Sign in with
Sign up | Sign in
Core i7-4790K Review: Devil's Canyon Tantalizes Enthusiasts
By ,
1. Intel Core i7-4790K: Devil's Canyon Is For Enthusiasts

Man. I just realized almost one year has passed since I last wrote about Intel as a desktop processing company. And even then, the piece was Intel Core i7-4960X Review: Ivy Bridge-E, Benchmarked, about a slight evolution to a platform that launched nearly three years ago (X79 Express, in case your memory is rusty). That’s a pretty good indication of the extent that Intel was overlooking our enthusiast segment.

Actually, I’m not being entirely fair. Intel is running short on competition, after all. AMD's processor wing is really what's struggling to stay relevant amongst performance-hungry power users. As a result of the disappointing stagnation, I end up writing stories like The Core i7-4770K Review: Haswell Is Faster; Desktop Enthusiasts Yawn. In that piece, I was hard on the Core i7-4770K. The same went for my coverage of Core i7-3770K. Neither mainstream flagship gave you a compelling reason to upgrade. And it didn’t help that the shift from Z77 to Z87 to Z97 Express was pretty boring, too.

The good news is that Intel is listening.

Now I’m sitting here, in the lab, with the Core i7-4790K in front of me. As the CPU’s name suggests, this is still Haswell on an LGA 1150 interface. It’ll even drop into existing Z87-based motherboards, if your vendor of choice is being diligent about updating firmware. What’d Intel do to make the -4790K more enthusiast friendly, though?

Meet The Core i7-4790K

To begin, it addressed the one complaint that drove some power users and certain system builders to de-lid their CPUs: modest thermal transfer between the processor die and integrated heat spreader. We don’t know much about the “Next-Generation Polymer Thermal Interface Material” Intel is now using on its Devil’s Canyon parts. But we do know Intel worked uncharacteristically fast to implement it. In fact, the speed at which the company moved is cited as one of the reasons it couldn’t switch back to the solder that figured so prominently in Sandy Bridge overclocking successes.

The bottom of Core i7-4790K also features additional capacitors that Intel says help smooth power delivery to the processor die.

Those modifications come together, enabling a replacement for Core i7-4770K that drops into the same LGA 1150 interface. Vital specifications are very much similar; you get four physical cores able to address eight threads through HT technology, 8 MB of shared L3 cache, DDR3 memory support that officially tops out at 1600 MT/s, the same old HD Graphics 4600 engine, and a 16-lane PCI Express 3.0 controller.

Core i7-4790K operates at a base 4 GHz, though, and, in stock form, accelerates up to 4.4 GHz through Turbo Boost technology. This pushes the processor’s thermal ceiling up to 88 W (from 84).

You can expect the Devil’s Canyon parts to work in 9-series motherboards. However, Intel says board vendors may also update the firmware on their 8-series platforms.

2. Overclocking Core i7-4790K And TIM Performance

When I first started writing for Tom’s Hardware, I was all about pushing peak overclocks at settings I knew wouldn’t last long. Anything for those big numbers, right?

Over the years, I’ve heard from too many readers with processors and graphics cards that worked great six months ago, but aren’t stable at stock settings anymore. Now, I feel that it’s more important to dial in sustainable clock rates, enjoyable under any workload. When I talk to system builders (the guys who want to overclock, but also have to honor a warranty on their configurations) the discussions get more honest and I figure out which settings are expected to hold up over time.

Core i7-4770K runs all four cores at 3.5 GHz and can get up to 3.9 GHz through Turbo Boost. Beyond those clock rates, the first batch of retail CPUs was inconsistent. Most were solid around 4.3 GHz. A great many hit 4.4 GHz. Only a few were capable of 4.5 GHz. Not surprisingly, I ended up with a sweet sample able to do 4.7 GHz. That certainly wasn’t the norm, though.

With Core i7-4790K, Intel smartly exploits much of the headroom enabled by its more effective TIM and stable power delivery right out of the box. That’s where you get a four-core 4 GHz frequency able to jump up to 4.4 GHz in lightly threaded workloads. There’s no shame in an extra 500 MHz - particularly when you consider that Core i7-4790K sells for the same price as the 4770K (it’s on pre-order right now for $340).

