ASUS X870/X870E Motherboard Roundup & VRM Analysis

VRM Analysis

VRM’s or phases are by far one of the biggest factors in what defines what category a motherboard fits into, and ASUS really does have a broad range of options here. Most boards ranging from the more budget-focused up to the high-end typically come with an 8-layer PCB design, while the Mini-ITX board has a 10-layer PCB, which is more robust and uses more copper for improved signal integrity, enhanced power delivery, and better thermal management so higher VRM configurations tend to be mounted on thicker PCB designs.

The Mini-ITX STRIX X870-I Gaming WIFI features the smallest VRM configuration of the ASUS X870 lineup, obviously with it being a smaller motherboard. It uses a 10+2+1 configuration, which is more than enough to ensure the most powerful CPUs can hit their boost clocks.

However, pushing bigger overclocks, and ensuring your system can maintain those boost clocks for extended periods, such as while rendering video, you’ll benefit from a more comprehensive VRM configuration, and more so still, from one that can be cooled efficiently. For these, you’ll find the Prime X870-P WIFI comes with a 14+2+1 configuration, while the X870E-Creator WiFi comes with 16+2+2.

For gamers, again you’ll likely spend long periods with the CPU under heavy usage, which is why the STRIX boards all typically have 16+2+2 configurations like the -A gaming, so similar to the Creator-WiFi.

The -E and Crosshair Hero expand upon that further though to 18+2+2. The TUF X870-PLUS is also very similar, coming in with 16+2+1 phases.

While the number of phases can be key for providing adequate power to the CPU’s Vcore, SOC and miscellaneous components, the rated power also has a key impact and ASUS have again stepped up their game here with the Vcore phases and SOC phases predominantly using SPS phases or smart power stages.

The PRIME X870-P WiFI instead though uses DrMOS which combines a MOSFET driver and one or more MOSFETs in a single package and are generally found with synchronous buck converters.

Sometimes we do find, like with the TUF board and Creator-WiFi board a mixture of SPS and DrMOS phases depending on the delivery design and what works more efficiently and is more cost effective as well.

Power wise, we find the TUF and PRIME board using 80A stages, while the -A increases beyond that to 90A across VCore, SOC and miscellaneous while the higher-end STRIX boards increase this to 110A for a more powerful solution though as we all know, this, much like we saw on X670 and X670E, is well beyond what’s needed, even with a flagship CPU with an overclock.

In terms of which MOSFETs are used, ASUS use a variety of brands including Vishay SIC850A 110A phases for the -E, Hero and -I boards, SiC629 DrMOS 80A phases for the -P WiFi and MPS MP86670 80A phases for the likes of the Creator-WiFi and TUF PLUS-WiFi, though for the miscellaneous phases on some of the boards, like the Creator-WiFi, they’ve gone with ALPHA & OMEGA AOZ53071QI 80A stages instead.

Then for the controller of choice, for the most part, ASUS seem to have plumped for the DIGI+ PWM controller from Infineon which is sometimes mounted on the front of the board for the higher-end, and the rear of the board on the higher-end of the scale. This ranges from the ASP2205, 2206 or 2308 controllers.