Resolved Suddenly, slow AHCI write speeds...

[Zeke D]

So in the past, I was getting somewhere around 500 - 700 write, and ~1200 read, but lately, I'm getting 150 - 250 write and ~1200 read. It's a Samsung SM951 in a 16x PCIe adapter in slot #2. I grabbed my spare 4x adapter- results the same. I moved it to a different slot- results the same. I've done a PRAM reset, tried it in single-user mode. Anything else I should try?

 

[tsialex]

So in the past, I was getting somewhere around 500 - 700 write, and ~1200 read, but lately, I'm getting 150 - 250 write and ~1200 read. It's a Samsung SM951 in a 16x PCIe adapter in slot #2. I grabbed my spare 4x adapter- results the same. I moved it to a different slot- results the same. I've done a PRAM reset, tried it in single-user mode. Anything else I should try?

Just force TRIM. Boot into single user mode and run fsck -fy. It's a know problem of some firmware revisions of SM951-AHCI.

 

[Zeke D]

Oh, that’s right. It probably undid that when I did an update or something.
[doublepost=1543620339][/doublepost]And, done. Thanks, Alex.