AnandTech Storage Bench 2013

When Anand built the AnandTech Heavy and Light Storage Bench suites in 2011 he did so because we did not have any good tools at the time that would begin to stress a drive's garbage collection routines. Once all blocks have a sufficient number of used pages, all further writes will inevitably trigger some sort of garbage collection/block recycling algorithm. Our Heavy 2011 test in particular was designed to do just this. By hitting the test SSD with a large enough and write intensive enough workload, we could ensure that some amount of GC would happen.

There were a couple of issues with our 2011 tests that we've been wanting to rectify however. First off, all of our 2011 tests were built using Windows 7 x64 pre-SP1, which meant there were potentially some 4K alignment issues that wouldn't exist had we built the trace on a system with SP1. This didn't really impact most SSDs but it proved to be a problem with some hard drives. Secondly, and more recently, we've shifted focus from simply triggering GC routines to really looking at worst-case scenario performance after prolonged random IO.

For years we'd felt the negative impacts of inconsistent IO performance with all SSDs, but until the S3700 showed up we didn't think to actually measure and visualize IO consistency. The problem with our IO consistency tests is that they are very focused on 4KB random writes at high queue depths and full LBA spans–not exactly a real world client usage model. The aspects of SSD architecture that those tests stress however are very important, and none of our existing tests were doing a good job of quantifying that.

We needed an updated heavy test, one that dealt with an even larger set of data and one that somehow incorporated IO consistency into its metrics. We think we have that test. The new benchmark doesn't even have a name, we've just been calling it The Destroyer (although AnandTech Storage Bench 2013 is likely a better fit for PR reasons).

Everything about this new test is bigger and better. The test platform moves to Windows 8 Pro x64. The workload is far more realistic. Just as before, this is an application trace based test–we record all IO requests made to a test system, then play them back on the drive we're measuring and run statistical analysis on the drive's responses.

Imitating most modern benchmarks Anand crafted the Destroyer out of a series of scenarios. For this benchmark we focused heavily on Photo editing, Gaming, Virtualization, General Productivity, Video Playback and Application Development. Rough descriptions of the various scenarios are in the table below:

AnandTech Storage Bench 2013 Preview - The Destroyer
Workload Description Applications Used
Photo Sync/Editing Import images, edit, export Adobe Photoshop CS6, Adobe Lightroom 4, Dropbox
Gaming Download/install games, play games Steam, Deus Ex, Skyrim, Starcraft 2, BioShock Infinite
Virtualization Run/manage VM, use general apps inside VM VirtualBox
General Productivity Browse the web, manage local email, copy files, encrypt/decrypt files, backup system, download content, virus/malware scan Chrome, IE10, Outlook, Windows 8, AxCrypt, uTorrent, AdAware
Video Playback Copy and watch movies Windows 8
Application Development Compile projects, check out code, download code samples Visual Studio 2012

While some tasks remained independent, many were stitched together (e.g. system backups would take place while other scenarios were taking place). The overall stats give some justification to what we've been calling this test internally:

AnandTech Storage Bench 2013 Preview - The Destroyer, Specs
  The Destroyer (2013) Heavy 2011
Reads 38.83 million 2.17 million
Writes 10.98 million 1.78 million
Total IO Operations 49.8 million 3.99 million
Total GB Read 1583.02 GB 48.63 GB
Total GB Written 875.62 GB 106.32 GB
Average Queue Depth ~5.5 ~4.6
Focus Worst-case multitasking, IO consistency Peak IO, basic GC routines

SSDs have grown in their performance abilities over the years, so we wanted a new test that could really push high queue depths at times. The average queue depth is still realistic for a client workload, but the Destroyer has some very demanding peaks. When we first introduced the Heavy 2011 test, some drives would take multiple hours to complete it; today most high performance SSDs can finish the test in under 90 minutes. The Destroyer? So far the fastest we've seen it go is 10 hours. Most high performance SSDs we've tested seem to need around 12–13 hours per run, with mainstream drives taking closer to 24 hours. The read/write balance is also a lot more realistic than in the Heavy 2011 test. Back in 2011 we just needed something that had a ton of writes so we could start separating the good from the bad. Now that the drives have matured, we felt a test that was a bit more balanced would be a better idea.

