Is 400 to 500 MB/s correct for SAS1 RAID0?

Discussion in 'RAID Controllers and Host Bus Adapters' started by digity, Nov 20, 2018.

  1. digity

    digity New Member

    Joined:
    Jun 3, 2017
    Messages:
    22
    Likes Received:
    1
    I picked up an old external SAS/3.0 Gbps DAS enclosure to tinker with. It has a built-in Adaptec AIC-9410 SAS controller with external SAS connectors (SFF-8088). I set up a RAID0 set with 4 (four) basic off the shelf SATAIII/6.0 Gbps 7200 RPM HDDs and then later another RAID0 set with 4 (four) basic off the shelf SATA/6.0 Gbps SSDs. I attached the enclosure to my test machine with a LSI SAS9201-16i HBA 6 Gbps HBA controller (in IT/initiator target mode) and HP SAS Expander (which has the external SAS/SFF-8088 connection). Using ATTO Disk Benchmark I got roughly 450 MB/s read & 425 MB/s write for the HDD set and 480 MB/s read and 450 MB/s write for the SSD set. Are these on par with real world throughput for SAS1/3.0 Gbps (which is essentially SATAII/3.0 Gbps)? If not, what's the bottleneck/issue?

    P.S. - There are some details that I'm not 100% sure impact the above speeds...:
    1. 2 (two) of the 4 (four) SSDs in the RAID0 group are rated at 340 MB/s read and 100 MB/s (the other two are rated 550 MB/s and 475 MB/s, read and write respectively)
    2. The HP SAS Expander is rated at 6.0 Gbps for SAS drives and 3.0 Gbps for SATA drives. I know the drives are all SATA, but I'm not sure how if it sees the RAID volumes the enclosure presents as SAS or SATA since it's coming over a SAS port
     
    #1
  2. i386

    i386 Well-Known Member

    Joined:
    Mar 18, 2016
    Messages:
    1,451
    Likes Received:
    331
    I think it's the combination of sas 1 controller + hp expander.
    The older firmware revision of hp expander had problems with negotiating sata speed and fell back to a lower sata speed.
     
    #2
  3. digity

    digity New Member

    Joined:
    Jun 3, 2017
    Messages:
    22
    Likes Received:
    1
    Any idea what speed/throughput is normal for SAS1/SATAII 4x HDDs and 4x SSDs in RAID0?
     
    #3
  4. i386

    i386 Well-Known Member

    Joined:
    Mar 18, 2016
    Messages:
    1,451
    Likes Received:
    331
    Hard to answer without knowing which devices are used.
     
    #4
Similar Threads: MB/s correct
Forum Title Date
RAID Controllers and Host Bus Adapters Dell Perc H310 + 7x 3TB 7200RPM = only 400-450MB/s? Apr 12, 2018
RAID Controllers and Host Bus Adapters Crossflashed 9341-8i to 9300-8i - limited to 200MB/s!? Jul 5, 2016
RAID Controllers and Host Bus Adapters LSI 9266-8i + 8x SSD RAID-0 - Limited to 800 MB/s Jul 5, 2014
RAID Controllers and Host Bus Adapters Correct way to set up storage for home. Aug 15, 2016
RAID Controllers and Host Bus Adapters Intel SASUC8I, is this setup correct? Nov 19, 2011

Share This Page