Introduction, Chip Background CPU Testing
If you’re in the market for a new desktop CPU, you’re definitely not suffering for choice here in 2017.
We started off the year with the launch of Intel’s 7th Generation “Kaby Lake” Core i7-7700KRyzen 7 1800XCore X-Series on the Intel side, and AMD’s competing Ryzen Threadripper chips on Team Red’s side of the test bench.
So much has been going on in the realm of CPUs this year that it’s really beyond the scope of this review. You can get a decent sense of where we’re at from checking the recent reviews of the Intel Core i9-7900XAMD Ryzen Threadripper 1920Xour Components page, click the “Reviews” button in the top navigation bar, and skim through the 16 processors we’ve tested and reviewed so far this year. (Go ahead. We’ll wait.)
Welcome back! Now that you’re all caught up, we’re sure you’re at least as enthusiastic as we are to look at the Intel Core i7-7820X and see where it fits in.
Intel Core i5-7640X, right up to the (still not officially launched) 18-core Intel Core i9-7980XE. The model we’re looking at here has a 3.6GHz base clock and the ability for two cores to ramp as high as 4.5GHz using Intel’s Turbo Boost Max 3.0 feature. The Boost speed is significant, as it’s a higher stock clock speed than any other Core X-Series chip, save for the Core i7-7900X, one step up the stack, which can also hit 4.5GHz.
Currently, nine chips make up the Core X-Series lineup, spanning across two architecture generations: 6th Generation Core (dubbed “Skylake X” in their iterations here) and 7th Generation Core (“Kaby Lake X”). Rather than rattle off the full list of chips and their basic specs, here’s a chart, direct from Intel…
The two 112-watt chips on the bottom are based on Kaby Lake architecture, while everything above the Core i7-7740X is based on the older Skylake silicon. In some ways, that’s not a huge deal, since the two generations are very similar. The primary difference is that the newer Kaby Lake chips have hardware that makes them compatible with protected video-stream content in 4K/HDR for current and upcoming services from the likes of Netflix, Amazon, and others. The lesser Kaby Lake X chips also use dual-channel DDR4 memory, while the Skylake X parts support quad-channel setups.
For the record (and in case you didn’t go read one of the previous Core X-Series reviews for more context, tsk tsk), all of these chips use the same LGA 2066 socket, and are compatible solely with the X299 chipset. We aren’t going to detail the chipset, memory, and other considerations here, but instead point you to earlier reviews, notably the 10-core Intel Core i9-7900X, for that.
The big differentiator between these chips, aside from the numbers of cores and threads, is the number of PCI Express lanes connected to the chip, which is important for installing bandwidth-hungry components such as graphics cards and PCI Express/NVMe solid-state drives (SSDs). The pair of four-core chips in the Core X-Series lineup (the two Kaby Lake X chips at the bottom of the chart above) have just 16 lanes, which is the same as what you’ll find on mainstream offerings like the Core i7-7700K. The five Core i9 Skylake X chips that have 10 or more cores have 44 PCI Express lanes, while the Core X “middle chips” (including the Core i7-7820X we’re looking at here, and the lesser Core i7-7800X) have 28 lanes available from the CPU.
Now, for most users, 28 lanes should more than suffice, including gamers and enthusiasts who may want to install a couple of high-end graphics cards in an SLI or CrossFireX configuration, plus perhaps a pair of fast PCI Express-based SSDs. Keep in mind, though, that the X299 chipset provides up to 24 lanes of its own for storage, USB ports, and other bandwidth-hungry features. AMD’s competing Ryzen Threadripper platform, however, delivers 64 lanes of PCIe on all of its processors, including the recently announced, lower-end ($549) Threadripper 1900X eight-core.
We’re honestly not sure how all but the most extreme (and the wealthiest) of users could actually make use of all those lanes. But if you have your reasons, you may want to go the AMD route. Just know that Threadripper motherboards (which run on the new X399 chipset) are undeniably expensive, starting at $340 when we wrote this. Comparable Core X-Series motherboards (running the X299 chipset) start at a comparatively “inexpensive” $210.
Really, though, if a bargain is what you’re after, and you don’t need more than eight cores and 20 available PCI Express lanes from the CPU, the Ryzen 7 1800X is going to be tough to beat. That chip sells for about $429 (and we’ve seen it as low as $399 via some in-store retail specials), with decent, compatible B350 motherboards including an M.2 connector for speedy storage and some LED bling, selling for as little as $69 when we wrote this.
In contrast, the also-eight-core Core i7-7820X we’re looking at here sells for about $599. (BH had it on sale for $586 when we were wrapping up this review.) Paired with an entry-level X299 motherboard, you’re looking at about $800 for a chip-plus-motherboard for the eight-core Intel option, versus as little as $500 for the eight-core AMD option.
As we’re about to see in testing, the Intel Core i7-7820X performs better than the AMD Ryzen 7 1800X overall. But does it perform enough better to warrant as much as a 60 percent increase in cost for the board and processor combined? And how does Ryzen Threadripper and the 12-core, $799 Threadripper 1920X stack up against these two options? For that, we’ll have to delve into testing and take a close look at performance. So let’s do just that.
CPU-Specific Performance Testing
For our test setup, we dropped the Core i7-7820X into the Asus Prime X299-Deluxe motherboard of our Core X-Series testbed PC, along with 32GB of Corsair memory running in a quad-channel setup. An Nvidia GeForce GTX 1080 Founders EditionKingston HyperX Savage was our SATA-interface boot drive. We stuck all those components into Deepcool’s GamerStorm Genome ROG Certified case, which includes a self-contained liquid cooler with a large three-fan radiator.
