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Intel locks overclocking to K-series Haswell chips

Intel locks overclocking to K-series Haswell chips

Intel's new Haswell chips entirely lock overclocking to K-series parts, preventing non-K chips from even the minor adjustment to Turbo Boost bins possible in Ivy Bridge and Sandy Bridge parts.

Intel has confirmed claims that overclocking of Haswell processors will be limited exclusively to the K-series chips, with the standard families no longer able to have their performance boosted.

First reported by The Tech Report and since confirmed by an Intel spokesperson, the move sees the modest overclocking ability available to Turbo Boost-enabled Sandy Bridge and Ivy Bridge processors removed entirely in the Haswell family. While overclocking will still be supported by the higher-price K-series parts, including the Core i5-4670K and Core i7-4770K chips we've already reviewed, non-K parts will be locked at their stock clocks.

Officially, overclocking Intel's most recent Core chips has only ever been supported on the enthusiast-grade K-series parts with their unlocked multipliers. Those with the 'locked' models, however, soon discovered they were able to squeeze a little extra out of the chips by increasing the Turbo Boost 'bins' - multipliers that apply only during certain CPU activity, such as when only one or two of the chip's cores are loaded and temperature is below a pre-set level. While the primary multiplier is locked on non-K parts, it's been possible to increase the multipliers used by Turbo Boost across almost all Core-family parts that support the feature.

At least, up to Haswell.

Intel has confirmed that the ability to adjust Turbo Boost multipliers in non-K parts has been removed in Haswell, with those who want to twiddle with multipliers to get the best performance out of their hardware being pushed towards the K-series parts instead. While these will allow for multiplier adjustment, they also lack selected enterprise-oriented features - including support for transactional memory and VT-d virtualisation extensions - present in other models.

According to a statement released by Intel on the matter, the move is quite deliberate: the non-K-series parts, the company explains, are targeted at business and mainstream consumer users who shouldn't be fiddling around with multipliers in the first place. For enthusiasts who want such functionality, there's the K-series - so long as TSX-NI, VT-d and vPro support isn't required.

14 Comments

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GravitySmacked 14th June 2013, 10:30 Quote
Is anyone surprised by this?
Bob Andersson 14th June 2013, 10:31 Quote
That's weird. If VT-d is absent from the i7-4770K then it's no good to me. Are you absolutely sure about this? Can there possibly be an engineering reason or is Intel just playing silly beggars?
Gareth Halfacree 14th June 2013, 10:33 Quote
Quote:
Originally Posted by Bob Andersson
That's weird. If VT-d is absent from the i7-4770K then it's no good to me. Are you absolutely sure about this?
Completely sure: Intel's Ark page for the Core i7-4770K confirms the fact: while it supports VT-x extensions, it does not support VT-d.
phoenixck 14th June 2013, 10:40 Quote
I was sure that in previous gens it was the bclk that people tweaked, more specifically in haswell the strap. Certainly jj from asus has stated that if you really want you can adjust the strap on the non k parts.
Bob Andersson 14th June 2013, 10:43 Quote
Yep, I've Googled and it's true. No VT-d support means no i7-4770K for me. I guess the i7-4770 will do fine and as no overclocking means I don't need a top of the range motherboard, RAM or cooling I can up the budget for other stuff. Crazy decision on Intel's part. Maybe a GTX Titan just came into range!!!
Freemanator 14th June 2013, 13:21 Quote
Bob, what do you need VT-d support for?
Bob Andersson 14th June 2013, 13:58 Quote
High speed access to hardware for virtual machines. Not a particular issue for me right now but within the lifetime of the next build I expect it to be. Even so it's a close call and I fully accept that for many lack of VT-d support in the "K" series CPUs won't be a problem. I'm just thankful I found out in time. :)
AlienwareAndy 14th June 2013, 14:06 Quote
So they're not even allowing the 4 bins they gave on the Sandy and Ivy non K CPUs?

That's pretty terrible. Maybe the bclk can be used?
schmidtbag 14th June 2013, 14:10 Quote
I wonder if Intel's reasoning is because VT-d becomes unstable when OCing. Otherwise, disabling such a feature on a more expensive CPU really doesn't make sense. I'm sure Intel also doesn't like the idea of people buying overclockable desktop parts for server use, since you'd end up saving a lot of money on something that will last much longer.
RedFlames 14th June 2013, 14:13 Quote
The Skt 2011 processors -K and not [or are they all 'K' models?] have VT-d support, it's only the 1156/1150 ones that don't... so want Virtualisation and overclocking? SB-E/IB-E is what you want/need...

EDIT: Apparently the SB-E K series only support VT-d on the C2 stepping...

There is also the AMD option... iirc all their processors have AMD-v or whatever their vitualisation gubbinz is called...
Shirty 14th June 2013, 14:38 Quote
I think the lack of VT-d issue has been persistent on all K models since Sandy launched.
Bob Andersson 14th June 2013, 15:16 Quote
Quote:
Originally Posted by Gareth Halfacree
Completely sure: Intel's Ark page for the Core i7-4770K confirms the fact: while it supports VT-x extensions, it does not support VT-d.
Thanks for the quick response, Gareth. In asking the question I didn't mean to question your journalistic credentials: I was in shock! :)
rollo 14th June 2013, 15:40 Quote
It has shirty as they want you to buy a more expensive CPU or a none overclockable one.
Gareth Halfacree 14th June 2013, 16:27 Quote
Quote:
Originally Posted by Bob Andersson
Thanks for the quick response, Gareth. In asking the question I didn't mean to question your journalistic credentials: I was in shock! :)
Heh! I hadn't taken any offence, don't worry - I was just in a bit of a rush this morning so had to be a bit terse in my reply. It's the TSX-NI that I weep for: developers are hardly going to be rushing to implement transactional memory if half the processors don't support it...
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