Intel Core i9 review: We test the massive 18-core Core i9-7980X and 16-core Core i9-7960X

Intel strikes back against AMD’s Ryzen Threadripper with its thundrous, core-crammed CPUs.

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We know from our original Core i9-7900X and our Threadripper 1950X review that WinRAR just doesn’t seem to like the mesh-like architectures of the Threadripper and Core i9 chip. No surprise that we’re seeing the same thing here, but it is surprising that Intel’s older Broadwell-E chips orevail. Threadripper just does very poorly here.

core i9 7980x winrar 5.40 nt IDG

RARLab’s WinRAR doesn’t particulary like the new mesh architecture in Skylake-X but it really seems to hate AMD’s Zen architecture.

7-Zip performance

We use the 9.20 version of the free 7-Zip and run the built-in multi-threaded test. The clear winners by a larger-than-expected margin are the new Core i9’s.

core i9 7980x 7 zip IDG

The free and popular 7 Zip puts the chips the most cores at the front of the line. 

Corona Renderer performance

If you look at Cinebench, Blender and POV, the performance spreads between the 16-core Threadripper and new Core i9 is there, though small. In Corona Renderer, we’re seeing performance gaps that might wake you up. The 16-core Core i9-7960X enjoys a 25-percent performance gap over the equivalent 16-core Threadripper 1950X. It’s even worse with the 18-core Core i9-7980X.

Before you scream the benchmark is cooked in favor of Intel’s micro-architecture, this particular benchmark was something introduced to most of us by AMD for the original Threadripper review. Frankly, this just isn’t pretty.

core i9 7980x corona renderer 1.3 IDG

The Corona Render shows the 16-core Threadripper getting hammered by the 16- and 18-core Core i9 chips.

Handbrake performance

Not everyone does 3D modelling for a living, but an awful lot edit or convert videos, and that’s where having more cores generally benefits you. To look at encoding performance of the new Core i9, we used the popular and free Handbrake encoder to convert a 30GB 1080p video using the built-in Android tablet preset.

One issue we’ve seen with the version of Handbrake and the workload we use is the diminishing returns on the big-core CPUs. You can see the we pick up performance as we go from quad-cores to 10 cores, but once we’re beyond 10 cores, we’re not picking up the performance dividends you’d expect at 16 or 18 cores. 

Still, both Core i9s are in front, with Threadripper also giving up very respectable performance here.

core i9 7980x handbrake 1080p encode IDG

Our workload for the free Handbrake encoder favors more cores too but it doesn’t pay the same performance dividends the way a professional 3D renderer would.

Premiere Creative Cloud Performance

The other half of video encoding is obviously in video editing. For this particular test we use Adobe Premiere Creative Cloud 2017 and export an actual project shot by our video department, so it’s as real-world as you can get. The footage was shot on a Sony Alpha camera at 4K resolution and then exported using the Blu-ray preset at 1080p resolution. We also enable the maximum render quality option, which helps improve image quality when changing the resolution. The workload is rendered on the CPU, which some video snobs say still renders the highest-quality video.

Although this is very much a CPU-intensive task, we do try to take the storage subsystem out of the equation so for all but the original Ryzen 5 and Core i5 systems we used Plextor PCIe NVMe SSD as the source and target drive. Like Handbrake, we’re not seeing stellar scaling with core count, but the 18-core Core i9 rules them all.

Still, if you’re buying a big CPU as a video editor, you have to consider whether it’s worth it. 

core i9 7980x premiere cc 4k cpu encode IDG

Video snobs say CPU-based rendering is superior and if you do that—you’ll want more cores.

One thing we also want to add: A lot of people say CPUs are irrelevant in the age of GPU-based encoding. To prove it either way, we switched Adobe Premiere from CPU rendering to CUDA rendering on the GeForce GTX 1080 card. As you can see, you pick up a huge advantage by using the GPU to encode, but it’s clear that having more cores still yields dividends. The upshot is not to think a dual-core CPU will be better than a 10-core CPU for video editing.

core i9 7980x premiere cc 4k gpu encode IDG

Even if you use your GPU for encoding, having a CPU with more cores will still lower your render times.

Rise of Tomb Raider performance

Stop: If you’re buying a 16- or 18-core CPU to primarily play games, you’re doing it wrong. Your funds would be more wisely spent on a faster graphics card. But if you do play games, and you also model 3D, you want to know which CPU gives you the best performance. The answer, as we suspect you know, is Core i9.

We say this because we already know both the 10-core Core i7-6950X and 10-core Core i9-7900X have an advantage in games. The newest Core i9’s don’t change that pattern.

First up is Rise of the Tomb Raider, which has been patched to address some inefficiency on the Ryzen and Threadripper platforms. We run the game at 1920x1080 resolution and the Medium setting in DirectX 11 mode.

In front of the pack is the 18-core Core i9-7980X, but for most part, it’s pretty close to the 10-core Core i9-7900X. Threadripper does decently well once kicked into its Game Mode, but the advantage goes to Core i9.

core i9 7980x rise of the tomb raider 19x10 medium IDG

Intel’s Skylake-X continues to show better performance in most games but Threadripper 1950X is still very much in the ball game.

