Review Index:

The Intel Core i7-4790K - Devil's Canyon Review and Overclocking

Author: Ryan Shrout
Subject: Processors
Manufacturer: Intel

Overclocking Experiences and Temperatures

Impressive out of the box performance aside, the other big mystery is how much the new thermal interface and capacitors on Devil's Canyon would change the way Haswell overclocks. I can say, based on my experience with this chip and after talks with motherboard vendors that have used quite a few more engineering samples of the Core i7-4790K, the answer is likely not very much.

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Temperatures during load of Core i7-4770K at stock speeds

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Temperatures during load of Core i7-4790K (DC) at stock speeds

Both processors were run on the ASUS Z97-Deluxe motherboard with a Corsair H80 self-contained water cooler.

Take a look at the two temperature readings above. Operating at 3.5-3.7 GHz, the 4770K was measuring about 53-55C. While that isn't a bad temperature range, the Core i7-4790K, running at 4.0 GHz, was only measuring at 50-51C. Seeing a couple of degrees improvement in load temperature with an increased clock speed is a welcome change and can be attributed to the improvements Intel designed into Devil's Canyon.

Let's see how the processor overclocks and what that might change. 

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The overclocking process with the Core i7-4790K is identical to that of other Haswell parts.  The theory has been that, thanks to these improved thermals, we should see improved scaling. That did not happen for me. My peak overclock for all cores was 4.7 GHz running at 1.36v and no amount of added voltage or changes to the overcurrent protection or cache voltages, seemed to matter. I could not reach 4.8 GHz for a standard stability run. 

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To be clear, even for a standard Haswell processor, this result is pretty average. Setting your core voltage to 1.36v is pretty damn high and I've had much better luck with our single Core i7-4770K, as you'll see below. By itself, this does not mean that Devil's Canyon is a worse overclocker, or that it isn't a better overclocker, just that the single sample we were provided didn't show the improvement

On this same motherboard, on this same day, I was able to take a Core i7-4770K ES processor and hit 4.8 GHz stable with a voltage of just 1.25v. Clearly THAT result is well above average and could be considered one of the better Haswell parts I have seen. So how did the temperatures compare in our best overclocks with the two CPUs?

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Temperatures during load of Core i7-4770K at 4.8 GHz

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Temperatures during load of Core i7-4790K at 4.7 GHz

Interesting stuff. Even though I wasn't able to get higher than 4.7 GHz, the limit does not appear to be temperature on my Core i7-4790K, just crappy luck. Under load with a voltage of 1.36v, temperatures on Devil's Canyon didn't go past 84C. On the other hand, the original Haswell part hit 91C with a lower voltage (1.25v) and higher clock speed (4.8 GHz). 

With just a single CPU sample in my hand its hard to make any definitive statement, but my guess is that the changes Intel made on the Core i7-4790K did in fact have a positive effect on the temperature of the core. It just so happens that our sample from Intel didn't perform as highly as we might have hoped, purely by chance. I am hoping to pick up another 4790K to do some more testing but even then, with a sample size of two, we will be depending on the community to really make the final decision on the benefits of Devil's Canyon.

June 7, 2014 | 01:35 AM - Posted by Anonymous (not verified)

"It's not "budget" but most people's standards but getting this kind of performance with a $339 CPU helps everyone and Intel's good will gesture to the community at least indicates that the lack of competition on the high-end of the market isn't totally damning us all."

There is something wrong with this sentence.

June 7, 2014 | 10:07 AM - Posted by Ryan Shrout

Fixed the typo, thanks!

June 7, 2014 | 01:45 AM - Posted by JxcelDolghmQ (not verified)

Thanks for the review. Decent pricing, for an Intel part, but they do not seem to be binning these chips for overclocking like some people were hoping or expecting. Funny to see the 8350 still topping the performance per dollar charts despite its age and lack of price drops. Really demonstrates the lack of progress in the higher end of late.

Couple of potential typos:
On the Test Setup page, you list the A10-5800K but it does not appear in any of the benchmarks.
In the conclusion, second to last paragraph, you write: "It's not "budget" but most people's standards", I think you meant "by most people's standards".

June 10, 2014 | 11:14 AM - Posted by Patrick P (not verified)

Eh, the performance for dollar rankings have never included the average power usage in the calculation. In reality 4690 > 8350 for perf/$ in the long run.

June 7, 2014 | 02:22 AM - Posted by renz (not verified)

so clock for clock how much improvement we are going to see from sandy bridge to this new line up?

June 7, 2014 | 02:45 AM - Posted by JxcelDolghmQ (not verified)

Same as Sandy to Haswell, IPC is not any better on these than regular Haswell.

June 7, 2014 | 10:08 AM - Posted by Ryan Shrout

Correct, it's the exact same architecture, just higher clocks (than we have seen before) and new TIM and added caps.

July 26, 2014 | 04:39 AM - Posted by Carolyn (not verified)

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June 7, 2014 | 03:17 AM - Posted by Havor (not verified)


Why do you use the X series when comparing price performance ratio's of S2011 CPUs, hell i would not even recommence a S2011 CPU for 95% of the people that buy them.

