Last month, AMD’s Ryzen Threadripper 1950X slipped past Intel to claim the overall high-end performance crown for the first time in over a decade. Threadripper’s workstation-class benchmark performance has been excellent since AMD’s new CPU core debuted back in March, and Threadripper gave the smaller company a big-iron desktop CPU that could beat Intel at its own game and look good doing it. (We’ll leave the once-oxymoronic concept of a “big-iron desktop” CPU for another day).
Intel’s initial response to Ryzen and Threadripper was to adjust the features on several SKUs, discuss plans to bring six-core chips to desktops, and to slowly roll out higher core counts on its Core X-Series of CPUs. The Core i9-7900X launched in early June, with 12-core and 14-core CPUs dropping as the summer progressed. Today, Intel is launching Core i9-7960X and 7980XE Extreme Edition. AT $2,000 and $1,700 these chips aren’t cheap, but the 18-core Core i9-7980XE also offers the highest level of performance you can buy today.
We’ve previously discussed Intel’s new Skylake-SP architecture, but to recap: Prior to the new Core-X Series, Intel’s high-end desktop processors (HEDT) used a relatively small (256KB per core) L2 and a large shared L3 that allocated an average of 2.5MB per CPU core. Skylake-SP keeps the individual L2 and shared L3, but changes the ratios. Skylake-SP processors have 1MB of L2 per CPU core, but shrink the L3 back to 1.375MB per core. This has generally worked out as a positive — while the older Broadwell-E designs still win some tests, Skylake-SP has proven itself to be a superior replacement on the whole.
Intel’s Core-X Product Stack
Intel’s Core-X product stack, from most to least expensive, is shown below:
At or below the Core i9-7940X, Intel charges $100 per core. The 16-core i9-7960X is $1,700 ($106.25 per core), while the 18-core Core i9-7980XE is $111 per core. That obviously puts Santa Clara on the defensive as far as price/performance is concerned, given AMD offers a 16-core Threadripper for $1,000 ($62.50 per core). Back when Piledriver was AMD’s best architecture, Intel could sell one core for every two of AMD’s and still expect to come out comfortably on top. That’s not the case anymore. The major comparison here will be between the Core i9-7980XE and AMD’s Threadripper 1950X. Intel has an edge in top clock speed and in total core count, but it’s also asking double Threadripper’s price.
We’ve previously covered the Core i9-7900X, the X299 platform, and Threadripper itself, so we’re going to dive straight into test results here.
The Brand-New Chip Blues
One thing we want to note up-front is we had a great deal of trouble making the Core i9-7980XE behave according to its stated turbo frequencies and default behavior. Turbo Boost is supposed to increase the CPU’s clock speed when the chip is only running a few threads, to speed up overall performance. Our chip literally did the opposite, as shown below:
We typically test in Windows 10’s “Balanced” CPU profile, but that proved untenable here. The CPU clock can dip substantially when lightly loaded in that mode, at least when paired with our Asus X299 Prime-A motherboard. Setting the CPU to “High Performance” improved, but did not resolve, this situation. The CPU clock stopped dropping below 2GHz in the middle of single-or-lightly-threaded tests, but it refused to burst up to its specified maximum frequency of 4.2GHz. We’d like to thank both Rian Lawson of Intel and Gary Key of Asus for their extensive assistance — on a Sunday no less — with troubleshooting these problems, but despite hours of testing on this specific issue, we were unable to find the UEFI options that would implement the behavior Intel told us to expect. We worked around the issue by manually setting Turbo frequencies depending on how many cores a given benchmark would stress, but this obviously isn’t how Turbo Boost is supposed to work.
These types of issues are not uncommon with early CPUs, but they can throw off power consumption figures and CPU down-throttling from default. We’ve limited ourselves to performance comparisons as opposed to power consumption. Unfortunately, we were unable to test the 16-core Core i9-7960X due to the time we spent testing the Core i9-7980XE’s odd behavior.
Test Configuration, Results
Our Intel and AMD were benchmarked with 32GB of DDR4-3200 and a GTX 1080 Ti running Nvidia’s 384.94 driver. Windows 10 Creators Update was installed on all testbeds. The Intel Core i9-7900X and i9-7980XE both used an Asus X299 Prime-A motherboard, while AMD’s Threadripper 1950X used the Asus ROG Zenith Extreme.
Our benchmark results are shown in the slideshow below. Each slide can be clicked on to open it in a new window.
The Highest-Performing (and Most Expensive) Desktop CPU You Can Buy
The Core i9-7980XE occupies an odd position. It’s the fastest “desktop” CPU you can buy today and it combines Intel’s strong single-core performance with the huge thread counts that were recently the sole province of AMD in this market. Compared strictly with Intel’s own HEDT processors, it’s a much better value than any HEDT chip Intel has ever launched, right back to Intel’s first Westmere six-core CPUs. The Core i7-6950X (Broadwell-E) debuted on May 31 2016 and cost ~$1,799 for a 10-core chip. Most of Intel’s relevant customers likely didn’t pay anywhere near that much for the CPU, but the list price was still $180 per core. The Core i7-5960X (Haswell) was $1,000 for eight cores, or $125 per core. Intel, therefore, can spin this as an improvement on its own per-core pricing — and it is.
The problem for Intel’s triumphant narrative is, well, AMD. The Core i9-7980XE is unquestionably fast, but it’s not 2x faster, or even 50 percent faster than Threadripper in any test we ran. CPUs above $1,000 are going to be less elastic than the conventional desktop market, but cost always matters to some extent. Just because companies or individuals can afford to pay top dollar for a CPU doesn’t mean they don’t care about price at all. When Intel had the high-end market entirely to itself, the company could afford to set its own prices. With AMD’s Threadripper 1950X already in market, it’s harder to justify the cost.
Customers who want the absolute highest-end CPU and can afford to pay for it will prefer the Core i9-7980XE. But anyone who doesn’t fit into that market is going to be hard-pressed to opt for the Core i9-7900X when the Threadripper 1950X offers higher workstation performance at the same price. Intel has retaken the performance crown, but it hasn’t swept the workstation field — not by a long shot.