Possible storage expansions

Hey all!

I'm looking to replace my kinda aging old laptop that serves as a NAS at the moment. Due to some very specific software, I'm looking for a small footprint Intel SBC.

Right now the UP² seems to be the best option, but before preordering, I wanted to make sure I could use it for all I need.

I'm aware that it has a SATA-III port, an M.2 E-key slot, and an mPCIe slot. I'm exploring possible use of all these together to have a 4- or 6-bay NAS built around the board.

One HDD is simple enough, pop it onto the SATA-III header. One can add up to four more HDDs using an mPCIe card that has a controller and four SATA-II interfaces (SATA-III is already way too much bandwidth for a regular HDD as it can't usually make use of the 600MB/s throughput. Best 3.5" HDDs top out around 300MB/s, and that is at reading.), providing up to 500MB/s speeds. Say, I have three HDDs there, giving each roughly 150MB/s.

However there's the E-keyed M.2 slot. It is PCI-e 2x, meaning twice as much throughput as the mPCIe interface. As I found no information on the version of PCIe used on the UP², I'll go with the assumption that it uses v1.x, which would result in a total of 2GB/s total throughput. If we could connect a SATA controller onto that, with either an SAS port or a vertical extender board with up to 4 SATA-III ports, we could have up to 8 HDDs connected to this bad boy!

As there aren't many consumer-level devices that expose PCIe interfaces in general, and I personally know a few people who'd kill for such a solution, I think it might be a market to break into. There are some people, mostly tinkerers, who want a low-power, but powerful NAS solution. Stronger NAS builds cost a stellar amount of money and support 2-4 drives, maximum. They are big and noisy, and eat power like cops eat donuts. Even a lower-powered Synology NAS eats 60W under load, not counting hard drives.

The UP² eats, in the beefiest config, 20W. Add a few hard drives, say, 6x2.5" regular 9mm laptop drives. The largest usual power draw stops around 2.5W - so 5V 0.5A should be more than enough. This means, at 6 drives, we stop at exactly 15W extra, during heavy load. In total, you have a NAS beating the top-of-the-line Synology models, with half the power requirement, with 6 drives already installed.

I was also looking at the EXHAT port, but by my (limited) understanding, it is more for things like the generic RasPi HATs - sensors, and low bandwidth devices only, nothing heavy-duty storage related.



My question is - would this be a viable plan for a NAS? As for the M.2 card (so far I found no ready-made solution, unfortunately), I have a friend who is pretty good at designing such things, and is totally into the open-source hardware scene, so at worst, we could have a PCB design that could be mass-manufactured even. What do you guys think?