The Core i7-7820X sits between mainstream chips such as the four-core Core i7-7700KRyzen 7 1800XAMD Ryzen Threadripper 1920X and the 10-core Intel Core i9-7900XAMD Ryzen Threadripper 1950XIntel Core i7-6950X Extreme EditionIntel Core i7-6900K. The last two were known as “Broadwell X” in their day.
Also, those last two chips should show how far we’ve come from a price-to-performance standpoint in the last year or so—at least when it comes to tasks that like lots of cores and threads. But we suspect the Core i7-7820X’s chief competition will come from AMD’s Ryzen 7 1800X, which was selling for as low as $429 when we wrote this. The Threadripper 1920X will likely outclass the Core i7-7820X, thanks to its 12 cores. But it also sells for for $799, or a little less. And AMD’s Threadripper motherboards are more expensive than many comparable Intel X299 options, so that makes the Threadripper chip in effect more expensive to deploy.
First up in our testing regimen: Maxon’s CPU-crunching Cinebench R15 test, which is fully threaded to make use of all available processor cores and threads, using the CPU rather than the GPU to render a complex image. The result is a proprietary score indicating a PC’s suitability for processor-intensive workloads.
Along with the usual test that makes use of all available cores, we’ve added the single-core results here to get a sense of how Intel’s eight-core chip fares in lightly threaded workloads.
As we expected, the Core i7-7820X did better here than the Ryzen 7 1800X, but the gulf between the two isn’t as great as you might expect given the $170 price difference between the two CPUs alone. Keep in mind, again, that you can pick up B350 motherboards (with lighting and an M.2 connector) as low as $70, or about a third the price you’ll pay for an entry-level X299-based board for the Intel chip. That said, the Intel Core i7-7820X is a faster performer, pulling 19 percent ahead of the 1800X on the single-core test here, and about 8 percent ahead in the multi-core test.
The Threadripper 1920X did almost 40 percent better than the Core i7-7820X on the multi-core test, but it’s also a more expensive processor that runs on a pricier platform.
iTunes 10.6 Conversion Test
We then switched over to our venerable iTunes Encoding Test, using version 10.6 of iTunes. This test taxes only a single CPU core, as much legacy software still does.
Music encoding doesn’t exactly push a modern CPU to its limits, and certainly not ones like these. But this is precisely the kind of test that shows Intel’s chips to their best advantage. Intel’s recent Skylake and Kaby Lake architectures do better than AMD’s Zen on single-thread or lightly threaded tasks. That said, unless you’re hanging on to some very old programs, most software that can take good advantage of multiple cores and threads has been updated to do so at this point.
The Core i7-7820X managed to do better here than any other consumer chip we’ve tested, if only by a second or two. The much less expensive Intel Core i7-7740X (not charted here) finished this same test just a second behind the Core i7-7820X. So while the Core i7-7820X excels at lightly threaded workloads, particularly against AMD’s offerings, it doesn’t really offer a new level of performance. The Core i7-7700K, which debuted in January 2017, also performs about as well on this front, for a lot less.
This is a time-consuming test of video-crunching capabilities. Handbrake, a tool commonly used for converting videos from one format to another, benefits from having lots of cores and threads at your disposal. In this test, we use a nice, big hunk of 4K video to see how the chips perform with a sustained task of this kind. We tasked the CPUs to convert a 12-minute-and-14-second 4K .MOV file (the 4K showcase short film Tears of Steel) into a 1080p MPEG-4 video.
On this first real-world test that takes advantage of lots of cores and threads, we again see the Ryzen Threadripper 1920X and 1950X in another league, as we’d expect. And the Ryzen 7 1800X was indeed slower than the Core i7-7820X, but not substantially so. The eight-core AMD part finished this test 25 seconds behind the Core i7-7820X.
Next up, using the “All CPUs” setting, we ran the POV-Ray benchmark, which challenges all available cores to render a complex photo-realistic image using ray tracing. After that, again to get a sense of how the Core i9 handles single-core performance, we ran the same benchmark using the “One CPU” setting.
Once again here, the Core i7-7820X was a few seconds ahead of the Ryzen 7 1800X on the multi-core test, and more than two minutes ahead on the longer-running single-core test. The Ryzen Threadripper 1920X was similarly behind on the single-core test, but significantly faster than the Core i7-7820X when all cores and threads were engaged. Given that the Ryzen Threadripper chip has four more physical cores, we’d expect that.
Blender is an open-source 3D content-creation program that can be used to design and create visual effects, animation, and 3D models for use in video games or 3D printing. We open a standard test file (it’s of a flying squirrel) and time how long the test processor takes to finish the render.
The results here were all fairly close, with the Core i7-7820X pulling even with the pricier Core i9-7900X chip for the lead. Interestingly, the Ryzen Threadripper 1920X was just a second behind these two, but the Ryzen 7 1800X landed at the back of the pack, 5 seconds behind its closest competitors.
7-Zip File Compression
Last, we fired up the popular 7-Zip file-compression software and ran its built-in compression/decompression benchmark, which is another useful test of a CPU’s multi-core abilities.
This last test showed the eight-core Core i7-7820X in its best light (at least on a core-hungry benchmark), where it eclipsed the Ryzen 7 1800X by more than 20 percent. If you’re often compressing/decompressing large file sets, that certainly gives the Core i7-7820X an advantage. Then again, if such tasks are that important to your workflow, the Ryzen Threadripper and its 12 cores outpaced the 7820X by about 24 percent. Again, the Threadripper is a costlier chip on a pricier platform. So you’ll want to tailor your budget and platform choices to your needs and your particular workflow.