I was looking at N class CPU builds and very quickly realized they're not for me. For storage only over LAN, low power prioritized use they're a valid play, but there are some tradeoffs that are not obvious at first glance.
See those NVMEs he stuck in there? They're running at 1/8th their rated link speed. Yeah...12.5%. (PCIe 4.0 x4 vs PCIe 3.0 x1). This board is one of the better ones on pcie layouts [0], but 9 gen3 lanes is thin no matter how you look at it so all those boards have to cut corners somewhere on that
I decided I'm better off with a ebay AM4 build - way better pcie situation, ECC, way more powerful cpu, more sata, cheaper, 6x nvme all with X4 lanes, standard fan compatibility. Main downsides being no quicksync, power consumption and fast ECC UDIMMS are scarce. That was for a proxmox/nas hybrid build though so more emphasis on performance
Hmm good point. But to make sure I understand you completely, this only really matters for compute-heavy workloads, right?
Yes, mostly. PCIE 3.0 x1 lane gets you 500mb/s [1] not much point to it compared to a regular ssd on sata3 which could do 600mb/s. So if you want very fast storage you would also think about it.
Realistically for your DIY stuff you're talking a different beast to these NASs. Bang for your buck you'd be attaching the mass 3.5" storage in an external second hand JBOD enclosure and the main device would be dealing with the faster storage and have an HBA to connect to it.
[1] edit: as Havoc pointed out I need my coffee should be 2gb/s which does change the point.
Not quite. A gen 3 lane is 1 GB/s link speed
Better question is how the article is getting 1.2 on fio tests. That must be a testing artifact
With NAS builds you're usually network constrained. Most of the numbers you see on storage side are gigabytes while network is gigabits. i.e. 1/8th
So if you crunch the numbers you'll see storage (esp flash) is much faster than network, meaning NAS can cut corners on storage. If you're running something like a VM that accesses the storage directly then suddenly storage speed matters