I have eight identical drives connected to an LSI 9207-8i ASRock X470 Taichi Ultimate mainboard.

They’re currently all running badblocks -b 8192 -c 2048 -p 0 -s -t 0 -v -w /dev/disk/by-id/ata-WDC_WUH722424ALE6L4_[XXXXXXXX] each.

While sda and sdb achieve almost 300MB/s, sdg and sdh struggle to even get to 200MB/s. That’s a 50% difference!

All of my drives are recognized as SATA3, confirmed by smartctl -a /dev/sd[a-h] | grep SATA showing SATA Version is: SATA 3.5, 6.0 Gb/s (current: 6.0 Gb/s)

There’s no CPU bottleneck either AFAICT:

Any idea what could be the issue of that? Is such a dramatic speed difference to be expected of Ultrastar drives?
Are these drives just bad?

Edit: Mainboard configuration:

Edit2: Okay, apparently the ASM1061 which provides the two extra SATA3 ports is connected to the CPU via a single PCIe 2.0 x1 lane, which provides only 4gbps (=500MB/s) of raw throughput.
I think I have found the culprit and the problem should disappear once I connect the drives to my LSI 9207-8i HBA card.

  • cabillaud@lemmy.worldEnglish
    2·
    3 hours ago

    What are “d/s” and “f/s”?

    E: I rtfm and… It’s discard requests and flush requests

  • CompactFlax@discuss.tchncs.deEnglish
    56·
    11 hours ago

    Without googling the specs, are those two on a different channel? ie the chipset has 6 and then another chip handles 2 or vice versa

    • Tolstoy@lemmy.worldEnglish
      20·
      11 hours ago

      While browsing the manual you’re on point. I bet the 2 drives are plug into SATA3_A1 and A2. These 2 are handled by an ASMedia ASM1061

    • jrgd@lemmy.zipEnglish
      13·
      11 hours ago

      Based on OP’s edit, that looks correct. Unless OP checks the topology and can make the claim that drives from the main chipset are the slow ones, secondary chipset drives will tend to perform slower, and the ASMedia ASM1061 has several reports online of poor to trash performance compared to baseline.

      Best bet if the full performance is necessary out of every drive would be finding a decent quality PCI-E SATA III riser card that doesn’t use a known flawed driver chip rather use the two ‘extra’ ports on the motherboard.

  • northendtrooper@lemmy.caEnglish
    11·
    9 hours ago

    As a dude from the peanut gallery still learning, this was an interesting read. Never thought about the importance of what channel the sata cables are plugged into.

    • MuttMutt@lemmy.worldEnglish
      3·
      7 hours ago

      It’s one of the reasons why getting a SAS controller is really nice, backplanes make it even better.

      I was preforming a burn with 10 X 8TB drives on a controller that already had a couple operating ZFS pools totaling 18 X 4TB drives and a couple SSD’s and there was no slow downs. A SAS3008 controller can support over 6000 MB/s and has a PCI Express X8 3.0 bus.

      I’ve been building my servers and network out of old enterprise gear for a while now. It uses more power but the things you can do are truly amazing. Sadly the ai boom drove prices way up compared to a couple years ago, what I bought for 900 in 2024 is running around 1500 today.