AMD Ryzen Threadripper 1920X
A 12-core champion confidently enters the fray
IT’S AN AWESOME TIME to be a PC enthusiast. Just six months ago, there was barely a single AMD CPU worth getting out of bed for. Now, we can hardly keep up with all the crazy new models, each with insane core counts and the promise of ever more preposterous levels of performance.
Enter the AMD Ryzen Threadripper 1920X. We had our dirty paws on AMD’s flagship, the monstrous 16-core 1950X, last issue, so it was time to throw the $800 offering on our bench instead. The 1920X packs a mere 12 cores and 24 threads, but that still makes for an absolute beast of a PC processor. One capable of on-paper feats of parallel processing that simply weren’t available until AMD shook things up with its awesome Ryzen architecture.
As for the specifics, the 1920X clocks in at a 3.5GHz base clock and 4GHz Turbo. Those are very healthy clocks indeed for a chip with so many cores, and that reflects AMD’s clever approach with the Threadripper lineup, which involves a pair of eight-core processor dies in a single package. In other words, given that mainstream eight-core Ryzen CPUs have no problem clocking up to 4GHz, it should be no surprise that Threadripper chips are also capable of a similar figure.
Of course, effectively cramming two CPUs as powerful as Ryzen into a single package has certain ramifications in terms of power consumption, but more on that in a moment. First, it’s worth recalling some of the platform niceties that come with these epic Threadripper chips. Not only do you get quad-channel DDR4 memory support, but also no fewer than 60 PCIe lanes. This is some very serious computing hardware.
That’s something that socks you squarely between the eyes the moment you run some benchmarks. This thing flies. It murders Cinebench in multithreaded mode, with 2,308 points. The single-thread score of 152 is pretty tolerable, too, thanks to that 4GHz top Turbo speed. The raw memory bandwidth is also mega, hitting around 60GB/s for reads and writes. Ouch.
If there is a price to be paid for this raw computational muscle, it’s power consumption. At idle, our 1920X ticks along at a reasonable 67W. Under full CPU, that leaps to 243W. But we don’t have a major issue with that. If you want a lot of performance, you have to pay for the power.
What you might not be so willing to put up with is Threadripper’s mediocre gaming performance. The clever modular architecture AMD has come up with for Zen, complete with its innovative Infinity Fabric interconnect, is hugely effective for many parallelized workloads. But it does create certain latencies, thanks to the way the cores and cache memory are arranged. Those issues are magnified when you have two separate CPU dies in one package, as is the case here.
To offset that architectural shortcoming, AMD has cooked up a special Game Mode for Threadripper CPUs, which does two things. First, it disables one of the CPU dies altogether, leaving you with effectively a conventional single-die Ryzen processor. It also switches the chip’s memory mode to NUMA, which restricts a game’s memory footprint to locally-connected RAM, further reducing latency issues.
The upshot, in theory, is that Threadripper in Game Mode performs on par with a mainstream single-die Ryzen processor of similar configuration. That’s our experience in practice. Run a game such as TotalWar:Attila on the 1920X in the fully-enabled 12-core Creator Mode, and it can be hideously stuttery. In Game Mode, it’s just a little stuttery, like a regular Ryzen CPU. It’s just a pity that you must reboot the system fully to jump between modes.
Not that the patchy gaming performance matters. This 12-core chip is hardly a costeffective way of gaming. For everything else, it’s absolutely killer.