The power circuit a motherboard is very important if you're planning to overclock. Not only the amount of phases is important, but the parts of the power circuit (the PWM controller and MOSFETs) are also very important. Motherboards have different power circuits and are therefore more or less suited for overclocking.
The best power circuit out of the boards tested is found on the ASUS Strix Z270G Gaming. Despite the fact that the power circuit is supposed to be a downgrade compared to last generation's RoG boards, the power circuit is still comparable to power circuits found on the ATX boards from the Strix and Pro series from ASUS. Furthermore, the heatsinks have been mounted with screws, which is a sturdier construction with improved heat dissipation.
The power circuit found on the ASRock Z270M Extreme4 is also fine. It's not as good as the one found on the ASUS board: the heatsinks have been mounted using push-pins and the PWM controller is not a digital one, however it has excellent components in all other areas. The four MOSFETs for the VCore are 87350D DSMs from Texas Instruments, products with a very good reputation. They're usually found on extremely high-end boards. The MOSFETs for the IGP, IO and SA are not quite as good in terms of quality and can also be found on lower positioned boards (such as the ASRock Z270 Killer SLI) - however the MOSFETs on the last two components are mainly important if you're overclocking the memory. The Extreme4 should therefore be well-suited for CPU overclocking, even though the power circuit is not quite as good as the one on the ASUS board due to the push-pins and the PWM controller.
The MSI and Gigabyte feature less phases and components and therefore you probably won't be able to overclock as well with them, however it's hard to determine a clear winner out of the two. The main advantage of the MSI board is that its heatsinks are mounted with screws instead of push-pins.
|Motherboard||Phases||Primary PWM controller||Type||MOSFETs||MOSFET rating||Mounting heatsinks|
|ASRock Z270M Extreme4||7||Intersil ISL95856||4 + 3 Phases||Texas Instruments 87350D (VCore)||40 A||Push-pins|
|ASUS Strix Z270G Gaming||10||Digi+ ASP1400BT||?||ON Semiconductor 4C06B + 4C09B||52 + 69 A||Screws|
|Gigabyte Z270M-D3H||6||Intersil ISL95866||4+2 Phases||ON Semiconductor 4C06N + 4C10N||69 + 49 A||Push-pins|
|MSI Z270M Mortar||6||RichTek RT3606BC||
|NIKO-SEM PK616BA + PK632BA||50 + 88 A||Screws|
Cooling and overclocking features
The most important aspect for overclockers is the presence of fan headers, since good airflow is absolutely necessary for overclocking. Most boards come with more than enough of them, however this generation ASUS is no longer the only manufacturer to support PWM on (nearly) all fan headers. MSI and Gigabyte from previous generations usually had one or two PWM fan headers, even the highest positioned models. Now all fan headers on MSI and Gigabyte boards support PWM, even on the lowest positioned models. This is very nice to see!
Otherwise there aren't any outstanding overclocking features on the Micro-ATX boards. Voltage measure points, problem diagnosis and buttons are all not present. The amount of fan headers is also not too different on the boards: the ASRock and ASUS boards have five of them, whereas the Gigabyte and MSI only have four. With the exception of the ASRock board all fan headers on all boards support PWM.
|Motherboard||Fan headers (PWM)||Problem diagnosis||Power/reset buttons|
|ASRock Z270M Extreme4||5 (3)||No||No|
|ASUS Strix Z270G Gaming||5 (5)||No||No|
|Gigabyte Z270M-D3H||4 (4)||No||No|
|MSI Z270M Mortar||4 (4)||No||No|