Desktop PC – Synthetic Benchmarks
As its name suggests AS SSD was developed specifically to
measure the performance of SSDs. It measures Sequential Read and Write
performance with an IO Size of 16MB and a Queue Depth of 1. It measures Random
4K Read and Write for a Queue Depth of 1 and for 64 Threads. 64 Threads
generates a Queue Depth of 64 (please note that SATA drives support a maximum
Queue Depth of 32, so they are at a disadvantage in this test to NVMe devices,
which support queue depths of 128 or more). The Access Time AS SSD reports is
for 512Byte sequential reads and writes.
The 4K random Reads and Writes performance is particularly
relevant to a drive’s ability to act as a Windows system drive. I use the
default test file size of 1GB.
AS SSD produces a score for Read Performance, Write
Performance and an Overall Score.
The scores are calculated as –
Overall score = (Seq Write x 0.15) + (Seq Read
x 0.1) + (4K Read * 2) + 4K Write + 4K-64Thrd Write + (4K-64Thrd Read * 1.5)
Read score = (Seq Read * 0.1) + 4K Read + 4K-64Thrd
Write score = (Seq Write *0.1) + 4K Write + 4K-64Thrd
For Client SSDs, I feel that there should be an
even greater loading given to the Queue Depth 1 4K Read and 4K Write results
but nevertheless AS SSD is a quick and useful benchmark. I always use a 1GB test
file. We would expect a modern SATA SSD to achieve an overall score of
The latest version of AS SSD can be downloaded here.
Here is the AS SSD result for the SX950U –
Here is a comparison of the overall AS SSD score with the
other products I have tested –
A good score
Anvil’s Storage Utilities
Anvil’s Storage Utilities tests Sequential Reads and Writes
with an IO Size of 4MB, Random 4K Reads and Writes at Queue Depths of 1, 4 and
16 and Random 32K and 128K Writes.
The scores are calculated as –
Overall Score = Read Score + Write Score
Read Score = (Seq 4MB = MB/s x 1) + (4K = MB/s
x 4.5) + (4K QD4 = MB/s x 2.75) + (4K QD16 = MB/s x 1.75) + (32K = MB/s x 1) +
(128K = MB/s x 1.5)
Write Score = (Seq 4MB = MB/s x 1) + (4K =
MB/s x 4) + (4K QD4 = MB/s x 3) + (4K QD16 = MB/s x 3)
I always use a Test size of 1GB and 100%
The latest version of Anvil’s Storage
Utilities can be downloaded here.
Here is the Anvil result for the SX950U –
Here is a comparison of the Anvil Total score with the other
products I have tested –
Another good score.
Crystal Disk Mark
Crystal Disk Mark is a widely respected benchmark, which is
often used by manufacturers as a basis for publishing their ‘headline’
sequential read and write speeds. I always run the test with One Thread and a
Queue Depth of 32 (which generates a Queue Depth of 32, being the maximum Queue
Depth supported by SATA drives), a 1GB test file, Random data and 3 or 5
passes. The benchmark performs sequential IO with an IO Size of 512K for the
Seq Q32T1 test, sequential IO with an IO Size of 1MB for the Queue Depth 1 Seq
test and Random IO with an IO Size of 4K for the 4K (Queue Depth 1) and the 4K
Crystal Disk Mark can be downloaded here (I use the
Here is the CDM result for the SX950U –
You can see that the headline Sequential Read Speed, as
specified by Toshiba, of 560 MB/s has been surpassed but the headline Sequential
Write Speed of 520 MB/s has not.
The ATTO benchmark tests Sequential IO for a large range of
IO Sizes. I always run the test with the default Queue Depth of 4.
ATTO can be downloaded here.
Here is the ATTO result for the SX950U –
Again, the headline Sequential Write speed, as specified by Adata,
has not been achieved.
Now let’s head to the next page, to look at the results
for the Desktop PC Real World Benchmarks…..