Of course, we still want to get more out of the processor, if we can. At a core voltage of 1.25 V (which is where we’ve settled for safety on overclocking Haswell) fully threaded workloads are fine at 4.4 GHz, while 4.7 GHz was the peak in tests like iTunes and LAME. That's where we ran our benchmarks. Pushing up to 1.31 V, though, it’s possible to run through our suite at 4.6 GHz, with single-threaded clock rates up to 4.8 GHz.

Most notable, perhaps, is that the Core i7-4790K doesn’t seem to suffer from the same quick saturation of heat that our 4770K samples experience. Rather than slamming into a throttling condition (usually brought on by too much voltage triggering untenable temperatures), we ran into the sort of crashes you can typically stave off by supplying more power to the CPU. A Prime95 burn-in might have been more troublesome, but the benchmarks we ran weren’t limited by the temperatures we were seeing.

Throughout the testing, you’ll see our stock and overclocked performance results at sustainable clock rates, representing a range of frequencies based on the test being run.

The Impact Of Intel's NGPTIM

Before we get to the bulk of our numbers, I wanted to isolate the impact of Intel's Next-Generation Polymer Thermal Interface Material. I took the Core i7-4770K and -4790K, dropped them both into MSI's Z97 Gaming 7 motherboard, applied the same 1.275 V, and manually dialed in a 4.2 GHz clock rate. For the 4770K, that's an overclock. For the 4790K, that's the factory-shipped four-core Turbo Boost setting.

Temperatures were logged in one second intervals for all four cores on each CPU, and I charted their average as soon as each processor hit 100% utilization in our 3ds Max 2013 rendering workload (in other words, this data is generated using a real-world metric).

At the same voltage and pegged at the same clock rate, Intel's Core i7-4790K runs about 6 °C cooler. Interestingly, this delta doesn't change over time (at least, not in the relatively short segments we logged thermal performance). From pretty much the moment load is applied to the processor until it's lifted, roughly six degrees separate their readings.

3. How We Tested Core i7-4790K

Architecturally, Core i7-4790K is the same as its predecessor. If you want to know more about Haswell, check out The Core i7-4770K Review: Haswell Is Faster; Desktop Enthusiasts Yawn.

Really, our purpose today is comparing the previous flagship to Intel’s most recent effort. With that in mind, I ran both CPUs in stock and peak-overclocked form through the newest build of our benchmark suite.

Test Hardware
ProcessorsIntel Core i7-4790K (Haswell) 4.0 GHz (40 * 100 MHz), LGA 1150, 8 MB Shared L3, Hyper-Threading enabled, Turbo Boost enabled, Power-savings enabled

Intel Core i7-4770K (Haswell) 3.5 GHz (35 * 100 MHz), LGA 1150, 8 MB Shared L3, Hyper-Threading enabled, Turbo Boost enabled, Power-savings enabled
MotherboardMSI Z97 Gaming 7 (LGA 1150) Intel Z97 Express, BIOS 1.3
Memory
G.Skill 16 GB (4 x 4 GB) DDR3-1600, F3-12800CL9Q2-32GBZL @ DDR3-1600 at 1.5 V
Hard Drive
Samsung 840 Pro 256 GB, SATA 6 Gb/s
Graphics
Nvidia GeForce GTX Titan 6 GB
Power Supply
Corsair AX860i, 80 PLUS Platinum, 860 W
Heat Sink
Noctua NH-U12S, Fan set to 100% duty cycle
System Software And Drivers
Operating System
Windows 8 Professional x64
DirectX
DirectX 11
Graphics DriverNvidia GeForce Release 337.88

Obviously, the overclocks on both processors represent a limited look into what you might get in the wild. What I can say, though, is our Core i7-4770K is a retail-purchased processor that I snagged from Newegg (and not the press sample we were using previously, which hit 4.7 GHz). It better represents what many of our readers report: using strong air cooling and 1.275 V, four cores are stable at 4.2 GHz, with more lightly-threaded workloads running up to 4.5 GHz. It’s hard to apply significantly more voltage and not run into thermal issues, so we tend toward settings that (ideally) won’t do as much damage to the CPU over time.

My Core i7-4790K is a press sample. Nevertheless, it’s not an outrageous overclocker. I was able to get it up to 4.6 GHz across all four cores using 1.31 V, with single-threaded tasks jumping up to 4.8 GHz. In this case, it appears possible to apply higher voltages to dial in a more stable/higher overclock. However, we’re still apprehensive about going much higher than 1.3 V on Intel’s 22 nm process.

