MSI Cubi 2 Kaby Lake UCFF PC Review

Power Consumption and Thermal Performance

The power consumption at the wall was measured with a 1080p display being driven through the HDMI port. In the graphs below, we compare the idle and load power of the MSI Cubi2-005B with other low power PCs evaluated before. For load power consumption, we ran the AIDA64 System Stability Test with various stress components, as well as our custom stress test with Prime95 and Furmark, and noted the maximum sustained power consumption at the wall.

Even though Kaby Lake-U is touted to be very power efficient (and has been proved in some of the preceding sections), it looks like the BIOS could do with some tweaks for better idle power consumption. On the load side, we found Prime95 + Furmark providing the higher sustained power consumption number, as shown below in our thermal stress routine.

Our thermal stress routine starts with the system at idle, followed by four stages of different system loading profiles using the AIDA64 System Stability Test (each of 30 minutes duration). In the first stage, we stress the CPU, caches and RAM. In the second stage, we add the GPU to the above list. In the third stage, we stress the GPU standalone. In the final stage, we stress all the system components (including the disks). Beyond this, we leave the unit idle in order to determine how quickly the various temperatures in the system can come back to normal idling range. The various clocks, temperatures and power consumption numbers for the system during the above routine are presented in the graphs below.

We repeated the same observations with our legacy stress test using the latest versions of Prime95 and Furmark - Prime95 v28.10 for 30 minutes (after launching with the max. stress option), followed by Furmark v1.18.20 for 30 minutes. The Prime95 load is then removed, allowing just the GPU alone to be stressed for 30 minutes. The system is then left idle.

According to the official specifications, the junction temperature of the Core i7-7500U is 100 C. We find that the temperature is briefly reached with the Prime95 AVX2 workload. The package power also goes upwards of 20W in this case. However, the power limitation soon kicks in, and the package power is held stable at 15W throughout the stress workload. In the case of the AIDA64 SST (which is not pure AVX2 for the CPU stress case, but, more of an all-round test case), the package power is never more than 15W, and the  core temperature stays around 80C.

On the whole, the Cubi 2's thermal solution is geared for a 15W TDP CPU. This is acceptable for almost all consumer use-cases, but, results in the performance numbers of the BRIX-series with cTDP-Up SKUs being better.