record straight)

Yup, that's the badger!

Quote El Sid:

---

I have read numerous reports online about Hyperthreading and if I should turn it on or off in the Bios... but all of them give conflicting reports!

---

This is because most people babbling online are clueless fules with no concept of rigour or how to source proper facts from reliable documentation

Quote El Sid:

---

Any of the experts here have any concrete advice for me, based on experience and/or knowledge?

---

I'd take the view that hyperthreading is a long-established feature of the operating system/processors in Windows PCs, and if it makes your software crash then that software is buggy rubbish, and you should use better software.

--------------------
~~~ A weasel hath not such a deal of spleen as you are tossed with! www.feline1.co.uk ~~~

> A few software firms still state that it may be optimal to turn it off, but I suspect this is more in order to minimize potential support calls more than anything else. The last time I saw hyperthreading having a seriously negitive effect on a sequencer was probably back on the P4's and these days the difference in having it on and off can be as much as 50% or 60% performance increase, so well worth keeping it on.

The last time I saw it was last week when a project would simply not run at a low latency with hyper threading enabled.


> This is because most people babbling online are clueless fules with no concept of rigour or how to source proper facts from reliable documentation

Indeed.

> I'd take the view that hyperthreading is a long-established feature of the operating system/processors in Windows PCs, and if it makes your software crash then that software is buggy rubbish, and you should use better software

He didn't ask if it made it crash, just whether it was better on or off. Hyperthreading usually results in sizeable performance gains, but at low latencies it can have a detrimental (sometimes extremely) effect on performance.

Just wanted to get back to you all on this.
I built the PC, of course with Hyperthraeding on, and it works like a dream. Many thanks for all the advice here.

Just to let anyone know who might be building a similar setup: in the Asus bios I disabled Eist, Turbo mode, C1E and the High Precision Timer as I had read suggested. The PC ran very well but I noticed the CPU ratio fluctating wildly and the Audio Latency Utility being around 50-75. I then disabled the C3 and C6 Reports in the bios as well and that got everything runing even better. CPU sticks then at the full ratio and my Latency came right down to 10-15.
Idle Temps at 38-40° (its warm here at the moment) and at 54-56° after Prime95 for an hour, all in a silent case.

Thought I should mention this in case it might help anyone.

Thanks again.

Hi, just a quick note

Quote:

---

Just to let anyone know who might be building a similar setup: in the Asus bios I disabled Eist, Turbo mode, C1E and the High Precision Timer as I had read suggested

---

I wouldn't disable Turbo Boost, check the performance with and without and check your DPC latency figures as well, should give you a performance boost under heavy load when enabled.

--------------------
Say hello on Facebook www.facebook.com/CarillonAudioSystems