I was thinking to go with a ProArt Z790-CREATOR WIFI which gives my 16 length lanes with x8, x8, x4 or x16 and x4. I’d like to put an RTX 2000 Ada in this build so that would take x8. From what I can tell four SFF 8643 cables are needed for the backplane in the HL15 (or other configuration but still usually four cables.) LSI 9400-i16 seems to be the recommended HBA but it requires x16.
I’m not quite sure why all that bandwidth would be needed for 15 HDDs, I’m currently using an LSI 9300-8i for 27 drives with a supermicro backplane and it’s just reaching the point where it’s a bottleneck. Would I be OK to run the LSI 9400-i16 in a x16 width PCIe slot with 8 lanes and 15 HDDs? For reference I’d be using the other 4 lanes to add an SFP+ NIC and I’d have two Samsung PM983 in the M.2 slots plus a small T500 for the OS.
Welcome @manofoz! I believe the answer is yes but I don’t have personal experience with this. I’m also seeing 9400-16i cards in x8 form factor. The data sheet for one of those linked below leads me to believe it’ll work even with PCIe x1.
45Drives doesn’t do expander/multiplexed backplanes. I think some of the early Backblaze pods used them and they were problematic. 45Drives gives you a direct/simple SAS 12Gb/s channel to each drive. Expanders will definitely be a bottleneck in resilvers and scrubs I think, at least they seemed to be on my SuperMicro.
Correct, at least to use all 15 bays.
Where do you see that it requires x16? Most HBA cards have a physical x8 connector (PCIe 3 or 4 depending on the generation), and will negotiate an electrical x4 if they need to, at reduced throughput.
Yes. I have an HL15 containing a B650 ProArt Creator with a 9300-16i and an RTX 4070 Ti Super bifurcated x8/x8 running just fine. A x8 PCIe 4.0 connection has a theoretical throughput of 32 GB/s. Even with 15 12Gb/s SAS SSDs, you wouldn’t max that out, let alone a group of SATA HDDs operating at 1/6 that.
Thanks! That’s my bad, I was confused because the 8i card I have is x8 so I associated the 16i with being x16 but that is indeed not the case. That works great for me then.
Next question for me is if I pull the trigger and go with a 12th gen intel CPU or wait to see what the 15th gen motherboards look like.
The suffixes refer to the number of SAS lanes and whether the connectors are (i)nternal or (e)xternal (on the PCIe bracket). Even the 9600-24i (Three SFF-8654 connectors which have 8 SAS lanes each) has a PCIe x8 connector. There are some variants in the 94/95/9600 series that do have a physical PCIe x16 connector, but those have a W in the name, like 9405W-16i or 9600W-16e. I think the variants with x16 PCIe edge connectors are mainly intended for NVMe drive arrays.