Even disregarding the hype around compact ITX enclosures these days, most brands don't tend to provide unique mATX-based enclosures. That form factor doesn't seem to be loved by those building their own systems, as they mostly either go ATX or ITX. The form factor between those is usually more the go-to for system integrators, which has most mATX enclosures on the market cater to those, resulting in simple designs that just work.

The SilverStone Alta G1M is a refreshing change in that landscape. Designed to take up as much space as an ITX case on your desk, the slim and tall enclosure flawlessly marries SFX-based power with the mATX form-factor while taking advantage of the additional space to provide the ability for any GPU to fit alongside a 360 mm radiator setup. On top of that, the internal layout makes assembly extremely easy with every major component being accessible even with the system fully assembled.

Even with the unique layout, SilverStone has managed to provide thoughtful and functional elements that make assembly even easier. From the hooks for zip ties to the four Velcro strips on the cable cover and the PSU bay that sits flat against the vented rear of the case, the Alta G1M doesn't feel like an extraordinary case when assembling things as it is just quick and easy.

The SilverStone Alta G1M is clearly meant to utilize AIOs, but you may also opt for tower coolers of up to 159 mm in height, so air-cooling advocates have plenty to pick from to build a potent system as well. The Air Penetrator fan works well with a noticeable feel of warm air exhausting though the top, but it isn't the quietest fan at the classic fan curve we use in our tests. That said, this brand-new Air Penetrator 184i PRO pushes a lot more air than traditional fans of this size, so you should spend the time to flatten the speed curve in your BIOS. In other words, there is realistically no need to have it run at full throttle. As you can see by the short list of negatives above, this case really has no tangible drawbacks as an mATX enclosure.

In the end, the SilverStone Alta G1M is a refreshingly new take on an mATX enclosure that could even entice ITX users who really want to go for that 360 mm radiator.