The Supermicro X11SPA-T Review: An Impressive Cascade Lake Workstation Motherboard

System Performance

Not all motherboards are created equal. On the face of it, they should all perform the same and differ only in the functionality they provide - however, this is not the case. The obvious pointers are power consumption, but also the ability for the manufacturer to optimize USB speed, audio quality (based on audio codec), POST time and latency. This can come down to manufacturing process and prowess, so these are tested.

Power Consumption

Power consumption was tested on the system while in a single ASUS GTX 980 GPU configuration with a wall meter connected to the Thermaltake 1200W power supply. This power supply has ~75% efficiency > 50W, and 90%+ efficiency at 250W, suitable for both idle and multi-GPU loading. This method of power reading allows us to compare the power management of the UEFI and the board to supply components with power under load, and includes typical PSU losses due to efficiency. These are the real world values that consumers may expect from a typical system (minus the monitor) using this motherboard.

While this method for power measurement may not be ideal, and you feel these numbers are not representative due to the high wattage power supply being used (we use the same PSU to remain consistent over a series of reviews, and the fact that some boards on our test bed get tested with three or four high powered GPUs), the important point to take away is the relationship between the numbers. These boards are all under the same conditions, and thus the differences between them should be easy to spot.

There is some variance in our power consumption figures of the Supermicro X11SPA-T motherboard as we are using a 12-core Intel Xeon W-3235 chip which has a rated TDP of 180 W. This didn't make much difference in idle and long idle power states, however, it became more apparent at full load with a maximum power draw from the wall of 255 W. 

Non-UEFI POST Time

Different motherboards have different POST sequences before an operating system is initialized. A lot of this is dependent on the board itself, and POST boot time is determined by the controllers on board (and the sequence of how those extras are organized). As part of our testing, we look at the POST Boot Time using a stopwatch. This is the time from pressing the ON button on the computer to when Windows starts loading. (We discount Windows loading as it is highly variable given Windows specific features.)

As our charts suggest, professional focused models such as the Supermicro X11SPA-T have a much slower POST time than desktop models. This is due to the chipset, controller count, and the type of controllers used including three Ethernet controllers. We achieved a POST time at default settings of 87 seconds, although after disabling as many controllers as the firmware would also us, we managed 69.5 seconds.

DPC Latency

Deferred Procedure Call latency is a way in which Windows handles interrupt servicing. In order to wait for a processor to acknowledge the request, the system will queue all interrupt requests by priority. Critical interrupts will be handled as soon as possible, whereas lesser priority requests such as audio will be further down the line. If the audio device requires data, it will have to wait until the request is processed before the buffer is filled.

If the device drivers of higher priority components in a system are poorly implemented, this can cause delays in request scheduling and process time. This can lead to an empty audio buffer and characteristic audible pauses, pops and clicks. The DPC latency checker measures how much time is taken processing DPCs from driver invocation. The lower the value will result in better audio transfer at smaller buffer sizes. Results are measured in microseconds.

None of the boards we have tested so far has been optimized for DPC latency out of the box, and the Supermicro X11SPA-T achieved a DPC latency of 295 microseconds. This is still under our 300 microsecond recommendation, but barely.