All tests are run on MSI's Z97 Gaming 7 motherboard running the latest 1.3 firmware. We populated all four of its memory slots with 4 GB modules, dropped in a GeForce GTX Titan graphics card, and hooked up Samsung's 840 Pro SSD. 

Benchmark Configuration
Adobe Creative Suite
Adobe After Effects CCVersion 12.0.0.404 x64: Create Video which includes three Streams, 210 Frames, Render Multiple Frames Simultaneosly
Adobe Photoshop CCVersion 14.0 x64: Filter 15.7 MB TIF Image: Radial Blur, Shape Blur, Median, Polar Coordinates
Adobe Premeire Pro CCVersion 7.0.0, 6.61 GB MXF Project to H.264 to H.264 Blu-ray, Output 1920x1080, Maximum Quality
Audio/Video Encoding
iTunesVersion 11.0.4.4 x64: Audio CD (Terminator II SE), 53 minutes, default AAC format 
LAME MP3Version 3.98.3: Audio CD "Terminator II SE", 53 min, convert WAV to MP3 audio format, Command: -b 160 --nores (160 Kb/s)
HandBrake CLIVersion: 0.9.9: Video from Canon EOS 7D (1920x1080, 25 FPS) 1 Minutes 22 Seconds
Audio: PCM-S16, 48,000 Hz, Two-Channel, to Video: AVC1 Audio: AAC (High Profile)
TotalCode Studio 2.5Version: 2.5.0.10677: MPEG-2 to H.264, MainConcept H.264/AVC Codec, 28 sec HDTV 1920x1080 (MPEG-2), Audio: MPEG-2 (44.1 kHz, 2 Channel, 16-Bit, 224 Kb/s), Codec: H.264 Pro, Mode: PAL 50i (25 FPS), Profile: H.264 BD HDMV
Productivity
ABBYY FineReaderVersion 11.0.102.583: Read PDF save to Doc, Source: Political Economy (J. Broadhurst 1842) 111 Pages
Adobe Acrobat XIVersion 11.0.0: Print PDF from 115 Page PowerPoint, 128-bit RC4 Encryption
Autodesk 3ds Max 2012 and 2013
Version 14.0 x64: Space Flyby Mentalray, 248 Frames, 1440x1080
BlenderVersion: 2.68a, Cycles Engine, Syntax blender -b thg.blend -f 1, 1920x1080, 8x Anti-Aliasing, Render THG.blend frame 1
Visual Studio 2010Version 10.0, Compile Google Chrome, Scripted
File Compression
WinZipVersion 18.0 Pro: THG-Workload (1.3 GB) to ZIP, command line switches "-a -ez -p -r"
WinRARVersion 5.0: THG-Workload (1.3 GB) to RAR, command line switches "winrar a -r -m3"
7-ZipVersion 9.30 Alpha: THG-Workload (1.3 GB) to .7z, command line switches "a -t7z -r -m0=LZMA2 -mx=5"
Synthetic Benchmarks and Settings
3DMark 11
Version: 1.0.5
PCMark 8
Version: 2.0, Creative (Conventional)
4. Results: Synthetics

Comparing the 3DMark suite score to the Graphics and Physics results shows that CPU performance is what moves the dial. Most notably, a stock Core i7-4790K is faster than our overclocked Core i7-4770K. Given that this test is well-threaded, and both configurations are set up for four-core Turbo Boost settings of 4.2 GHz, the outcome is unexpected. It is something you'll see happen consistently through the rest of our suite, though.

I picked PCMark 8's Creative suite for our little exploration in light of its emphasis on media and content creation (specifically, Web browsing, photo editing, video editing, gaming, and video chat). There are two versions of the benchmark: Conventional and Accelerated, the latter of which employs OpenCL-based acceleration. Because I specifically want to isolate the host processor, though, and not lean on the GeForce GTX Titan in our test machine, these numbers reflect the Conventional run.

The biggest speed-up comes from overclocking a Core i7-4770K from its stock 3.5 GHz up to 4.2 GHz. However, the Core i7-4790K wants to run at 4.2 GHz in its stock form, too, and it yields a bit of extra speed in the process. Pushing up to 4.4 GHz across all four of the 4790K's cores registers a a small speed-up, and you'd expect to see similarly subtle increases as you push the CPU harder.

