LSI SAS 9300-8e & HGST Ultrastar SSD800MM: 12 Gb/s SAS, Tested

Results: Performance Consistency

Increasingly, we pay close attention to the performance consistency of enterprise-class SSDs. This is what separates a good drive from a great one when all of the corner case testing seems equal. Over the past year, we measured this in terms of large-block transfers in our Enterprise Video Streaming section. Armed with that data and our exclusive analysis, the peaks, valleys, and frequency of each became clear. If you look at the information for long enough, you start to see fingerprints for each drive.

We started with large-block transfers because, in enterprise video applications, if you don't buffer or write data fast enough, you can lose it completely. Random 4 KB transfers are slightly more academic, but they also emulate database transfers pretty well. With this sort of workload, you might not actually lose anything, but your system will certainly slow down.

In the following tests, we subjected HGST's SSD800MM to 25 hours of continuous random 4 KB writes across the entire drive. We recorded the IOPS every second, giving us 90,000 data points. We then zoomed in to the last 60 minutes to more coherently visualize the results.

Not only did we want to look at the write latency on LSI's SAS 9300-8e, but we also want to compare that information to the 6 Gb/s-capable LSI SAS 9207-8i. If you recall from our random write testing, both HBAs easily keep up with the SSD800MM's 66,000 write IOPS.

HGST's drive performs well in both cases. Connected to the SAS 9300-8e, the SSD800MM doesn't post a single data point above 0.55 ms. In fact, 99.97% of the data points are below 0.52 ms, while 95% are under 0.5 ms. On the SAS 9207-8i, 99.98% of the data points fall below 0.55 ms, while 99.88% are below 0.52 ms and 92.7% come in under 0.5 ms.

The SAS 9207-8i produces a slightly tighter concentration of data, where we observe a standard deviation of 0.0142 ms, along with a variance of 0.000201. The SAS 9300-8e has a standard deviation of 0.0157 ms with a variance of 0.00246. In the end, the SAS 9300-8e manages a lower overall average, even though its data isn't as tightly packed.

There's a fairly even distribution of latency from the SAS 9300-8i, between 0.47 and 0.5 ms, with no obvious pattern. This is a really good result that shows that internal operations, such as garbage collection, are not getting in the way of write performance. It probably has a lot to do with the massive amount of over-provisioning (44%) that the SSD800MM enjoys.

Comparing LSI's SAS 9300-8e to Intel's X79 Express using the SSD DC S3700 yields a similar theme as our previous tests. Namely, the integrated SATA controller offers slightly lower latency, though the difference is only a few microseconds.

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  • slomo4sho
    Now only if this technology was viable for home builds. :( Maybe in a couple years?
  • major-error
    The performance and relative maturity of this prototype drive certainly is impressive, but this is what the enterprise space demands.
    At the consumer level though, the article takes on a completely different tone--I would be very surprised if we don't start seeing mention of PCIe4 at/before the top of the next CPU cycle (so, in 24-36 months at most.)
  • raidtarded
    Actually, Adaptec already saturated PCIe 3.0 with 6GB/s. The chart is incorrect, it doesn't take 12Gb/s to saturate the PCIe bus. Well, not for Adaptec.
  • falcompsx
    Remember when mechanical hard drives struggled to saturate their interfaces? Times sure have changed with SSD tech.
  • CaedenV
    1018945 said:
    The performance and relative maturity of this prototype drive certainly is impressive, but this is what the enterprise space demands. At the consumer level though, the article takes on a completely different tone--I would be very surprised if we don't start seeing mention of PCIe4 at/before the top of the next CPU cycle (so, in 24-36 months at most.)


    Ya, my bet is that we will not start to see SATA4 or PCIe4 until Skymont at the earliest. Considering it is looking like Broadwell may be pushed back due to 14nm die shrink issues I would bet that Skymont will have similar issues when moving to 10nm. But at least for home users you can cram 2 SSDs in RAID0 with a proper RAID card and get a little performance boost until then. I guess the only problem is that most people are going to use the onboard Intel RAID for RAID0, which will get you a killer synthetic benchmark, but in practical reality it is really just expanding your volume with very little speed benefit.
  • kj3639
    Go HGST! WOO!!!!
  • bit_user
    * wipes drool off floor *

    That's a quality review of some quality products. I like the insights shared, throughout. I especially appreciated the link to the SATA-Express paper. Thanks!

    MORE REVIEWS LIKE THIS!!
    :)
  • bit_user
    788951 said:
    Actually, Adaptec already saturated PCIe 3.0 with 6GB/s. The chart is incorrect, it doesn't take 12Gb/s to saturate the PCIe bus. Well, not for Adaptec.
    How many ports and how many lanes, though? If it's just a 8-port card, the math doesn't support that, as 6x8 = 48 Gbps, which is less than the 8 x 8 = 64 Gbps that a x8 PCIe 3.0 slot should carry.
  • raidtarded
    It is the equivalent of a nuke bomb compared to the LSI products. It has 24 Native ports.
    328798 said:
    788951 said:
    Actually, Adaptec already saturated PCIe 3.0 with 6GB/s. The chart is incorrect, it doesn't take 12Gb/s to saturate the PCIe bus. Well, not for Adaptec.
    How many ports and how many lanes, though? If it's just a 8-port card, the math doesn't support that, as 6x8 = 48 Gbps, which is less than the 8 x 8 = 64 Gbps that a x8 PCIe 3.0 slot should carry.
  • raidtarded
    It is a 24 port native raid controller. smokes the 4 ports.
  • drewriley
    328798 said:
    788951 said:
    Actually, Adaptec already saturated PCIe 3.0 with 6GB/s. The chart is incorrect, it doesn't take 12Gb/s to saturate the PCIe bus. Well, not for Adaptec.
    How many ports and how many lanes, though? If it's just a 8-port card, the math doesn't support that, as 6x8 = 48 Gbps, which is less than the 8 x 8 = 64 Gbps that a x8 PCIe 3.0 slot should carry.


    The graph is slightly misleading because it includes some assumptions. I mentioned the x8 assumption, and you found the other major one, which limits it to 8 port cards. Also, they list the SAS throughput with 8b/10b taken into account.
  • drewriley
    788951 said:
    It is a 24 port native raid controller. smokes the 4 ports.


    I personally love the Adaptec 72405, it is amazing that they can provide 24 native ports and absolutely amazing sequential performance. But, when you look at external connectivity, there isn't a ton of difference. Adaptec has a version with 16 external ports, or 16x6Gbps, which is 96Gbps. LSI has an 8 port version, which gives you 8x12Gbps, or 96Gbps. While Adaptec allows you to connect more drives without the use of expanders, LSI allows you to get better performance per drive. I really like the fact that we have two companies catering to high-end RAID that offer different solutions, which gives us, the customer, the most flexibility.
  • drewriley
    328798 said:
    * wipes drool off floor * That's a quality review of some quality products. I like the insights shared, throughout. I especially appreciated the link to the SATA-Express paper. Thanks! MORE REVIEWS LIKE THIS!! :)


    Thank you, I appreciate the feedback!