Overclocking

Our Core i9-9900K is good for 5GHz, and we haven't failed to hit that with any board we've tested so far, although some have had niggles getting to its 4.7GHz all-core boost at stock speed. Neither were an issue for the ROG Strix Z390-I Gaming, as it was consistent in our benchmarks and hit 5GHz easily, although it needed a somewhat high 1.28V to there. You can see our full overview of Asus' latest EFI and software here.

Performance Analysis

The overclocked power consumption perhaps alludes to a somewhat inefficient power circuitry, but it's not the highest we've seen from a Z390 motherboard by any means, although it was noticeably higher than the Gigabyte Z390-I Aorus Pro WiFi. Stock speed power numbers were on the money, though, as were M.2 and SATA speeds, with the M.2 heatsink reducing the load temperature of our Samsung 960 Evo by 12°C too.

Unlike the MSI board, there was no lacklustre all-core boosting at stock speed, so the Asus board was a tad faster in the multi-threaded benchmarks such as HandBrake and Cinebench. With an overclock just 300MHz higher than the all-core boost, there are unsurprisingly modest gains once overclocked in most tests too. Finally, audio performance was excellent, as you'd expect from Asus these days, with results not far behind the ROG Maximus XI Hero and slightly better than those on the Gigabyte board.

Conclusion

While it's no Maximus Impact, the ROG Strix Z390-I Gaming with its integrated I/O shield, massive VRM heatsink and well-equipped pair of M.2 ports is probably the most lavish mini-ITX board we've seen from Asus since the former's demise a few years ago. Since then, the ROG Strix boards that have stepped in to offer a more mid-range replacement haven't really offered the kind of wow-factor we were hoping for, but things are a bit different here.

With solid overclocking with our Core i9-9900K, excellent audio performance, a reasonable amount of I/O ports, integrated I/O shield and decent onboard cooling, this is by far the most desirable mainstream mini-ITX board out there. It's also the closest mainstream mini-ITX board we've seen to the legendary Impact in terms of features, so we can only hope Asus continues down this path in future. For now, while Gigabyte's offering is just as overclockable and much better value, if you want to build the ultimate mini-ITX PC with your mainstream Intel CPU, this is the board you need.