And i know my 3930K + R4E dose not have the best price performance ratio, but using 3970X and 4960X CPUs that no one in his right mind would buy over the x930K series is just muddying the waters.

June 7, 2014 | 10:09 AM - Posted by Ryan Shrout

Well, to be honest, these are the parts we have in-house for testing.

But the comment is noted and we'll try to include more of the product range when doing future reviews. Maybe for Haswell-E, for example.

June 7, 2014 | 04:16 AM - Posted by Martin Trautvetter

I really like that Intel went with a much higher default clock on this one, not just a 100 MHz bump, and agree with your assessment that that makes the 4790K a great choice even if you never plan to overclock. 400 MHz extra for just $25 over the regular 4790? Who wouldn't buy the K?

Interesting results, though the (sometimes) stilted scaling and conspicuously higher idle power consumption look a bit odd. Hope the latter will be fixed by newer UEFIs, and is not an inherent trait of DC Haswells!

I wouldn't worry about the pricing, the 4770K will be sold off, with the 4790K replacing it at the same price soon.

Personally, I can't wait to see when (if?) Gigabyte updates my Z87's UEFI to include DC support.

June 7, 2014 | 04:51 AM - Posted by arbiter

if they don't then its gigabyte that decided to, I have an Asus Z87 board and they have bios for DC cpu out.

June 7, 2014 | 08:27 PM - Posted by John H (not verified)

The K parts miss some of the virtualization features the non-Ks have..

June 8, 2014 | 07:29 AM - Posted by Martin Trautvetter

While that was true for the old Ks, VT-d and TSX-NI are enabled on the new DC Ks:,80806,75123

BTW: How cool is it that the ARK-references for the i7 Haswell refreshes could be read as "eighty-eighty-six" and "eighty-eighty-seven"? /geek-out ;)

June 8, 2014 | 04:16 PM - Posted by Anonymous (not verified)

Wow that's good to know.

June 9, 2014 | 07:03 PM - Posted by John H (not verified)

That is good to know! I want a i666 inside my system now!

June 7, 2014 | 05:54 AM - Posted by Anonymous (not verified)


What would your temps on the 4770k have been had you put it at 4.7GHz (the same as the 4790k) and reduced the voltage to the bare minimum to sustain that frequency?

If the temperatures in that case would be in the 70's or 80's, which is warm but still acceptable, I really don't see the point in this product from an overclocking prospective.

June 7, 2014 | 10:10 AM - Posted by Ryan Shrout

I would agree with that statement if my overclocking results were to be the definitive results, but it is possible that the 4770K that I got happens to be a GREAT overclocking part and the 4790K I got happens to be a poor overclocking part. There is still a lot of luck in this business.

June 7, 2014 | 03:39 PM - Posted by Anonymous (not verified)

The point is that they cost the same, but the 4790k has better thermal properties, which is huge for overclocking. Even if it can't clock higher, it can reach the same speeds with much more stability without requiring a risky delid.

June 7, 2014 | 07:48 AM - Posted by CB (not verified)

Ryan, any chance you could tell us what the fastest stable OC you got was without a voltage bump? It'd be interesting to see that OC temp without voltage increases...

June 7, 2014 | 10:11 AM - Posted by Ryan Shrout

The only data I have on that is at 1.2v, which is where I started overclocking testing. On that, I could hit 4.5 GHz, but no more.

June 7, 2014 | 10:47 AM - Posted by Robogeoff (not verified)

"Temperatures during load of Core i7-4970K at 4.7 GHz"

4790K or 4970K?

I would think it weird for this Haswell refresh to get a model number that's higher than my Ivy-E 4930K.

June 7, 2014 | 01:52 PM - Posted by Morry Teitelman

Fixed, thanks for pointing that out...

June 7, 2014 | 10:52 AM - Posted by polu (not verified)

Can you pls cut the IHS and see if there is a weak TIM or is it soldered as SB, pls?

June 9, 2014 | 04:40 AM - Posted by Earnest Bunbury (not verified)

YES, er... YES!

June 7, 2014 | 11:36 AM - Posted by Anonymous (not verified)

Could you run tests using a z87 motherboard also? Would really like to see if there are any limitations on using the new chips with a z87 board.

June 7, 2014 | 11:51 AM - Posted by geekthem (not verified)

June 7, 2014 | 12:04 PM - Posted by Anonymous (not verified)

Why am I not seeing 8core cpu for decent price yet.

fuk this shit, fuk intel, goto devil canyon hell.

June 7, 2014 | 04:40 PM - Posted by Anonymous (not verified)

Hopefully they skip Broadwell on the PC. Can't see them releasing Broadwell this year if they're dropping a Haswell "Refresh" this late. Not to mention it's going to be a disappointment for desktops anyways.

Can't even get excited for the Haswell 8 core part being that it's only for the $1,000 model. My fricken $500 i7 3930K is an 8 core part with 2 cores disabled. No reason why they shouldn't offer an 8 core part for the $500 range either. Intel being Intel.

June 8, 2014 | 12:49 AM - Posted by Humanitarian

Lel, "[Intel]8core cpu for decent price"

Are you high?

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