Hello everyone, I am going to be transplanting my desktop PC bits into a Sliger CX4200e 20 inch deep case with two 5.25inch bays. I want to populate the two 5.25 inch bays with IcyDock SATA backplanes. To do that, with 4 SATA drives per slot I need to add four more SATA ports to my motherboard, a ProArt X670E. Right now I am considering an M.2 to SATA adapter to get me the extra 4 ports I will need.
Some things to consider. There will be a PNY 4090 in PCIe Slot 1 doing CUDA things so I can’t split the two 5.0x16 slots to x8-x8. The remaining PCIe 4x16 slot only has x2 lanes so I am not sure it’s useful for this, but I am ok with being wrong there. There are however three unused M.2 slots, 1 is a PCIe 5.0x4 connected to the CPU I believe, and 2 are PCIe 4.0x4 and connected to the chipset and one of those shares lanes with the 3rd PCIe x16 slot which is only x2
Is the M.2 to SATA adpater my best option? I want to put 8 SSDs in a ZFS pool.
The remaining PCIe 4x16 slot only has x2 lanes so I am not sure it’s useful for this, but I am ok with being wrong there
Grabbing a calculator here. One lane of PCIe4 has a bandwidth of almost 2 GB/s (gigaBytes, not bits). One SATA drive has a maximum of 550 MB/s (but really usually lower, like 450-500). So, even with just two lanes of PCIe4 you’ll be able to saturate all your 8 drives.
But that’s in theory. In practice - you’re going to put a PCIe-to-SATA bridge chip in the middle anyway, and that will always have it’s own limits. So always check on what chip this or that card or adapter works. Lot’s of them don’t work with speeds higher than PCIe 2.0 for example
If the motherboard does not have a SAS port, I would say yes, if you have the m.2 slots to spare the m.2 adapters are the most space efficient solution.
Two other options exist though; one is to buy a regular PCIe expansion card, I do believe you have already looked at this route:
The other is SATA over USB, in case you have two internal and unused USB headers:
This is much more jank however and performance will be lacking since it is USB 2.0 to SATA…
Not really, though it is a mechanically and thermally fragile way of getting enough bandwidth for three SSDs. I’d use the two x2 slots for ASM1166 cards and put a fan on them.
Yeah. Problem is there aren’t any PCIe 4.0 x2 HBAs, though since it’s an x2(16) slot a Broadcom 9500-8i will fit. Lots of drawbacks even if it supports x2, which I’m not sure it does, though.
I’ve used adapters with ASM1166 chips on x1 and x4 physical connectors, in both M.2 and PCIe format. They have only PCIe3.0x2 bandwidth as said above, so don’t expect a board with 5 or 6 SATA ports to get more than the PCIe3.0x2 2GB/s-ish speed.
Yup. More specifically, the ~1.7 GB/s upper end I see from the ASM1166 is much the same as what @aBav.Normie-Pleb’s reported. It varies by some tens of MB/s depending on drive configuration and activity so, if the last few percent are important, I wouldn’t necessarily plan on more than 1.6 GB/s per x2 connected ASM1166.
Currently, I have 4 SATA SSDs in a RAIDZ1 and get anywhere from 900+MB to 1.2GB and that’s enough for my use case. I am after redundancy, and space, more than I am after speed and the speed I have now is just fine.