The Asus Prime Z270-A & GIGABYTE Z270X-Ultra Gaming Motherboard Review

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 MSI GTX 770 Lightning GPU configuration with a wall meter connected to the Corsair AX1200i power supply. This power supply is Platinum rated, and as I am on a 230-240 V supply, leads to ~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.

Peculiarly, there is a significant difference in the power consumption between the two motherboards. The power consumption of the Asus Prime Z270-A is relatively high for a Z270-based board with a Kaby Lake CPU, but the culprit behind the slightly elevated consumption figures clearly is the onboard lighting, as the energy consumption figures drop by nearly 10 Watts once the lighting is turned off, giving the values above. GIGABYTE’s Z270X-Ultra Gaming displayed highly elevated energy consumption readings, surpassing even those of most previous generation motherboards that we have tested. Disabling the lighting did not bring the consumption down near to that of the other motherboards and no components were getting abnormally hot to justify the consumption as efficiency losses, suggesting that the high consumption may be due to a software/BIOS power management error.

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.) 

The default boot time of both the Asus Prime Z270-A and the GIGABYTE Z270X-Ultra Gaming is very good, with 12.6 seconds for the former and 13.4 seconds for the latter. With the fast boot option enabled, the Asus Prime Z270-A goes past the boot process in 10 seconds flat. Fast boot again does not work for GIGABYTE, as the enabling fast boot on the Z270X-Ultra Gaming is having the same effect that it does on most modern GIGABYTE motherboards - it multiplies the boot time instead of reducing it. 

Rightmark Audio Analyzer 6.2.5

Rightmark:AA indicates how well the sound system is built and isolated from electrical interference (either internally or externally). For this test we connect the Line Out to the Line In using a short six inch 3.5mm to 3.5mm high-quality jack, turn the OS speaker volume to 100%, and run the Rightmark default test suite at 192 kHz, 24-bit. The OS is tuned to 192 kHz/24-bit input and output, and the Line-In volume is adjusted until we have the best RMAA value in the mini-pretest. We look specifically at the Dynamic Range of the audio codec used on board, as well as the Total Harmonic Distortion + Noise.

We expected to see good audio performance figures from both of the motherboards that we are testing today, as both are making use of the new Realtek ALC1220 codec (or ASUS's variant, the ALC1220A). The GIGABYTE Z270X-Ultra Gaming displayed exceptional performance figures, massively outperforming its Z170-based predecessor, with the dynamic range reaching 104.2 dB(A) and THD + Noise hitting -88.1 dB(A). The performance figures of the Asus Prime Z270-A are even better, with the motherboard displaying the best onboard audio performance that we have seen until today. 

USB Backup

For this benchmark, we transfer a set size of files from the SSD to the USB drive using DiskBench, which monitors the time taken to transfer. The files transferred are a 1.52 GB set of 2867 files across 320 folders – 95% of these files are small typical website files, and the rest (90% of the size) are small 30 second HD videos. In an update to pre-Z87 testing, we also run MaxCPU to load up one of the threads during the test which improves general performance up to 15% by causing all the internal pathways to run at full speed.

Due to the introduction of USB 3.1, as of June 2015, we are adjusting our test to use a dual mSATA USB 3.1 Type-C device which should be capable of saturating both USB 3.0 and USB 3.1 connections. We still use the same data set as before, but now use the new device. Results are shown as seconds taken to complete the data transfer.

The new ASMedia 2142 controller works wonders on both of the motherboards that we are testing today, with a copy time of 3.4 and 3.3 seconds for the Asus Prime Z270-A and the GIGABYTE Z270X-Ultra Gaming respectively. Attaching the drive to a USB 3.1 Gen 1 (USB 3.0 PCH) port brings the copy time up to 5.6/5.7 seconds, which are the expected figures for the capabilities of this interface.

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.

Asus usually takes DPC latency very, very seriously and the Prime Z270-A is no exception, with the maximum reading being just 43 μs. GIGABYTE used to have problems here but the Z270X-Ultra Gaming performed very well, with the maximum latency reaching 161 μs, a good figure for a modern gaming motherboard. Usually anything above 200 μs throws up a flag or two.