MP 1,1-5,1 SAMSUNG EVO 970 PROBLEMS

[Alan Young]

I know this is not a Mac Pro specific problem. But the folks here know all kinds of good stuff and can hopefully point me in the right direction.

I have two Samsung Evo 970 +. They were both working the same on an I/O Crest card. Both had read/write speeds around 2300 write and 2500 read. Something changed ( I know not what) that one is now reading/writing at half of that speed. Looking in System information on my 5,1 it shows one with a link width of 4x and the other with a link width of 2x. I don't know what change them. I printed a system report from a week ago and both were a link width of 4x. What could have changed for one of the drives to be at 2x link width as opposed the the 4x it previously was? It's interesting that whatever change occurred, it wasn't visible to me. Any ideas?

Thanks in advance.

Alan

 

[KeesMacPro]

You could swap the blades between eachother on the I/O Crest to find out if the card or one of the blades is the culprit.
Before swapping them, take note which blade runs at 1/2 speed .

 

[Alan Young]

You could swap the blades between eachother on the I/O Crest to find out if the card or one of the blades is the culprit.
Before swapping them, take note which blade runs at 1/2 speed .

Thanks for the suggestion. I have done this and it is just one blade that is the culprit. Swapping the blade to the other port results in the problem with the blade and not the port. It is quite interesting that the lanes swapped between 4x to 2x. I would like to figure out why! Just using the computer the half speed reduction isn't very noticable, but transferring large files, video manipulation, etc it is very noticeable. I just tried an Ablecon PEX-2 with the same ASMedia chipset and the results are the same. Problem follows the drive.

 

[KeesMacPro]

Well, could be worse : the I/O Crest...
Strange though!
Could it be that the blade was regularly running hot ?

 

[Alan Young]

Well, could be worse : the I/O Crest...
Strange though!
Could it be that the blade was regularly running hot ?

No, I have had it since new. I use iStat monitors and have alerts when any temp exceeds a threshold one sets. I don’t think it has ever been above 52C.
It happened after a reboot. I was looking for something else in system report and noticed it. Very strange to me.
Thanks for the suggestion and if I can figure anything out I will let you know.

Alan