Cores and clock speeds, base, boosts, and threads: the march of progress in the processing world continues ever on. With each passing generation, we see these advancements tick by but with Coffee Lake, Intel is defending their claim on the marketplace superiority against a reinvigorated AMD. We wanted to see for ourselves just what Intel’s latest i7 has to offer, so today we’re putting the Intel Core i7-8700K through its paces. We’re upgrading from an i7-7700K and had to know: is it worth the upgrade?
- MSRP: $359-379
- # of Cores: 6
- # of Threads: 12
- Processor Base Frequency: 3.70 GHz
- Max Turbo Frequency: 4.70 GHz
- Cache: 12 MB
- Bus Speed: 8 GT/s DMI3
- TDP: 95 W
- Max Memory Size (dependent on memory type): 64 GB
- Memory Types: DDR4-2666
- Max # of Memory Channels: 2
- Processor Graphics: Intel® UHD Graphics 630
- Graphics Base Frequency: 350 MHz
- Graphics Max Dynamic Frequency: 1.20 GHz
- Graphics Video Max Memory: 64 GB
- # of Displays Supported: 3
- Intel® Optane™ Memory Supported: Yes
- Intel® Turbo Boost Technology: 2.0
- Intel® vPro™ Technology: Yes
- Intel® Hyper-Threading Technology: Yes
- Intel® Virtualization Technology (VT-x): Yes
What Does It Have To Offer?
If you’re a gamer, the i7-8700K is the the best processor money can buy. Where last generation’s i7-7700K suffered scrutiny for a lack of meaningful upgrades outside of frequency, today’s Coffee Lake takes things up a notch by offering and two processing cores, up from last generations four. Thanks to hyperthreading, the 8700K has an unlocked 6 core/12 threads of performance. On top of that, the base clock of 3.7GHz will boost to an impressive 4.7GHz out of the box. With little effort, we were able to lock our processor to a stable 5GHz, which has a noticeable impact in games - particularly the new Kingdom Come: Deliverance.
Note: If overclocking isn’t your thing, be sure to check out the i7-8700. The “K” in Intel CPUs refers to whether or not it’s able to be overclocked.
Those additional cores make a big difference in tasks that will take advantage of it. I’ve been producing more videos than ever for our YouTube channel and the combination of faster clock speeds and more cores definitely makes rendering and navigation in Adobe Premiere and After Effects faster. If you’re a single-system streamer, you’ll also benefit as your system has an easier time keeping up gaming and broadcasting at the same time.
The increase in core count has been applied down the chain, too. If you’re a gamer who doesn’t use creative apps or stream often, Intel’s Core i5-8600K would be a good option. It doesn’t feature hyperthreading (that’s i7 only), but rocks a full 6-core count like its bigger i7 brother. Further down into the i3 line, Intel has bumped both the i3-8350K and i3-8100 to full quad-core status, up from 2C/4T last generation.
For gaming, those extra cores aren’t going to offer an amazing improvement to your framerate if you’re already on a four-core system - at least right now. So far, developers are still holding tight to the quad-core design target, but slowly but surely, games are releasing that do take advantage of that extra performance. On a personal level, when I’m building a new system, I feel better knowing it’s ready to take advantage of whatever may come. Future proofing may be a pipe dream in the PC world but it feels good to plan ahead.
Specs-wise, many of the internals are the similar to Kaby Lake, but there are a couple of exceptions. We see a 4MB increase in L2 cache, which is expected, but also a boost to 95W TDP. This is a bump from the already warm 7700K’s whose TDP was 91W. This makes heat more of a concern, especially when overclocking and putting the system under load. We’ll get into temperatures after our framerate tests, but this does result in a hotter chip. If you plan on overclocking, we recommend a quality cooler.
Like Kaby Lake and Skylake before it, all Coffee Lake chips maintain 16 PCI-E lanes, with an additional 24 provided by the chipset. This is enough to cover the majority of mainstream applications, including two GPUs and an NVME SSD.
The i7-8700K also comes with a built-in iGPU with the Intel UHD 630. If you’re reading this, you probably have a dedicated GPU but if not, the UHD 630 will more than suffice for web browsing and even some eSports gaming. It’s the same iGPU that shipped with the Core i7-7700K and our friends at PC Gamer have a good rundown of its surprisingly respectable performance.
Test system 1: Intel Core i7-8700K at 3.7GHz, ASUS Maximus X Hero motherboard, Nvidia GTX 1080 Ti Founder’s Edition, 32GB Ballistix Elite DDR4-3200 DRAM, Samsung 960 EVO system drive, 10TB Western Digital Gold mass storage, Corsair HX-1050 1050-watt PSU, Noctua NH-D14 dual fan CPU cooler, Nanoxia DS-1 case.
Test system 2: Intel Core i7-7700K at 4.2GHz, MSI Gaming M7 motherboard, Nvidia GTX 1080 Ti Founder’s Edition, 32GB Ballistix Elite DDR4-3200 DRAM, Samsung 960 EVO system drive, 10TB Western Digital Gold mass storage, Corsair HX-1050 1050-watt PSU, Noctua NH-D14 dual fan CPU cooler, Nanoxia DS-1 case.
