Intel Prevents Overclocking of non-K Haswell Processors, and Strips Virtualization and TSX Features From K Parts

Subject: Processors | June 13, 2013 - 06:59 AM |
Tagged: tsx, overclocking, Intel, i7-4770k, haswell

First revealed at IDF Beijing, Intel's latest generation 4th Generation Core "Haswell" processors enjoy a refined architecture, improved processor graphics, an integrated voltage regulator (FIVR), and for the enthusiast crowd, new methods for overclocking.

In truth, the methods for overclocking Haswell are very similar to those used to overclock Intel's Sandy Bridge and Ivy Bridge processors. However, Intel has further unlocked the new Haswell CPUs. Enthusiasts can set an overclocked Turbo clockspeed, use additional base clock (BCLK) values (100 MHz, 125 MHz, and 167 MHz), and overclock the unlocked processor graphics core clockspeed and memory clockspeed (memory in 200 MHz or 266 MHz steps). The additional BCLK values allow for easy overclocks without putting the other subsystems (such as the PCI-E bus, GPU, and memory) out of spec, which is important for the PCI-E bus which needs to be close to 100 MHz for a stable system.

The following PC Perspective articles have further information on overclocking unlocked "K" edition Haswell processors:

Although Intel's overclocking reveal at IDF was fairly detailed, the company did not get into specifics on how overclocking would work on non-K chips.

On that note, the crew over at the Tech Report uncovered some rather disheartening facts such that the non-K edition Haswell processors will, essentially, be locked at stock speeds and not overclockable (they are slightly more locked down than previous generations).

While the K edition Haswell processors, such as the Core i7-4770K, will enjoy unlocked multipliers, unlocked GPU and memory clockspeeds, and additional BCLK options, the standard non-K chips (ie Core i7-4770, Core i5-4670, et al) will have locked multipliers, no Turbo Boost clockspeed overclocking, and will not be allowed to use the additional 125 MHz and 167 MHz BLCK options, which effectively makes overclocking these standard chips impossible. It may still be possible to push the BLCK up a few MHz, but without the extra stepping and gearing ratio options, the other component clockspeeds based off that same base clock are going to go out of spec and will become unstable fairly quickly as you try to push that BLCK up.

There is one saving grace for enthusiasts considering a non-K part, however. The standard non-K CPUs will have Intel's latest TSX extensions and enterprise virtualization technologies enabled.

Although quite the head scratcher, Intel has decided to disable TSX, vPro, and VT-d on the unlocked K edition chips. The TSX extensions are not widely used yet, but will provide a noticeable performance boost to future programs that do take advantage of them by allowing developers to essentially mark off sections of code that can be run independently, and thus increase the multi-threaded-ness of the application by running as much code in parallel across multiple cores as possible. Further, the vPro and VT-d features are used by virtual machine applications (with VT-d being more relevant to the consumer side of things).

In short, Intel has continued to lock down and artificially limit its chips, as many enthusiasts suspected would happen. Standard non-K Haswell processors are more locked down than ever, and even the premium unlocked K CPUs suffer with the (odd) removal of TSX and virtualization support. As Mr. Gasior points out, enthusiasts are going to be faced with an odd choice where they can either spend extra money on a premium K part that will overclock but is limited in other ways, or go with the lower cost part that has all of the ISA extensions and virtualization support turned on... but is not overclockable.

In my opinion, locking down the standard chips is one thing-- Intel needs to incentivize enthusiasts to go with the more expensive (~$25 premium) unlocked K processors some how -- but if those same enthusiasts are spending extra money for a premium chip, they should get all the features the accompanying non-K SKU has as well as overclocking.

What do you think about the artificial limitations placed on the various Haswell SKUs?

Source: Tech Report
June 13, 2013 | 07:19 AM - Posted by Anonymous (not verified)

This strange limiting of features of k series CPUs happened with sandy and ivy bridge as well. I can't believe people are just now figuring this out. Smh

June 15, 2013 | 02:49 AM - Posted by Ytazbddj (not verified)

When u rule the processor world this kind of limitation will follow. Same happens with Microsoft with their Windows 8 and Xbox One.

June 13, 2013 | 07:22 AM - Posted by Anonymous (not verified)

"In my opinion, locking down the standard chips is one thing-- Intel needs to incentivize enthusiasts to go with the more expensive (~$25 premium) unlocked K processors some how"

Yes, and in turn they lock down the K processors to convince enthusiasts to purchase the next Extreme Edition processors which will probably have vPro, VT-d and TSX. You can see this trend now as the 3770K does not have VT-d but the 3930K, for example, does.

June 13, 2013 | 07:44 AM - Posted by Anonymous (not verified)

So the question is: Do I purchase an H87 board with a non-K processor and save $100+ to put towards other items on my build?