The results from each processor are reflected in kilonodes per second. A node is a position on the chessboard. So, in the case of Core i7-4790K, Fritz evaluates more than 16,000 thousand nodes per second, or 16 million. In comparison, a Core i7-3930K, operating at its stock frequencies, returns more than 18,000 kN/s, and the Core i7-4960X approaches 20,000. Those CPUs get their advantage from six physical cores, even though they employ older architectures.

5. Results: Content Creation

It's difficult to get a sense of scale from four comparison points. However, if we were to add, say, AMD's Kaveri-based A10-7850K to the chart, you'd see a workload completion time in 3ds Max 2012 of 3:46. That's 1:45 longer than a stock Core i7-4790K. In the context of our battle between Haswell-based processors, though, the biggest benefit again comes from overclocking the stock Core i7-4770K. Of course, a stock 4790K is just a bit quicker, and applying some extra clock rate to the new CPU helps even more. 

For the sake of comparison, a Core i7-4790K, overclocked, is almost as fast as a Core i7-3930K at its default clock rate in this well-threaded application.

Expect steady improvements as you step from Core i7-4770K at its factory frequencies to the same CPU overclocked to a Core i7-4790K. Blender easily taxes all four cores on both processors, so the overclocked chips are operating at 4.2 and 4.4 GHz, respectively.

Vegas Pro 12 is set up to exploit our GeForce GTX Titan through OpenCL. Despite the fact that we're offloading some of the host processing workload, CPU performance does still matter, as only some of the rendering process is accelerated.

6. Results: Adobe CC

Every test we've run thus far is optimized for multi-core processors, which means more often than not, power users who run these titles are going to want six-core Ivy Bridge-E-based platforms when budget allows. You'll still get excellent performance from an overclocked Core i7-4790K though. The improvement going from stock Core i7-4770K to tuned -4790K is more than 14 percent.

After Effects is also threaded, though the workload we throw at it already finishes so quickly on a Core i7-4770K that there's not a ton of room for improvement. As a percentage, you can still expect a roughly 13 percent speed-up going from stock 4770K to overclocked 4790K.

As you no doubt already know, we run two Photoshop benchmarks. The first consists of filters optimized for multi-core CPUs. The second employs filters that exploit graphics processing through OpenCL. In both cases, Intel's Devil's Canyon serves up quantifiable benefits.

7. Results: Productivity And Media Encoding

Tuning Core i7-4770K up to 4.2 GHz (using the four-core Turbo Boost setting) has a nearly 10 percent impact in our FineReader OCR workload. From there, the stock Core i7-4790K shaves off a couple of seconds more, while overclocking further whittles away at the completion time.

Same story in Visual Studio. This time around, the overclocked 4770K and stock 4790K nearly tie, which is the outcome we'd expect from two processors able to push four cores at a consistent 4.2 GHz. Nudging the clock rate up to 4.4 GHz across four cores gives Devil's Canyon an additional edge.

This is the only page with single-threaded tests, but TotalCode Studio isn't one of them. The bump you get from overclocking Core i7-4770K is easily replicated (and then some) by a stock Core i7-4790K.

The same goes for HandBrake, though the performance improvement is even more pronounced. From stock 4770K to stock 4790K, we report an almost 11 percent boost.

From the factory, a Core i7-4770K jumps as high as 3.9 GHz with one core active while the 4790K gets up to 4.4 GHz. That 500 MHz difference translates to an improvement of almost 12 percent. Pushing Devil's Canyon's clock rate up to 4.7 GHz knocks another couple of seconds off of the completion time.

Our iTunes test is similarly set up to utilize one core. The percentages work out to be fairly similar to LAME: expect double-digit gains from the frequency headroom freed up by more effective cooling.

8. Results: Compression Apps

We run three different WinZip benchmarks: CPU, EZ (maximum compression), and OpenCL-accelerated. In all cases, the outcome is similar. A stock Core i7-4790K narrowly outperforms our retail Core i7-4770K with a moderate overclock applied. In turn, the tweaked 4790K enjoys slightly quicker completion times.

Scaling in WinRAR isn't particularly impressive. You get less than a 10 percent improvement going from the stock Core i7-4770K to the overclocked Core i7-4790K.

