Sata/SAS controllers tested (real world max throughput during parity check)

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23 hours ago, said:

Mostly HBA bus width and link speed, for SAS expanders number of wide ports in use and devices used link speed.



Thank you, I ordered a used LSI-9207e (external ports) from eBay for the R710, and the RES2SV240 for my existing ASRock server.


Would it be ok to order (2x) SFF-8088 to SFF 8088 (for R710 server) and a dual port 8088 to 8087 PCI bracket (for ASRock server) and (2x) SFF-8087 to SFF-8087 from the dual port to the RES2SV240? It’s more expensive and I don’t know if there will be a speed loss going through the dual port. I think it’ll look nicer and not have to route the cables through the PCI slots.


Would it be a faster connection if I just ordered (2x) SFF-8088 to SFF-8087 and route them through the PCI slots to the RES2SV240 directly.

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10 minutes ago, Omar said:

Would it be a faster connection if I just ordered (2x) SFF-8088 to SFF-8087 and route them through the PCI slots to the RES2SV240 directly.

It won't make any difference in speed, just need to respect max SAS cable length.

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  • 1 month later...

The dual controllers in each enclosure are for redundancy/multipath and since Unraod doesn't support SAS multipath you basically have two connection options:


1) single cable from HBA to first controller on the 1st enclosure then daisy chain to 2nd encloure

2) and best option for performance, one cable from each HBA port to each enclosure

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  • 3 months later...
On 4/27/2019 at 2:04 PM, Lev said: this is a tremendous resource and was interested in your thoughts on what would be the expected speeds to determine the optimal configuration for a for 30+ drives in the following configuration:


SuperMicro SuperStorage 6047R-E1R36L configured as:

  • BPN-SAS2-846EL1 (front 24 bays) with three 8087 connectors
  • BPN-SAS2-826EL1 (rear 12 bays) with two 8087 connectors
  • LSI 2308 SAS2 PCIe 3.0 host adapter with two 8087 connectors (motherboard integrated)
  • 6x SATA ports on the motherboard, running at 6GB SATA3 (DMI 2.0)
  • 2x NVMe slots via Supermicro AOC-SLG3-2M2 add-in card
  • The drives are all WD Red/White 10TB & 8TB models

Unraid setup as of 4/27/2019:

  • Data disks x28
    • x24 connected to BPN-SAS2-846EL1 dual linked to LSI 2308
    • x4 connected to motherboard SATA ports
  • Parity disk
    • x1 disk connected to motherboard SATA port
  • cache disk
    • x1 NVMe drive connected to AOC-SLG-2M2
  • Not in use/connected
    • BPN-SAS2-826EL1 (rear 12 bays)
    • x1 SATA port
    • x1 NVMe port


Is this the most optimal setup to spread out the utilization and not encounter bottlenecks? Any opportunities for improvement?


If I was to daisy chain a single link from the third 8087 connector on the BPN-SAS2-846EL1 to the downstream BPN-SAS2-826EL1 how much of a negative impact on performance would that have? The 826-EL1 would be empty, no disks. Would that reduce PHYs available or add significant additional SAS overhead?





Upgrading both the 846 and 826 backplanes to SAS3. Such an easy swap in Supermicro 847 case.

This has been such a helpful resource, and I stumbled across your posts over on another message board about your benchmarks with sas3 that were helpful in knowing what performance to expect with sas3 and databolt. I wanted to post here to say thanks for that. Also if there was anything you wanted to update in your first post here to reflect your most up to date findings.


I'll post some pics of the backplane swap when I get a chance. It's been fun.

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  • 1 month later...

Maybe this helps to understand why 10 Port SATA cards with Port Multiplier Controllers are so bad and how it is possible to use a little bit more bandwidth by not using all of their SATA ports:


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