With that, it’s time to get into the tests. We tested the 8700K against last generation’s i7-7700K as well as the AMD R7 1700X from our AMD benchmarking system. Test data was gathered first on the 7700K system which was then rebuilt with the Maximus X Hero and our i7-8700K. Our AMD tests were conducted last, swapping core components into the system for consistency.
The R7 1700X features 8 cores and 16 threads but a slightly lower clock speed. Unfortunately, our unit wasn’t a good overclocker and couldn’t hit the higher frequencies of the 1800X (which is the differentiating factor between the 1700X and 1800X SKUs). As such, we present the data from a stock 1700X.
Starting with synthetics, we began with 7-ZIP in both single- and multi-thread compression tests. Single-threaded tests put an emphasis on frequency whereas multi-threaded tests benefit from additional cores.
The 8700K clearly leads the pack in both tests. I was rather surprised to see the lead it earned over the 1700X which has an additional two cores to its advantage.
Next, we turned to Cinebench to assess the rendering capabilities of each processor. In the single-thread benchmark, both i7s have the edge on our 1700X. When we run the multi-threaded test, the tables turn with the 7700K falling expectedly behind and the 1700X just eeking out our 8700K. It should be noted that when overclocked to 5GHz, the 8700K reported a score of 1620, far surpassing the results above.
With Cinebench and 7-Zip out of the way, it was time to look at gaming benchmarks. We started with 3DMark’s Fire Strike test at the three major resolutions: 1080p, 1440p, and 4K. At 1080p, the 8700K is the clear winner, pulling ahead of both the 7700K and vastly ahead of the 1700X. When we begin to raise the resolution, though, the heavy lifting shifts over to our GPU and we see those results level out.
But how about real world performance?
We looked at four games with reliable benchmarking tools at the three resolutions assessed in the Fire Strike benchmark. Here we can really see the kind of dramatic improvement the 8700K offers over something like the 1700X at 1080p and even 1400p. At 1080p, the 8700K maintains an average FPS that is 51-percent higher than AMD. At 1440p, it’s closer but still a spacious 26-percent improvement. At 4K, the bottleneck is clearly on the GPU, bringing the edge to only 5-percent.
Compared against the 7700K, the results are much closer. At 1080p, the 8700K offers offers 14-percent improvement. With the outlier of Hitman removed, that drops to 8-percent or a range of 1-15 frames a second. 1440p offers 5-percent and 4K offers only three.
Overclocking and Temperatures
When it comes to overclocking, I admit to being no expert. That said, I’ve successfully overclocked systems for most of the last decade and know my way around pushing a core clock. As always with overclocking, your mileage will vary depending on the chip you’ve received, but I was quite impressed with how easily I was able to overclock the 8700K.
I began with a target of 5GHz; a nice round number that’s a fairly modest bump over the default boost clock. Since I’m on air cooling with the two-spire, dual-fan Noctua D14, I began by changing my fan profiles to dissipate the extra heat. After changing my multipliers, I set to tweaking my voltages and stress testing. With little difficulty, I was able to achieve a stable 5Ghz with only 1.28V, LLC Level 6. Wanting to see how far I could go, I pushed it a bit further up to 5.1GHz at 1.32V and was able to remain stable after two hours stress testing under Prime95, but temps on both were too far out of my personal comfort level to stay with for day to day use.
Under load at 5GHz overclock, temps peaked at 82C. This is very close to the 7700K which peaked at 81C at 4.8GHz. In normal use, both CPUs hover right between 35-40C and in games between 65-75C. This is a bit alarming at first but shouldn’t be as concerning as if it were the case on pre-Kaby Lake CPUs.
I spent hours researching this issue, concerned that I may have had a faulty heatsink on my 7700K. What I found was that both Kaby Lake and Coffee Lake have higher maximum temperatures; they won’t even throttle below 100C. Intel, for its part, has reassured a number of forum-posting customers who’ve taken the time to call and express their concern load temps in the 80s are nothing to be concerned about. That won’t stop people from delidding or wanting to lower them - I know peaking in the 80s makes me uncomfortable - but you shouldn’t have to worry about doing any damage to the lifespan of your system running under these temperatures.
So is the 8700K a good upgrade? That depends on what you’re upgrading from and what you’ll be using it for. If you’re coming from the Broadwell generation or earlier, like to stream or use creative apps like Adobe Premiere, absolutely. The same is true for really anything from AMD at this point. Compared against our 1700X at 1080p and 1440p resolutions, it’s no contest and we suspect the same of the 1800X. If you’re coming from a 7700k and only play games or host the additional stream, your benefits will be a little more limited. Overall, though, Coffee Lake and the 8700K represent a core improvement and a solid direction for Intel that leaves me excited for the release of Cannon Lake.
- Added cores speed up CPU hungry programs, like Adobe Premiere and After Effects
- Solid built-in GPU for entry-level and eSports gaming
- Rapid out of the box boost speeds
- Easy to overclock (as always, YMMV)
- Temperatures still tend warm
The product discussed in this article was provided by the manufacturer for purposes of review.