AMD Ryzen Threadripper 1920X Review

Introduction

AMD’s Ryzen Threadripper 1950X put a feather in the cap of its high-end desktop aspirations. The company's new line-up challenges Intel's best efforts. But, as usual, some of the best value in AMD's product stack is found in the mid-range models. Ryzen Threadripper 1920X comes arms with 12 physical cores and SMT, enabling 24 concurrent threads fed by 38MB of cache, a quad-channel memory controller, and 64 lanes of PCIe. All of that costs $800, dramatically undercutting the 10-core Core i9-7900X.

Based on the back-and-forth we've witnessed this year, it appears the Ryzen family of CPUs may have caught Intel off-balance. AMD's siren call to enthusiasts includes lower prices, more cores, less segmentation, soldered heat spreaders, less expensive motherboards, and a longer commitment to each platform.

Intel does have pricier Skylake-X options available, but they sag under the weight of deliberate segmentation that fuses off native features on the cheaper models. Don't count Intel out, though; its beefiest Skylake-X chips are still forthcoming, along with a salvo of mainstream Coffee Lake CPUs to rival Ryzen 7, 5, and 3.

AMD has an aggressive roadmap it'll use to improve the Zen architecture and transition to smaller nodes, so the company should remain a competitive force to be reckoned with. Ryzen Threadripper 1920X is a great start, though. Based on the 1950X we already reviewed, this processor is expected to perform well at a reasonable price point (plus the highest overclocking ceiling we’ve seen on a Ryzen processor).

Meet Ryzen Threadripper 1920X

AMD designed its Threadripper processors for anyone able to utilize lots of cores and tons of PCIe connectivity. Think content creators, heavy multi-taskers, and software developers.

The 12C/24T Threadripper 1920X features a 3.5 GHz base clock, which is just 100 MHz higher than the 16C/32T 1950X. Surprisingly, the two chips share the same 3.7 GHz boost frequency for heavily-threaded workloads and a four-core 4 GHz setting for less taxing tasks. If your cooler is robust enough, both processors also enable a four-core 4.2 GHz XFR ceiling.

Like all of AMD's Ryzen processors, the 1920X utilizes two quad-core complexes combined into a single Zeppelin die. Two Zeppelin dies, tied together using the Infinity Fabric interconnect into a multi-chip module, come together to create Threadripper CPUs wielding 16 physical cores. AMD creates the 12-core 1920X by disabling four of them, leaving six cores per die (3+3).

The disabled cores serve as dark silicon, which absorbs heat dissipated by the active circuitry. This, coupled with AMD's use of a soldered heat spreader and aggressive binning (the company claims to use the top 5% of Zeppelin dies), leads to impressive overclocking headroom from our 1920X sample. We maintained a 4.1 GHz overclock, the highest achieved with any Ryzen CPU in our U.S. lab, using a relatively tame 1.42V. 

Ryzen Threadripper 1920X slots into the large price gap between Intel's Core i9-7900X and $600 i7-7820X. Making AMD's solution more interesting is the fact that Intel cuts PCIe connectivity from 44 lanes to 28 as you drop to the Core i7. In comparison, the Threadripper chip boasts 64 lanes, though four are reserved for AMD's chipset. The extra I/O comes in handy for multi-GPU configurations, large PCIe-based storage arrays, and streamers using dedicated capture cards.

The 1920X and 1950X both feature 32MB of L3 cache sliced into 16MB per Zeppelin die. You do lose 2MB of L2 cache to the four disabled cores, leaving 512KB per core, or 6MB across the MCM, active. Despite the disabled cores and cache, AMD still rates its 1920X with a 180W TDP.

Enthusiasts have to love that AMD uses Indium solder instead of the thermal paste Intel employs. Threadripper's large IHS helps with heat too, and the chip generally features solid thermal performance. We haven't encountered any serious heat concerns with the Threadripper models, which we can't say for Intel's Skylake-X CPUs. 

Threadripper features independent dual-channel memory controllers, one paired with each die, that combine to provide quad-channel support with varying data transfer rates based upon memory types and DIMMs per channel. The platform supports ECC memory and a functional limit of 256GB of DDR4, though it can support up to 2TB as memory capacity increases.

The distributed memory alignment, along with the latency imposed by traversing the fabric between two separate dies, creates unique challenges for applications sensitive to timing. AMD has also discovered that certain games won't fire up with all of Threadripper's cores enabled. So the company implemented a pair of toggles that enable either UMA or NUMA mode to mitigate memory latency concerns, and a Legacy setting to disable one CCX, solving compatibility issues.

Selectable Creator and Game modes provide users with performance profiles tailored for either content creation or gaming. We covered how the underlying architecture responds to these modes in our AMD Ryzen Threadripper 1950X review.

We are starting to see dedicated coolers trickle out from leading vendors for AMD's massive 4094-pin TR4 socket. In the interim, AMD also includes an Asetek bracket with all Threadripper models to provide widespread compatibility with existing closed-loop coolers from several vendors.

MORE: Best CPUs

MORE: Intel & AMD Processor Benchmarks Hierarchy

MORE: All CPUs Content