The ASRock Rack X470D4U represents AMD Ryzen stepping into new territory as a server processor. Readers have been asking us to investigate the platform for some time now. AMD does not offer a supported Ryzen server platform in this space to match the Intel Xeon E-2200 series, but the price/ performance of its chips makes the prospect of using Ryzen attractive to many. This mATX motherboard is available on its own as well as integrated into a pair of 1U barebones systems offered by ASRock Rack. There are two motherboards in this immediate family; the X470D4U which we are reviewing today, and the X470D4U2-2T which we will review later.
ASRock Rack X470D4U Overview
The ASRock Rack X470D4U is a mATX motherboard measuring 9.6” x 9.6”. In that form factor, you get the AM4 socket which accepts any of the Ryzen CPUs. STH first saw this platform at Computex 2019 almost a year ago.
The official CPU support list starts at the Ryzen 2000 series and covers all the way to the top of the 3000 series stack with support for the Ryzen 9 3950X. Officially, this list excludes the first-gen Ryzen 1000 series parts, but I can confirm both the original Ryzen 5 1600 and the Ryzen 5 1600 AF CPU, which is derived from the Zen+ architecture used on the 2000 series CPUs, work without issue. With that information, it is likely the entire Ryzen 1000 line will work as well.
Given the Ryzen CPU, there is dual-channel memory support for up to 4 DDR4 unbuffered DIMMs at speeds up to DDR4-3200. ECC memory support is included, and the relatively new 32GB ECC DDR4 2666 DIMMs are supported, giving a maximum memory capacity of 128GB.
During testing, one problem was encountered with regards to the physical location of the CPU socket in relation to the memory slots. The Ryzen CPU being used for testing was installed with the stock cooler, specifically the AMD Wraith Stealth. The first memory slot on the X470D4U is so close to the CPU socket that it is blocked from use while the Wraith Stealth cooler is installed. The fan on the cooler even makes light contact with the DIMM in the second memory slot.
A taller cooler like the Wraith PRISM would not have this problem, but other Ryzen coolers might encounter difficulty. Also, users with taller DIMMs than we tested with will certainly encounter problems with both slots 1 and 2. For typical server-style passive heatsinks this is not an issue, nor is it for ASRock Rack’s pre-validated heatsinks. Still, for those looking to save money and making an inexpensive edge server (e.g. a NAS) with the stock cooler, this is an important challenge to consider.
Based on the X470 chipset, this motherboard is limited to PCIe Gen3, even when populated by a Ryzen 3000 series CPU that would otherwise support Gen4. There are two PCIe x16 slots and an x8 slot. Only the first top x16 slot can operate at x16 link speeds. The second x16 slot is electrically x8, and if both x16 slots are occupied they automatically operate at x8/x8. The x8 slot between them is electrically x4.
There are also two M.2 slots on board, but neither runs at the maximum PCIe 3.0 x4 speed as you might expect. M2_1 can operate at PCIe 3.0 x2 or SATA3, while M2_2 operates at PCIe 2.0 x4. If you want more PCIe connectivity, we suggest moving to AMD EPYC.
The rest of storage is handled by the 8 onboard SATA3 ports; 6 are provided by the X470 chipset, including one port with support for SATA DOMs. The other 2 SATA3 ports are provided by an Asmedia controller and are not present on the X470D4U2-2T version of this platform.
Rear I/O is limited; only two USB 3.0 ports are exposed. There is a serial port as well as a VGA output driven by the ASPEED AST2500. That AST2500 BMC has its own dedicated NIC above the USB ports, and there are two 1GbE connections powered by an Intel i210AT controller.
That ASPEED AST2500 is the baseboard management controller and is the defining feature of this motherboard. The BMC will allow out of band management of the system, full remote KVM, and mounting of virtual media over the network. Many of STH’s readers will be familiar with the ASPEED brand of BMC, as it is commonly used on Inspur, Supermicro, Gigabyte, and other vendor boards. Its inclusion on a Ryzen board is very nearly unique at this point in time. If you need IPMI support from a Ryzen-based platform to be able to deploy and manage the server remotely, this ASRock Rack X470D4U is one of the only options around. Coupled with the front to back chassis airflow, these are some of the changes made to turn a Ryzen platform into a server platform.
ASRock Rack X470D4U Topology
We wanted to take a quick moment here to show the system topology. We described it in words above but seeing it helps. First, here is the block diagram:
An explanation of that block diagram one can see in our hardware overview above. Here is the topology:
Since this is based on Ryzen, it is a single NUMA node design even when using Zen(+). AMD EPYC 7001 8-core servers, such as those based on the AMD EPYC 7251 had four NUMA nodes which created a lot of inter-die traffic. With Ryzen, one does not have to worry about that these lower-cost platforms.
Next, we are going to look at the CPU options, management, test configuration, and OS testing, before getting to performance and power consumption.