2nd Gen Threadripper 2990WX: AMD’S 32-core CPU is insanely fast but not for everyone
AMD’S Ryzen Threadripper 2990WX crushes multi-threaded tasks like we’ve never seen before.
Stop, AMD. You had us at 32-core, 64-thread Ryzen Threadripper 2990WX consumer CPU. You didn’t have to make it better by saying this weapon of thread destruction could be ours for $1,799 (available on Newegg [ go.pcworld.com/ egrz] or Amazon [ go.pcworld.com/amrz] ) —just $76 more than what Intel wanted us to pony up for its 10-core Core i7-6950x two
years ago. In Millennialese: That. Is. Just. Insane.
But before you invest too much thought or cash into the concept of a 32-core CPU sitting in your PC at home, there’s a lot of caveats you need to know. Simply put: This CPU may be too much power for most of us.
WHAT IS RYZEN THREADRIPPER 2990WX?
If you’re wondering just how AMD went from an 8-core Ryzen 7 1800X to a 16-core Ryzen Threadripper 1950X to a 32-core Ryzen Threadripper 2990WX in the space of 16 months, while it took Intel three years just to go from a 6-core Core i7 to a 10-core Core i7, the magic is in the design.
What makes a 32-core Theadripper even possible is the multi-chip design. Rather than the single contiguous or monolithic die approach that Intel takes, AMD CPUS are multiple chips joined together by the company’s high-speed Infinity Fabric. The original 16-core Ryzen Threadripper 1950X joined two 8-core chips together.
With the 32-core Ryzen Threadripper 2990WX AMD joins four 8-core chips together.
This method comes with its own special penalty, though. Although the STR4 socket for Threadripper is physically the same as the server socket used for AMD’S Epyc CPUS,
STR4 is wired to support four-channel memory using two of the dies, rather than eightchannel memory using four dies.
On Threadripper, that essentially means that of the four dies in the 2990WX, two are
pure compute-only dies, without direct access to memory and to PCIE. Those two compute dies must talk through an I/O die that has PCIE and access to the memory. This design means an I/O die with memory access has 64ns of latency to memory, while a compute-only die has a latency of 105ns.
There’s also a reduction in bandwidth across the Infinity Fabric. On the new 16-core Ryzen Threadripper 2950X, which uses just two dies, the bi-directional die-to-die bandwidth is 50Gbps. On the four chip, 32-core 2990WX, the bi-directional die-to-die bandwidth is halved to 25Gbps.
For what it’s worth, that die-to-die bandwidth is apparently considerably less ( go. pcworld.com/frls) than a 7000-series server Epyc CPU’S 42Gbps. What impact that lowered die-to-die bandwidth has on performance isn’t clear to us, nor is the reason for less bandwidth. It’s possibly due to how the CPUS are connected to the motherboards themselves. The serverfocused Epyc CPUS feature 8-channel memory, with each die accessing its own set of RAM, instead of Threadripper’s shared approach.]
THE RYZEN EFFECT
What that multi-chip design does do is enable core-count scaling at a rate unseen before. With Intel’s monolithic design, an 18-core
CPU would require that every single die be nearly perfect and all of the cores functional to be sold. With Threadripper, to get to 32 cores, it just needs four functional 8-core dies. This all adds up to the crazy number of cores now available to consumers.
AMD has called this the “Ryzen Effect,” and you can see this on the chart below, where we mapped out Intel’s major CPU launches over the years and how many cores they’ve had. So what caused that spike in core counts in the last year and a half? It took Intel from 2008 to 2016 to go from 6 cores to 10 cores. It’s taken AMD 18 months to from 8 cores to 32 cores.
DON’T WORRY, IT’S COMPATIBLE (MOSTLY)
With the 2nd gen Threadripper, there was much hand-wringing that the CPUS might not
work with the existing X399 motherboards. AMD has said every single X399 board available today will work once you’ve updated the UEFI/BIOS to support the newer chip. All of the X399 motherboards support “BIOS Back” features, which let you update a board’s BIOS via USB without requiring an older CPU.
While all of today’s motherboards will work, they might not all overclock the same— but even there the news is mostly good. AMD said the main issue is the massive power draw of the 32-core and 24-core versions of the chip, so some board vendors have beefed up existing boards by offering cooling kits.