Despite the balance recalibration, there is just a ton of data moving around in this test. Ultimately the sheer volume of data here and the fact that there's a good amount of random IO courtesy of all of the multitasking (e.g. background VM work, background photo exports/syncs, etc...) makes the Destroyer do a far better job of giving credit for performance consistency than the old Heavy 2011 test. Both tests are valid; they just stress/showcase different things. As the days of begging for better random IO performance and basic GC intelligence are over, we wanted a test that would give us a bit more of what we're interested in these days. As Anand mentioned in the S3700 review, having good worst-case IO performance and consistency matters just as much to client users as it does to enterprise users.

We are reporting two primary metrics with the Destroyer: average data rate in MB/s and average service time in microseconds. The former gives you an idea of the throughput of the drive during the time that it was running the Destroyer workload. This can be a very good indication of overall performance. What average data rate doesn't do a good job of is taking into account response time of very bursty (read: high queue depth) IO. By reporting average service time we heavily weigh latency for queued IOs. You'll note that this is a metric we've been reporting in our enterprise benchmarks for a while now. With the client tests maturing, the time was right for a little convergence.

AT Storage Bench 2013 - The Destroyer (Data Rate)

The Vertex 460 is only a hair slower than the Vector 150 in our Storage Bench 2013. The difference actually falls into the margin of error, so it seems that in spite of the lower clock speed, the performance is essentially the same.

AT Storage Bench 2013 - The Destroyer (Service Time)

Performance Consistency & TRIM Validation Random & Sequential Performance
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  • blanarahul - Wednesday, January 22, 2014 - link

    The 250 GB 840 EVO achieves 260 MB/s write speeds. 120 GB EVO achieves 140 MB/s. 500 GB EVO should achieve 520 MB/s bit it only achieves 420 MB/s. Why?? Reply
  • blanarahul - Wednesday, January 22, 2014 - link

    I am talking about non-Turbowrite speeds btw. Reply
  • rufuselder - Thursday, October 9, 2014 - link

    OCZ Vertex 460 is one of the worst options for storage out there in my opinion (each time I try it out, I get just as disappointed). /Rufus from http://www.consumertop.com/best-computer-storage-g... Reply
  • DanNeely - Wednesday, January 22, 2014 - link

    Having more NAND dies to multiiplex IO over only helps for some parts of the write process; and the more of them you have the less adding still more will help because other factors dominate more of the total time (Amdahl's law). As a result going to 500 from 250 gives less of a percentage boost than going to 250 from 120.

    I suspect in the case of the 500, because all the mid/top end drives are clustering in a narrow performance band, that SATA III bottlenecking is coming into play in addition to limitations within the SSD itself.
    Reply
  • blanarahul - Wednesday, January 22, 2014 - link

    Gee thanks. BTW, SATA III maxes out around 540 MB/s for writes. So it's a controller/firmware limitation. Reply
  • Gigaplex - Wednesday, January 22, 2014 - link

    It's not that simple. You don't have to hit maximum utilisation to start feeling the limitations of SATA III. Reply
  • lmcd - Thursday, January 23, 2014 - link

    I thought there weren't more packages but rather larger packages? If I'm wrong then yeah it's probably SATA limitations but if not it's because it's the same bandwidth allocated per packages as previously. Reply
  • lmcd - Thursday, January 23, 2014 - link

    *weren't more packages once 250 GB is met, in the case of this model. Reply
  • Novuake - Wednesday, January 22, 2014 - link

    Simple. Diminishing returns + limitations of SATA III. Reply
  • Shadowmaster625 - Wednesday, January 22, 2014 - link

    It is amazing Toshiba would sully their own name by placing it next to "OCZ". Reply

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