AMD Ryzen Threadripper 1920X & 1950X Review

An X399 Platform Deep Dive

Threadripper has been the talk of the town for two main reasons: it’s massive number of processing threads and the amazing number of PCIe lanes AMD has been advertising. Both of those features have a way of poking Intel right where it hurts since their comparable processors have less threads and significantly fewer available PCIe lanes.

Despite their on-paper superiority, AMD needed to devise a way to maximize their lane allocation and insure bottlenecks didn’t occur when multiple high bandwidth devices all went hunting for data at the same time. Did that happen? I’d say so but even with 60 (no, not 64) Gen3 PCIe lanes, there may still be some ver monir areas of sacrifice. Honestly though, if you ever do max out this platform you need to look beyond the desktop market for upgrades.

Let’s start out right at the top of things with the Ryzen Threadripper processor. I’m going to generalize a bit here since every one of these CPUs from the $999 1950X to the much more affordable 1900X has the exact same allocation. In addition, the way the processors lanes are set up could vary depending on the motherboard vendor’s chosen price point so take anything you see below as a simple example rather than a rule.

Each Threadripper processor has access to 64 Gen3 PCIe lanes, of which four are continually reserved for the CPU to chipset interface. This still leaves an awe-inspiring 60 lanes to play around with, which can be set up as two x16 slots and two x8 slots for up to 4-way GPU setups. However, with both AMD and NVIDIA moving away from consistent support for more than two cards at a time, few if any X399 motherboards will take advantage of a native 16/16/8/8 design. A good example of additional lanes being put to good use can be seen below on ASUS’ X399 Zenith.

There are 12 more lanes that can be used for dedicated PCIe or SATA-based storage devices and spread over three x4 lanes. This gives users access to extremely high bandwidth storage solutions but unfortunately RAID won’t be supported through these ports. The Threadripper processors also support eight native USB 3.1 Gen1 ports and a high definition audio codec.

The X399 chipset itself hasn’t been left out in the cold either since it natively includes connections for up to eight SATA 6Gbps, five USB 3.1 Gen1 and seven USB 2.0 connections. In addition, there are eight PCIe Gen2 lanes available for hooking up secondary devices like a Bluetooth module, more slots for add-in cards and so on. But the operative word here is “up to” for all devices since it is up to the motherboard vendors to enable or disable ports / connection points based on their own designs. What AMD is showing above is simply a “fully enabled” diagram that may be rarely put to use.

In order to see how this all seamlessly blends together, ASUS sent us their $550 (!!!) ROG Zenith Extreme motherboard. It boasts an immense E-ATX form factor and is geared towards overclockers who want to push the already power hungry Threadripper processors to the highest level possible. ASUS has also seen fit to include a highly advanced power delivery system that includes 8 dedicated phases for the CPU, 3 phases for the SOC and two dual phase setups for the quad channel memory. Did I mention it also comes with a loud active cooling solution over the CPU VRMs? Well, ASUS is working on that one….

ASUS addressed all of those CPU-bound PCI-E lanes in an interesting way with the top three PCI-E slots being set up with 16, 8 and 16 lanes respectively. The bottom most slot is a bit of a chameleon since it natively operates at x8 but also shares bandwidth with an onboard U.2 storage connector. If a U.2 drive is plugged in, four lanes will be dedicated to the SSD while the slot will operate at x4 speeds.

Those 12 additional lanes for PCI-E or SATA based storage were a bit more challenging to implement simply because ASUS ran out of physical space on their motherboard. The somewhat novel solution includes a typical M.2 slot hidden beneath the chipset cover and a not-so-typical “DIMM.2” adapter card which plugs into a specially-keyed DIMM slot next to the 24-pin connector. This card can hold a pair of PCIe based M.2 drives and feed each with up to four PCIe lanes.

The rest of the connectors are pretty straightforward since they originate from the X399 chipset. There’s six SATA 6Gbps ports (two were left on the drawing board due to spatial constraints), an Intel LAN controller running from a PCIe Gen2 connection and four USB 3.1 Gen2 connections including a front panel header and a Type-C port on the backplate. ASUS even found a few PCIe lanes to include the mother of all wireless solutions with a 1×1 WiFi AC module and 2×2 MU-MIMO Wireless AC + Bluetooth 4.1 chip.

Unfortunately I’m just scratching the surface of what this motherboard has to offer but we will get to a full review of it soon. At $550 the Zenith Extreme is at the very pinnacle of X399 pricing and feature sets but there will be plenty of other options in lower price brackets as well.