If you saw the 8 core/ 16 thread AMD Ryzen 7 release as an awesome opportunity for building hardware-accelerated virtual desktops with IOMMU, you were not alone. On the AMD X370 chipset motherboards, we were able to get multi-GPUs working. At the same time, if you are not going to be physically present at the system, it may be tempting to utilize a lower cost AMD B350 platform. Many of these B350 platforms cost under $100 so paired with a $329 AMD Ryzen 7 1700 with cooler, it is an awesome value proposition. We have a few B350 platforms in the lab and decided to try a multi-GPU setup.
AMD Ryzen IOMMU and the B350 Chipset Challenges
Here is the video showing a common example of what we find using AMD Ryzen IOMMU and the B350 chipset. It is disappointing:
This particular setup worked with the Gigabyte AX370-Gaming 5 platform and booted into the OS without issue. On the B350 platform, it cause an AMD-Vi error before the system was fully booted.
We used the particular test setup below for the video, but this is not solely an ASUS B350 issue. We have B350 boards from three different vendors all exhibiting this issue.
- CPU: AMD Ryzen 7 1700 with stock cooler
- Motherboard: ASUS Prime B350-Plus
- GPUs: AMD RX 480 (Gigabyte) and AMD RX 470 (ASUS STRIX)
- RAM: 32GB DDR4 2x 16GB Patriot Viper DDR4-2666 at DDR4-2133 to limit potential causes of errors
- Chassis: NXZT S340 vanilla with 2x the case fans (pulled from the S340 Elite build)
- PSU: Seasonic 750W
- OS: Ubuntu 16.04.2 with Kernel 4.10.1 (guide here to update)
A lot has been made about AMD Ryzen ECC support at launch. Since we now have several Ryzen test platforms we are managing demos on, the discussion on ECC memory, at this point, is misplaced. There are a myriad of platform issues that still need to be ironed out, such as this AMD Ryzen B350 IOMMU issue, memory support, and OS kernel patching, before one will need to worry about ECC memory on the Ryzen platform. We do think that the AMD Ryzen platform will be a winner in the low-end 1P server market several months from now when the platform matures and we get appropriate motherboards (e.g. with iKVM and IPMI.) Although we do advise against buying these systems today for mission-critical services, we have told executives at AMD and multiple server vendors that these will be category killer 1P server platforms if a mature platform hits the market.