Random Read Performance

One of the major changes in our 2015 test suite is the synthetic Iometer tests we run. In the past we used to test just one or two queue depths, but real world workloads always contain a mix of different queue depths as shown by our Storage Bench traces. To get the full scope in performance, I'm now testing various queue depths starting from one and going all the way to up to 32. I'm not testing every single queue depth, but merely how the throughput scales with the queue depth. I'm using exponential scaling, meaning that the tested queue depths increase in powers of two (i.e. 1, 2, 4, 8...). 

Read tests are conducted on a full drive because that is the only way to ensure that the results are valid (testing with an empty drive can substantially inflate the results and in reality the data you are reading is always valid rather than full of zeros). Each queue depth is tested for three minutes and there is no idle time between the tests. 

I'm also reporting two metrics now. For the bar graph, I've taken the average of QD1, QD2 and QD4 data rates, which are the most relevant queue depths for client workloads. This allows for easy and quick comparison between drives. In addition to the bar graph, I'm including a line graph, which shows the performance scaling across all queue depths. To keep the line graphs readable, each drive has its own graph, which can be selected from the drop-down menu.

I'm also plotting power for SATA drives and will be doing the same for PCIe drives as soon as I have the system set up properly. Our datalogging multimeter logs power consumption every second, so I report the average for every queue depth to see how the power scales with the queue depth and performance.

Iometer - 4KB Random Read

While the other SSDs hover at 60-90MB/s for random reads, the SM951 provides a rather noticeable upgrade at 108MB/s. 

Samsung SM951 512GB

Looking at the performance more closely reveals that the SM951 delivers better performance at all queue depths, although obviously the difference is at high queue depths where the SM951 can take advantage of the faster PCIe interface. The SM951 actually does over 150K IOPS when the MB/s is translated into throughput.

 

 

 

Iometer - 4KB Random Write

Random write performance is equally strong. The line graphs shows how the SM951 shifts the whole curve up, implying a performance increase at all queue depths. Especially the performance at queue depths of 1 and 2 are noticeably better than on other drives.

Samsung SM951 512GB
AnandTech Storage Bench - Light Sequential Performance
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  • blanarahul - Tuesday, February 24, 2015 - link

    Can't wait to see what Intel brings to the table considering the amount of focus they put on consistency. Reply
  • extide - Tuesday, February 24, 2015 - link

    I'm not sure that we will see anything too interesting client side from them. They seemed to have moved all their focus to the enterprise side, which is of course where the bulk of the money is.

    FWIW, Intel already has a PCIe SSD that is arguably faster -- the Intel SSD DC P3700
    Reply
  • dylan522p - Tuesday, February 24, 2015 - link

    Is, not arguably Reply
  • Stuka87 - Wednesday, February 25, 2015 - link

    It is faster, and certainly more reliable. Intel has the best enterprise SSDs on the market. Reply
  • FunBunny2 - Wednesday, February 25, 2015 - link

    -- Intel has the best enterprise SSDs on the market.

    Among consumer facing companies, perhaps. The real enterprise SSD/flash players are largely unknown to AnandTech and its readers.
    Reply
  • monsted - Wednesday, February 25, 2015 - link

    I'd love to see the results of a HDS FMD compared to the usual suspects. Reply
  • Kristian Vättö - Wednesday, February 25, 2015 - link

    We've had this conversation before and I'll tell you this again: the majority of flash array vendors are using SSDs from Intel, SanDisk, Samsung and others. There are some that design and build their own drives/blades (e.g. Violin and Skyera), but the vast majority is using third party drives as the heart of their flash arrays. Reply
  • GTVic - Wednesday, February 25, 2015 - link

    All drives now should support eDrive. Reply
  • Railgun - Tuesday, February 24, 2015 - link

    At the rate I'm going, I'll end up with one of these before my XP941 ever gets powered up once, retail or otherwise. Reply
  • Laststop311 - Tuesday, February 24, 2015 - link

    Disappointed in lack of 1TB size/ no 3d vnand/ no nvme. I planned on using 1 of these in 1TB size for a boot drive for a skylake-e build. The good news is I have a couple years for samsung to fix those issues. Reply

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