Very slow write speed on SSD S3520

[DRobi14]

I have experienced horribly slow write performance on both my S3520 240GB drives on Windows 7, and would like some guidance.

The details:

I have 4 Intel SSDs : 2 x 530 Series (SSDSC2BW120A4 and SSDSC2BW240A4), and 2 x S3520 240GB (SSDSC2BB240G7). I have the same very disparate performance with both pairs. In addition, I have 3rd S3520 in the field with the same problem.

The pair I will highlight is as follows:

530 Series 120GB

F/W version : DC32

S/N: PHD A41 660 0Z8 120 7GN

DC S3520 240GB

F/W version : N2011021

S/N: BTD V72 750 FRY 240 AGN

The problem: I have a proprietary OS running on a Pentium server box, which has its own driver to talk to these SSDs in IDE mode. The 530 performs very well, in line with benchmark data I can find on the Web. The S3520 performs well also, except In certain cases, where its average sector write time is 26x (yes, 26) that of the 530. We have managed to produce a specific test case where we write 15,634 single sectors of a 13MB file, with specific content in each sector, and the same non-consecutive order of disk addresses being written. The average write time for sector writes to the 520 is 0.06ms, and the average write time for the S3520 is 1.56ms.

At first we thought there must be some compatibility problem between our disk driver and this specific drive.

But I have constructed a Windows program which writes these same sectors to a second pair of drives, in the same order, on Windows 7 (using FILE_FLAG_NO_BUFFERING).

The result is the same: < 1 sec to write the 15,634 sectors on the 530, and > 20 sec on the S3520.

I can only conclude that the S3520 has some severe firmware problem which makes it sensitive to the content (and/or the order) of certain data being written.

Does anyone have any experience with similar problems here?

[DRobi14]

Eugenio,

Not certain I know how to read my private messages - how do I do that?

If by "private messages" you mean those sent to my profile e-mail address, mailto:dave@pebbleridge.com dave@pebbleridge.com, I'm getting messages there. But otherwise, please advise how to read "private messages".

thanks

[idata]

Hi DLRobinson,

Thanks for the reply. We would like to inform you that the Intel® SSD DC S3520 Series has lower stats for the Sequential Read and write than the Intel® SSD 530 Series. You can check the comparison here: https://ark.intel.com/compare/75611,93008The Intel® SSD DC S3520 has the following stats: *Sequential Read (up to): 295 MB/s*Sequential Write (up to): 250 MB/sThe Intel® SSD 530 Series has the following stats: *Sequential Read (up to): 540 MB/s*Sequential Write (up to): 480 MB/sThat is why you have slower write speeds with the Intel® SSD DC S3520. Please bear in mind that it is a Data Center SSD and it has higher endurance than the Intel® SSD 530 Series. Regards, Junior M.