Hey folks. I just ordered my HL15 chassis + backplane a day ago and now I’m figuring out what I’m going to put in it.
My planned usage:
Primarily storage - I plan to store hundreds of thousands of hours audio - ingesting about 24GB / day. I also plan to read all of it remotely from another machine on the same network multiple times a day.
I think I’m going to be optimizing for storage space + transfer speed.
I think I need a bit of a sanity check on my list of parts. I’m used to working with consumer parts but this is my first time building something enterprisey from scratch.
You won’t need a CPU that powerful just to serve files, even at 40gbps. The fastest access to files will always be locally. I’ll ask the dumb question, just to be sure; the other machine has some proprietary software or hardware, or for some other reason needs to be physically separate from the HL15 and can’t be run in/on it either directly in the OS or a VM solution?
Do you know what’s the minimum I can get away with for saturating 40gbps (assuming everything else is in place)? I thought a 7402p was being conservative.
The reason I’m keeping them separate is because the box doing all the processing is going to have multiple GPUs and I don’t think they’d fit in my HL15 after I add networking, storage add-in cards and the HBA.
My main point was just about CPU cores. You’ll probably find the CPU running at only a few percent of load. The CPU doesn’t have to do a lot when reading the disks or sending data over the network. A bit like some gaming builds that don’t really need a powerful CPU because the GPUs are doing the majority of the workload. It seems like the HBA and NIC you listed are both PCIe 3 x8 cards, so in a sense the minimum would be any CPU that supports that, since you haven’t defined much of any additional workload (transcoding, encryption, VMs, …). I would think even the HL15 “Full Build”, even though the CPU used has 1/15th the compute of your Epyc, can still push data around about the same. Having more compute available is certainly not a bad thing. I didn’t go with the full build. But, if someone wants to come in and correct me that’s fine.
That’s what I thought. Just felt like I needed to ask.
As Fossil said, the bottleneck isn’t going to be with the HBA or the NIC or the CPU. It’s going to be with the “spinning rust”. A single Seagate Exos X22 lists a maximum sustained throughput of 285MB/s. That’s very much ‘best-case’. A typical sustained transfer rate for a 7200 RPM drive is more like half of that. You can have some data cached in RAM or SSD, and the drives have a small cache, but a 4-disk RAID 0 is only going to return data at say a typical sustained (4 disks * 125MB/s * 8 bits/byte =) 4 Gb/s. I think you’d be better off with fifteen 6TB or 8TB drives than four 20TB drives. Even then that might only put you in the 15-20 gbps range. 15K rpm drives might get you to 25 gbps. To get to 40, I think you’d need dual actuar disks, SSDs, or a chassis like the 45Drives Q30 or something from a different company like Supermicro that has 24 or 36 3.5" drive bays.