This is quite interesting, and a bit of a gotcha, I think
I had a single PCIE 3.0 x1 slot spare and had just removed a load of PCs from a training room, each with 500GB SSDs. So I thought, I’d plug in a 4 port SATA controller to the PCIE3.0 x1 slot, and plug the 4 SSDs into it. I did so, and have created a Strip 0 pool, as the data is only temporary, and can be recreated very easily.
Basically the data is stored on spindle hdds, copied to the SSDs, accessed there as “It’s quick”, then moved off every 7 days or so as it’s replaced by new data.
But I think I’ve made a mistake. So I’m putting it here for all to see and hopefully not repeat.
The SSDs are in a raid 0, so in theory their combined bandwidth would be 560MB x4 = 2.24 GB / second. but a PCIE x1 slot’s max speed is 985 MB/s, so my SSDs can overload the channel.
I think it’s interesting, annoying, but interesting. If they weren’t in raid 0 It wouldn’t matter as much.
Any thoughts? Am I right?
Oh yes, these are things a person MUST think about when designing a system and to meet any requirements, and that does include the pool layout as that is critical as you mentioned above. I have a 4 port SATA card but it requires a PCIe x2 connection. Even with todays fast PCIE 5 speeds, bandwidth must be taken into consideration. NVMe drives can connect up directly to the PCIe lanes, Full Speed Ahead! The limiting factor is either the PCIe bus speed or the NVMe speed.