OWC EXPRESS 4M2: Must remount drive to get full read speeds

[vegetassj4]

Title says it all. I have the 4M2. If I do an extended write session which I assume fills any caching, the write speeds slow down - which I expect. However, the read speeds also are cut in half. Upon unmounting, then mounting the drive again, read speeds return to normal. I expect the difference with the writes considering the drives are QLC, but why with the reads? Anyone else notice this behavior?

Note: speeds were also verified looking at activity monitor.

Note2: Drive had been in sleep for >12hrs after the write session

OWC Express 4M2 w/ 4x Crucial P3 2TB in RAID 0

Speeds after an 300 GB write session



Speeds after unmount/mount

 

[Fishrrman]

This looks to be an "nvme-based" drive, is that correct?
They almost all seem to "run on the hot side".

I'm going to take A GUESS that during heavy reads/writes for extended periods of time, the drive is heating up and the drive's controller is "throttling back" the data speeds to [hopefully] reduce heat.

That's the "price of speed" it seems -- at least for nvme right now...

 

[vegetassj4]

This looks to be an "nvme-based" drive, is that correct?
They almost all seem to "run on the hot side".

I'm going to take A GUESS that during heavy reads/writes for extended periods of time, the drive is heating up and the drive's controller is "throttling back" the data speeds to [hopefully] reduce heat.

That's the "price of speed" it seems -- at least for nvme right now...

NVME, yes. But they get nowhere near close to temp to throttle (fan cooled, and don't run at max speed due to interfacing over thunderbolt: each drive can only max 700MB/s out of 3,000).

Also, this test was conducted over 12hrs after the extended write session, and therefore at their coolest operating temp.

A simple unmount/mount, with no other changes, resolved the issue.