I am testing my DC S3500 SSD. I found the write iops and read iops are all OK.
4K bytes read 7K iops,
4K bytes write: 15K iops
512 bytes read 18K iops
512 bytes write 18K iops
Mixed read /write still alright:
random 4k bytes 50% read, 50% write: 6k iops.
But when I tried write & read-back, i.e. random write but immediate read back from same position, I got terrible figure:
random 4k bytes write then read-back: 1000 iops only.
Is there anything wrong for write&read-back?
According to this documentation: http://www.intel.com/content/dam/www/public/us/en/documents/product-specifications/ssd-dc-s3500-spec... Intel® Solid-State Drive DC S3500 Series - Product Specification the advertised performance is tested with 4K 8K only which matches what you have informed if you meant to write 70.000 IOPS for 4K read.
The Intel® SSD DC S3500 Series are not tested with the type of test that you have mention, therefore, we don't have a point of comparison for that.
However, this type of test is expected to be slower. We advise you to do the test based on the specification noted in the document above.
Thank you Aleki.
I did a little more profiling for the read-back after write. Here's what I got:
2000 write N read-back
Finished in- 4,019,333 micro seconds
write: 253,671 (microseconds)
Reading is about 15 times slow than writing if it is a read-back.
My question is, isn't there an internal cache that the reading should be returned immediately?
The only tests performed on this drive is the one advertised on the online documentation we have sent you in our previous post. We don't have read/write back tests performed on the drive. Is there any particular reason you're doing the test in this way?
My industry requires transactional data storage, like database does. Thus a read-back verification is ideal. I guess SSD itself has some kind of verification inside the box. But we still love to see an explicit read-back verification if possible.
Does Intel has some documents or presentation how the data integrity is done or data error is monitored? Thanks.
BTW, though SSD has data integrity internally, I still need keep around the codes to detect data corruption, as required by regulator. That's why I am testing the read-back. Thanks.
Could you please try this tool called http://www.iometer.org/doc/downloads.html IOmeterhttp://www.iometer.org/doc/downloads.html you can find the information on how to run this tool from page 10 on this http://www.intel.com/content/dam/support/us/en/documents/ssdc/hpssd/ssd-750/sb/intel_ssd_750_series_... guide
Also, could you please use http://crystalmark.info/software/CrystalDiskMark/index-e.html Crystal Disk Mark as well and provide us a screenshot of the results of both tests?
We're following up on your thread since we have not heard back from you.
If you're still interested in continuing with the support, or you issue has been resolved, please let us know.