AkG
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IOMETER
Unfortunately when it comes to IOMeter, this drive does not perform as well as hoped nor as well as the other synthetic tests would lead you to believe. While tests like Crystal DiskMark can tell you the POTENTIAL power a drive has, IOMeter (when configured like we have it) is actually a much better predictor of real world performance.
In our usual IOMeter test we are trying to replicate real world use where reads severely outnumber writes. However, to get a good handle on how powerful the controller is we, we have also run an additional test. This test is made of 1 section at que depth of 1. In this test we ran 100% random. 100%writes of 4k size chunks of information. In the past we found this tests was a great way to check and see if stuttering would occur. Since the introduction of ITGC and / or TRIM the chances of real world stuttering happening in a modern generation SSD are next to nill; rather the main focus has shifted from predicting "stutter" to showing how powerful the controller used is. By running continuous small, random writes we can stress the controller to its maximum, while also removing its cache buffer from the equation (by overloading it) and showing exactly how powerful a given controller is. In the .csv file we then find the Maximum Write Response Time. This in ms is worst example of how long a given operation took to complete. We consider anything higher than 350ms to be a good indicator that the controller is either relying heavily on its cache buffer to hide any limitations it possess or the firmware of the controller is severely limiting it.
This truly is disappointing but it does go a long, long way to explaining why IOMeter didn’t like this drive as much as it “should” have (when based on the results from previous synthetic tests). This drive's controller has without a doubt a big problem and it is now obvious why Toshiba opted for that over sized cache: it simply needs it to perform!
We can say that in testing and daily use we never noticed any extended pauses; rather the drive just didn’t have that “snappiness” that other modern generation solid state drives have. As with all things computer related, just because it has a theoretical problem does not mean it is a noticeable problem. So with this in mind we are going to withhold judgment for the time being and consider these results nothing more than the Toshiba controller not liking our IOMeter tests. After all, you the end user do not care HOW a solid state drive does what it does, as long as you never notice it doing going about its business Though to be honest, we do have to wonder how much this issue is going to effect the real world performance of the SSDNow V+.
IOMETER
IOMeter is heavily weighted towards the server end of things, and since we here at HWC are more End User centric we will be setting and judging the results of IOMeter a little bit differently than most. To test each drive we ran 5 test runs per HDD (1,4,16,64,128 que depth) each test having 8 parts, each part lasting 10 min w/ an additional 20 second ramp up. The 8 subparts were set to run 100% random, 80% read 20% write; testing 512b, 1k, 2k,4k,8k,16k,32k,64k size chunks of data. When each test is finished IOMeter spits out a report, in that reports each of the 8 subtests are given a score in I/Os per second. We then take these 8 numbers add them together and divide by 8. This gives us an average score for that particular que depth that is heavily weighted for single user environments.
Unfortunately when it comes to IOMeter, this drive does not perform as well as hoped nor as well as the other synthetic tests would lead you to believe. While tests like Crystal DiskMark can tell you the POTENTIAL power a drive has, IOMeter (when configured like we have it) is actually a much better predictor of real world performance.
IOMeter Controller Stress Test
In our usual IOMeter test we are trying to replicate real world use where reads severely outnumber writes. However, to get a good handle on how powerful the controller is we, we have also run an additional test. This test is made of 1 section at que depth of 1. In this test we ran 100% random. 100%writes of 4k size chunks of information. In the past we found this tests was a great way to check and see if stuttering would occur. Since the introduction of ITGC and / or TRIM the chances of real world stuttering happening in a modern generation SSD are next to nill; rather the main focus has shifted from predicting "stutter" to showing how powerful the controller used is. By running continuous small, random writes we can stress the controller to its maximum, while also removing its cache buffer from the equation (by overloading it) and showing exactly how powerful a given controller is. In the .csv file we then find the Maximum Write Response Time. This in ms is worst example of how long a given operation took to complete. We consider anything higher than 350ms to be a good indicator that the controller is either relying heavily on its cache buffer to hide any limitations it possess or the firmware of the controller is severely limiting it.
This truly is disappointing but it does go a long, long way to explaining why IOMeter didn’t like this drive as much as it “should” have (when based on the results from previous synthetic tests). This drive's controller has without a doubt a big problem and it is now obvious why Toshiba opted for that over sized cache: it simply needs it to perform!
We can say that in testing and daily use we never noticed any extended pauses; rather the drive just didn’t have that “snappiness” that other modern generation solid state drives have. As with all things computer related, just because it has a theoretical problem does not mean it is a noticeable problem. So with this in mind we are going to withhold judgment for the time being and consider these results nothing more than the Toshiba controller not liking our IOMeter tests. After all, you the end user do not care HOW a solid state drive does what it does, as long as you never notice it doing going about its business Though to be honest, we do have to wonder how much this issue is going to effect the real world performance of the SSDNow V+.
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