7-Zip isn't much better: the delta rises to just over 10 percent. The good news is that you get 9 percent more speed going from stock 4770K to stock 4790K, all for the same price.

9. Results: Power Consumption

The following chart reflects power consumption throughout our benchmark suite, which gets logged every two seconds. The long, straight section at the end represents 30 minutes of idle time inserted by our automated script to better reflect actual use when we calculate averages.

It's pretty clear that going from Core i7-4770K to -4790K increases power consumption under load. That much we expected. More strange is that the stock Core i7-4790K doesn't settle into the same idle state as the stock -4770K (or even the overclocked -4790K, which does drop down around 50 W). It's possible that MSI's Z97 Gaming 7 motherboard isn't properly dropping into the right C-state by default, correcting the behavior only when we overclock manually. We'll take this into account as we present the next chart, though.

The other observation we make is that consumption rises noticeably once we apply more voltage and a higher clock rate to the Core i7-4790K. No surprise there. Let's have a look at how average use is affected.

The above chart includes a couple-thousand data points averaged together for each CPU. I specifically factored out the idle time, though, due to the obvious anomaly suffered by the stock Core i7-4790K. We'll keep things fair and stop short of running efficiency numbers. But when these CPUs are churning through our scripted benchmark sequences (all of the applications presented on the preceding pages), you can see how big of a difference there is between them. Overclocking takes the Core i7-4790K up an extra 20 W, on average. And that's on top of a 15 W increase going from stock Core i7-4770K to -4790K.

Of course, these are still systems with 16 GB of DDR3 memory and a GK110-powered GeForce GTX Titan. Power consumption is hardly what we'd call egregious.

10. Core i7-4790K Adds Enthusiast Appeal To Haswell

You might call the Core i7-4790K Haswell’s Super Saiyan form. Intel didn’t rework its thermal interface material or power delivery because the Core i7-4770K was facing pressure from AMD. No. Devil’s Canyon appears as the company’s response to guys like me who’ve poked at it for multiple generations about a lack of attention shown to enthusiasts.

What we get in return is a CPU operating 500 MHz faster, designed to complement the just-released 9-series platform controller hubs, and best of all, available at the same ~$340 price point as Core i7-4770K. Intel didn’t need to pile on all of that frequency. It could have prevented partners from extending 8-series chipset compatibility. And the company would certainly be within its right to bump prices up. But it’s being more benevolent than the jaded critics might have expected.

Instead, Core i7-4790K surfaces as the Haswell-based flagship we should have had a little more than a year ago. Where our reception of the 4770K was tepid at best, Intel’s 4790K at least satisfies our desire for demonstrable performance improvement. The processor doesn't overclock worlds better than the 4770K, but additional headroom is never guaranteed. It's the extra 500 MHz promised from the same die you're going to want. With that said, if you ignored my original indifference and bought Haswell when it was introduced, 4790K isn't going to compel another upgrade. But if you’re coming from something in the Sandy Bridge generation, or even certain Ivy Bridge-based CPUs, it's going to be a lot more interesting than 4770K was.

Then again, if you’re on a budget, and spending $340 on a host processor isn’t viable, there are two other unlocked options from Intel sure to enjoy mainstream success. The Core i5-4690K operates at a 3.5 GHz base clock rate and 3.9 GHz top Turbo Boost setting, while the Pentium G3258 offers a 3.2 GHz frequency. We’ve tested K-series i5s before, and know they are some of the most effective gaming processors available thanks to efficient architectures and overclocking headroom. That 20th anniversary Pentium is something completely new, though. Will its dual-core configuration overclock well enough to outpace AMD’s Athlon X4 750K in general desktop and gaming tests? You can bet we’ll be answering that question soon enough.

One last parting shot: I know there aren't a ton of comparison numbers in today's charts. I really wanted the face-off to be between Core i7-4790K and -4770K using our latest benchmark versions. But paging back through some of the tests that haven't changed in Intel Core i7-4960X Review: Ivy Bridge-E, Benchmarked, it's worth noting that Core i7-4790K, even overclocked, trades blows with the Core i7-3930K at its stock clock rate in most threaded benchmarks (Haswell obviously smokes Sandy Bridge-E in tests that run on one core). I know that was a $600-something processor two-and-a-half years ago, but it sure holds up well. You have to be happy as an enthusiast if you're still sitting on a tuned -3930K.