DM8168 writing to SATA SSD slow

Marthinus Potgieter

Hello

I am attempting to interface a custom board with a DM8168 processor to an SSD through the SATA interface. My particular application requires a sustained write speed of 40MB/s to the SSD.

The SATA interface is initialised correctly and the link is established at 3Gbps. After this an application starts writing data to the SSD. What I see is that the write process seems to stall sporadically. It sometimes stops writing to the SSD for up to 5s, and then continues again. This causes buffer overruns in the rest of my system.

If I replace the SSD with a normal HDD I achieve the desired write speed easily and none of the write stalls happen. I am using an EXT4 filesystem.

Any idea why this could be happening?

EZSDK version: 5_05_02_00

PSP version: 4.04.00.01

Regards

Cobus Potgieter

over 11 years ago

0 _Ralph_ over 11 years ago

Guru 10685 points

Have you tried using a different SSD? Try with and without TRIM commands. Try using smartctl to diagnose problems with the SSD.

Ralph

0 Marthinus Potgieter over 11 years ago in reply to _Ralph_

Prodigy 20 points

Hi Ralph

Thank you for the response.

I tested with a different SSD family and I do not experience the same problems.

Where do I enable / disable the use of the TRIM commands?

I will follow your advice to use smartctl to try and determine where the problem lies.

Regards

Cobus

0 _Ralph_ over 11 years ago in reply to Marthinus Potgieter

Guru 10685 points

I believe you can use fstrim but I'd suggest googling "trim ssd linux" to see how to do it.

Ralph

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DM8168 writing to SATA SSD slow