I've been interested in building a DIY NAS out of an SBC for a while now. Not as my main NAS but as a backup I can store offsite at a friend or relative's house. I know any old x86 box will probably do better, this project is just for the fun of it. The Orange Pi 5 looks pretty decent with its RK3588 chip and M.2 PCIe 3.0 x4 connector. I've seen some adapters that can turn that M.2 slot into a [few SATA ports](https://www.amazon.com/SilverStone-Technology-ECS07-Expansion-SST-ECS07/dp/B0B8TV1QRG/ref=sr_1_1?crid=1F2JKUZR7D8MI&keywords=ECS07&qid=1695671791&sprefix=ecs07%2Caps%2C138&sr=8-1&ufe=app_do%3Aamzn1.fos.18630bbb-fcbb-42f8-9767-857e17e03685) or even a [full x16 slot](https://www.amazon.com/ADT-Link-Extender-Graphics-Adapter-PCI-Express/dp/B07YDH8KW9?th=1) which might let me use an HBA. Anyway, my question is, assuming the CPU isn't a bottle neck, how do I figure out what kind of throughput this setup could theoretically give me? After a few google searches: - PCIe Gen 3 x4 should give me 4 GB/s throughput - that M.2 to SATA adapter claims 6 ~~GB/s~~ Gb/s throughput - a single 7200rpm hard drive should give about 80-160MB/s throughput My guess is that ultimately, I'm limited by that 4GB/s throughput on the PCIe Gen 3 x4 slot but since I'm using hard drives, I'd never get close to saturating that bandwidth. Even if I was using 4 hard drives in a RAID 0 config (which I wouldn't do), I still wouldn't come close. Am I understanding that correctly; is it really that simple?