32-CORE THREADRIPPER 2990WX PERFORMANCE
For this review, we spooled up the Ryzen Threadripper 2990WX in an MSI MEG X399 Creation motherboard with Windows 10 Fall Creators Update and 32GB of DDR3/2933 RAM. For graphics we run a Founders Edition Geforce GTX 1080 and the latest Nvidia graphics drivers available. Storage is a Kingston Hyperx Savage SSD. Both systems
were cooled with closed-loop coolers. The Core i9 used a Corsair 280mm H110i, and the Threadripper 2990WX used an Enermax Liqtech 240 TR4 cooler with cold plate that offered full coverage for the giant Threadripper. Both coolers were set to maximum fan speed.
For fairness, rather than recycle older numbers, we updated the original 18-core Core I9-7980XE setup that we used in that CPU’S review ( go.pcworld.com/i9rv) with the same version of Windows, newer Nvidia drivers, and the newest BIOS. The last detail is key, as it’s been some time since the original Core i9 review, and we were curious as to whether its performance had improved with a newer BIOS.
The last time we compared Ryzen Threadripper vs. Core i9 ( go. pcworld.com/ rti9), Intel’s 18-core Core I9-7980XE took home the prize for performance (although not for value). This is the one to beat.
For context, we’ve included scores for some CPUS that were run on a previous build of Windows. The numbers haven’t shifted, so they’re still valid. We’ll note where you might want to dismiss results for older chips, or we’ll simply exclude them if we think they don’t apply.
CINEBENCH PERFORMANCE
Up first is Maxon’s Cinebench R15. This multi-threaded benchmark is based on the engine used in the company’s professional Cinema4d product. The engine is somewhat older, but superbly efficient. It scales well with core and thread count as well as clock speed.
The result speaks for itself, as Threadripper 2990WX dusts the rest of the pack. The 32-core Threadripper 2990WX is 52 percent faster than the previous champ, the Core
I9-7980XE.
If only it were as easy as running Cinebench and declaring a winner. Reality is a lot more nuanced, though, so we also run Cinebench with it set to use just one thread. This favors CPUS with higher instructions per clock, and also ones that can hit higher clocks.
The winner is the 8th-gen Coffee Lake-s Core i7-8700k, thanks to its high Turbo Boost clock scores. Intel’s 18-core Core I9-7980XE comes in second, with other Skylake-x and Kaby Lake CPUS following. We don’t see AMD show up until we see the Ryzen 7 2700X in 7th place. Granted, the
scores are fairly close, but those higher Turbo Boost scores clearly put Intel in the driver’s seat.
BLENDER PERFORMANCE
Our next test is the opensource Blender 3D modeling and rendering application, which has seen some use in indie movies.
It’s so popular, even NASA now distributes its 3D model for Blender.
The CPU rendering option favors more cores, and the performance of the
Threadripper 2990WX again is a crazy 37 percent faster than the 18-core Core i9 chip.
For this test, both the Core i9 and Threadripper 2990WX were on the latest 2.78C version, but we also included the performance CPUS runs using 2.78B for reference on older CPUS.
CORONA PHOTOREALISTIC RENDER PERFORMANCE
Up next is the Corona Photorealistic Renderer. Available for 3ds Max and Cinebench, the renderer is seeing popularity in architectural design and visualization. As with other 3D rendering tasks, Corona loves CPU threads, ergo the 32-core Threadripper takes the top spot.
The performance of the 32-core 2990WX, is about double that of the 16-core Threadripper 1950X. The 18-core Core i9 does rather well, though, so it’s entirely the upcoming 28-core Intel part will take this one away from AMD when released later this year.
V-RAY RENDERER
V-ray is an advanced 3D renderer that’s notched some good wins in its belt, as it was used for some effects scenes in Doctor Strange, Captain America: Civil War, and Deadpool. The benchmark can be used to measure both CPU and GPU performance,
but we’re looking only at the former.
Like most renderers, V-ray just loves CPU cores, making the new 32-core Threadripper 2990WX the clear winner. That’s just smoking. For comparison, PC maker Puget Systems measured a dual 14-core Xeon E5-2690 V4 system with a score of 31. So yes, that’s a $1,800 consumer CPU eating the lunch of $4,200 worth of Xeons.
POV-RAY PERFORMANCE
Our last rendering test is POV-RAY—A ray tracing program that dates back to the Commodore Amiga in the 1980s. It’s obviously been updated along the way, and like everything you’ve seen before, thread count should count the most. No surprise, we see the 32-core 2990WX eat everone’s lunch yet again. That 18-core Core i9 is in distant second place.
POV-RAY also allows single-threaded