I wasn't planning on overclocking, but wouldn't mind the flexibility - but why buy a Z87 board if you aren't going to overclock? I don't see it as a $25 difference. I see it as a $100 difference because of the MB - and $100 for the "maybe one-day" aspect of overclocking seems to be a premium that is too large.

June 13, 2013 | 08:24 AM - Posted by Anonymous (not verified)

I believe the H87 does not support TRIM in RAID 0, while the Z87 does. Whichever way you cut it, there is no complete package available unless you go for something like LGA 2011 or AMD.

I reserve the right to be wrong on this.

June 13, 2013 | 08:24 AM - Posted by DeadOfKnight

The review samples seem to do an OK job at overclocking, but if you read customer reviews you'll find that most of them can't get over 4.3 GHz on air stable. The "K" SKU leaves much to be desired. Honestly, I think the only good thing that comes with Haswell is the outstanding motherboard selection.

June 13, 2013 | 09:01 AM - Posted by jjcruz78

I think this way too bad Intel in the long run could loss big time. The more I read about Intel lately the more I want just good enough part from AMD, I think they will come. I'm tired of supporting a company that has lost their bearings and looks more anti consumer than ever.

June 13, 2013 | 09:11 AM - Posted by Bluejay (not verified)

I miss a competitive AMD...

June 13, 2013 | 09:39 AM - Posted by David Gilmore (not verified)

On June 1st they were bragging on all the new instruction sets etc. and those articles were about the 4770k - talk about misleading! AMD's new FX-9590 5 GHz chip may be stealing market share from Intel after this news. I guess we'll have to wait for Ivy Bridge Extreme for a decent CPU, that is if they don't screw it up as well.

June 13, 2013 | 04:32 PM - Posted by Fishbait

So not only are Haswell CPU's not very overclockable, but they also have some interesting features turned off? (I'm starting to lean more towards the "DIY is dying" crowd at this point *frown*)

A couple more generations and I'll be Forced back to AMD, although I loved them back in the day, it's still sad that this is how it happens.

June 14, 2013 | 06:04 AM - Posted by Nero576 (not verified)

If K-SKUs don't have VM capability, didn't Intel shoot itself in the foot? Why am i forced to choose between VMs or Overclock?

June 14, 2013 | 06:59 AM - Posted by Anonymous (not verified)

Please correct me if I am wrong. Don't VMWare Workstation and Hyper-V require VT-d?

June 14, 2013 | 07:09 AM - Posted by Anonymous (not verified)

Answered my own question. It requires VT-x which the K versions support. VT-d is direct IO which is not needed for VMware and Hyper-V to run.

June 14, 2013 | 09:22 AM - Posted by Virtuous (not verified)

These are once again actions of a monopoly.

June 20, 2013 | 11:24 AM - Posted by Totally PC Bonkers (not verified)

If the K's have things stripped out and then overclocking allowed they should be the same price as the non-K's as in the end it balances out.

The problem is AMD has nothing to compete with Intel at the top of the ranges so Intel can do what they want and get away with it!

August 4, 2013 | 05:16 PM - Posted by sharks,snakes and greedy (not verified)

three words: fuck you intel
i was on the verge of getting the 4930k as it had like 15% performance and arround 8% cheaper but not any more you fuckin douchbags, with your sneaky marketing tactics i bet i'd be safe with amd as they will kick your asses.. mark my words, decided to get fx-8350 and switch to 9590 later or a better one in time

January 2, 2014 | 07:26 AM - Posted by Hikari (not verified)

Big disappointment.

For almost 10 years I always overlocked my PCs. But when I bought my SandyBridge 2600K I saw no need for OC, still I chose 2600K in case I decided to overclock it in the future.

It never happened. Most my apps keep it idle most of the time, AVC decoding barely requires 20% usage of 4 cores with HT threads remaining idle, and games also bottleneck in my 560 Ti and leave CPU cool.

That's it, I'm moving to i5 non-K in next upgrade. That upgrade will result in drop of CPU performance, but I haven't needing it at all.

The question mark comes in, when to upgrade? Haswell sucks, Broadwell will be out only in 2015, Skylake may come focusing on Smartphone and not PC. I might wait till 2020 for Skymount and 64GB DDR4.

March 11, 2014 | 06:21 PM - Posted by Anonymous (not verified)

I don't know why so many are so obsessed with overclocking the top cpu. There isn't a program that needs that speed. Its all just for bragging.

July 12, 2014 | 10:18 PM - Posted by Anonymous (not verified)

Waht pisses me off is that they don't write this information in big letters so that you know what is happening before you buy it! Not everyone has time to sour all the small print to find out that Vt-d is not supported and why it matters!

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