Filling up the SSD with data
For obvious reasons, when an SSD is tested, the drive is always tested as a spare drive, and is generally always empty (no data on the drive) during the synthetic benchmarks. There is no other way of having a level playing field for all the SSDs under test. This of course changes during the real world tests we conduct here at Myce.com.
Real users of course don't buy an SSD for it to remain empty, and how full the SSD will eventually become varies from one user to the next. What I thought would be useful is to run tests on the SSDs with real data on the drives, and at different levels regarding how full the drive is.
Myce Sustainable Performance Test
Over the last few months I have been studying countless analyzer traces of real computing workloads, and also developing a test that would accurately emulate and measure how performance is sustained over a period of time. For obvious reasons, it is not possible to test an SSD review sample over several months before publishing a review. The solution was to condense this down to a manageable test, that doesn't take too long to run.
I will make it clear right from the outset that this is not a torture test. Bringing any SSD to its knees is not helpful in the least, as I for one would not use any SSD that had slowed down to crawl, just to prove a point. The Myce Sustainable Performance test, I believe is a tough, but sensible test pattern to use for measuring how an SSD will be behave once it's pushed hard over a period of time.
The test pattern is "workstation" based, and closely emulates a typical video or graphics workstation environment. The results are measured using the same hardware I use for the Myce Reality Suite tests, however, the test data and measuring system use a different method.
With the drive filled to 80% of its capacity, I already have an SSD with a lot of data on it. Adding to the data that is already there, the "Sustainable Performance" test data is added. This test data is approximately 20GB is size, so once this is added the SSD is pretty full.
The test is then run for a period of 20 minutes. 60 performance measurements are taken for every minute of the test, and an average performance figure is generated after each minute. At the end of the test I have 20 performance measurements which are then used to generate the graph below.
The faster SSDs will obviously sustain more writes then the slower SSDs. For the fastest SSD in this test, the test pattern generated 146GB of writes, and 193GB of data was read from the SSD during the test.
When reading the graph, you should not pay too much attention to which drive is the fastest, but instead look at the sustainable performance curve of each SSD, as this is what this test is all about.
For the SSD that I am reviewing, I will also add a second graph which looks at the result in more detail.
So let's look at the results.
Sustainable Performance test
Detailed results for the review drive
There is evidence of a slight slowdown in the performance of the Toshiba OCZ VX500 SSD. It doesn’t slow down by a huge amount; in fact it is the region of only 11 MB/s.
Let’s head to the next page for an in depth analysis of power consumption and efficiency...........