Tom Clancy’s Rainbow Six Siege performance

We actually ran quite a few games on the CPUs, but for the most part the 18-core Core i9-7980X either led the way or was near the front of the pack. We saw the same trend in Tom Clancy’s Rainbow Six Siege when run at 1920x1080 resolution and Medium settings. We do this to remove the video card from being the bottleneck in performance testing.

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Core i9 takes top honors in Rainbow Six

3DMark Time Spy 1.0 performance

Our last gaming test is 3DMark’s Time Spy 1.0 test. The score is only the CPU portion, because that’s all we care about here. Again, the Core i9-7980X is large and in charge. 

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3DMark’s TimeSpy puts the 18-core on top—but it’s clear the engine doesn’t scale with the core count much.

Power Consumption and clock speeds

One thing that’s come with Core i9-7900X is its power consumption, and how much more power it uses than AMD. That’s typically not an easy thing to test without identical hardware, but as we noted earlier, boutique PC builder Falcon Northwest sent us two nearly identical, heavily loaded Talon PCs. Both feature 128GB of DDR4/2400 RAM, Samsung 960 Pro drives, Titan Xp’s in SLI, and matching power supplies, coolers, and cases. The only differences between them were the 16-core CPUs and motherboards.

This setup let us run the same CPU loads while measuring the power consumed at the socket. Because most workloads don’t actually use all cores, we also decided to look at power consumption while ramping up 1 to 32 threads. The results confirm what everyone knew: Core i9 uses more power. 

core i9 7960x vs threadripper 1950x per thread system power consumption IDG

Using a pair of nearly identical 16-core systems, AMD’s Threadripper 1950X proves to be more power-efficient than Intel’s 16-core Core i9-7960X. 

These power measurements aren’t exact, but they’re close enough to give us an idea. It’s interesting that the Threadripper 1950X seems to level off in power consumption at about 20 threads, while the Core i9 continues to climb.

Threadripper definitely has the advantage in power consumption, but that’s not enough of an edge. If you really care about your multi-threaded performance, an extra dollop of power consumption probably isn’t going to matter to you.

It’s very much like Threadripper’s gaming performance. Core i9 has a definite advantage, but to be honest, it’s probably not going to matter that much given that anyone buying this class of CPU buys for content-creation priorities first.

We’ll close this out with the scaling performance of the 18-core Core i9-7980X under varying workloads.

We did this for our Threadripper review, and we think it’s a great way to understand what you’re getting out of these chips. When it was just the 10-core Core i9-7900X versus the 16-core Threadripper 1950X, the Core i9 had the edge in light loads, but the AMD CPU led in heavier loads.

With these new Core i9’s that’s shifted. Not only does Intel have an edge in light loads—it now has the edge in heavy loads. If you look at our Cinebench R15 results below, you can see the 18-core gives up no quarter to the AMD chip.

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Using CineBench R15, we varied workloads from one thread to 36 to show just where the performance peaks. 

The price: If you have to ask...

The asterisk hanging over Core i9 and the entire Core X series is the value proposition. Ever since our original Core i9-7900X and Threadripper 1950X reviews, we were pretty sure Intel wouldn’t have any issue being the performance leader.

The problem is being the price leader. Trying to peg value per performance can be pretty slippery, because performance is relative. We do know that generally Threadripper is just a little off the pace of Core i9. So we decided to crunch the numbers on cost per thread of all Core X and Threadripper chips. We also threw in the 10-core Core i7-6950X, because, well, $1,723.

bucksperthread IDG

Why isn’t Ben Franklin smiling? He probably paid the full $1,723 for a Core i7-6950X Broadwell-E, which has the highest cost per thread of the CPUs here.

Thread for thread, the worst value is that Broadwell-E chip. Unsurprisingly, Intel’s Core i5-7640X comes in second-worst at $61 per thread. The real shocker here is the best value: AMD’s 32-thread Threadripper 1950X. 

Conclusion

There’s really two ways to look at Core i9. The first is from a performance perspective, where there’s no question that Intel is in charge. You’d have to look very hard and very far to find any multi-threaded benchmarks where the 16-core and 18-core Core i9 lose to AMD’s Threadripper. Once you move to lighter loads that favor Intel’s higher clock speeds and better IPC efficiency, it only gets worse.

So, for performance freaks who absolutely, positively, must have the fastest CPUs for both light duty and heavy duty, the Core i9-7960X and Core i9-7980X are the new speed demons.

The problem, of course, is the cost differential. That last chart above should give you an idea of the value AMD is offering. Yes, Core i9 may officially be faster in every way you can measure, but it can’t outrun its own price. 

Maybe it depends on who’s paying. If, for example, your boss asks you to spec out a new build for your video editing workstation, you’ll say Intel. But if you’re building on your own dime and trying to make the dollars stretch? The natural answer is AMD.

But make no mistake, Core i9 is clearly the performance leader today.

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