OWC Envoy Express is kneecapping my Acasis drive

[jim0266]

Setting up and testing my new (refurbed) base Mac Mini M2 Pro I ran across a head scratcher that appears to point to the OWC enclosure as the culprit.

I have two Acasis TBU405 enclosures each with a 2TB Samsung 970 EVO. The OWC has a Silicon Power 2TB. My plan was to use the SP NVME in the OWC as my home/user folder. One of the Samsungs will be my Final Cut Pro work disk and the other will house my photo and video archives.

Moving the home directory to the OWC worked flawlessly. Before calling it a night I decided to test the speeds of the drives with Black Magic. The one 970 was as expected, 2800 write and 2730 read. The other drive was below 1000 for both read and write. Bum enclosure? Bum drive?

If I only ran one Acasis/Samsung drive at a time with the OWC also plugged in each had full speed.

No matter which drive I selected the first one was full speed and the second one plugged in fell back to below 1000. Which of the four ports I selected did not matter.

I rebooted the computer to disconnect the OWC drive and boot into another user account. You cannot unmount a drive that has been set at the home folder. Both Samsung drives reported the same 2800 write and 2730 read via Black Magic!

Reboot with OWC running and it's back to slow speed for one of the Acasis/Samsung drives if both are mounted.

If I unmount the fast Acasis/Samsung drive the remaining Acasis/Samsung still runs at the slow speeds. If I unmount/unplug the slow drive and plug it back in alone it's back to the full 2800 write and 2730 read speeds.

Looks like the OWC is going back unless someone has any ideas I can try. I purchased the OWC in case the Acasis enclosures were duds. They were only $10 more than the OWC when purchased off the Acasis site with coupons.

 

[satinsilverem2]

The Envoy Express is only x2 not the full x4 that thunderbolt 3/4 supports. I have a Sabrent Rocket in mine and the drive is rated for 4000+MB/s but I only get 1200-1400MB/s. This is a known limitation that OWC discloses on their website.

 

[jim0266]

The Envoy Express is only x2 not the full x4 that thunderbolt 3/4 supports. I have a Sabrent Rocket in mine and the drive is rated for 4000+MB/s but I only get 1200-1400MB/s. This is a known limitation that OWC discloses on their website.

I think you misread my post. My issue is not with the speed of the Envoy Express. It's getting the advertised 1200-1400MB/s.The OWC drives is causing one of the Acasis/Samsung equipped drives to go from 2800 MB/s write and 2730 MB/s read speeds to about 960 MB/s.

 

[satinsilverem2]

I think you misread my post. My issue is not with the speed of the Envoy Express. It's getting the advertised 1200-1400MB/s.The OWC drives is causing one of the Acasis/Samsung equipped drives to go from 2800 MB/s write and 2730 MB/s read speeds to about 960 MB/s.

I did indeed misread, I apologize for that. I would say that is has to do with bus sharing between ports but I believe that on AS Macs each TB port has its own bus. Also as there's no SMC on M1/M2 machines im at a loss.

 

[jim0266]

Sharing a video I made for OWC showing the problem in case this helps someone else.

 

[Fishrrman]

Some problems don't have "solutions".
Maybe it's time to replace the OWC enclosure with a different one.

 

[jim0266]

Some problems don't have "solutions".
Maybe it's time to replace the OWC enclosure with a different one.

Yep. It's going back once other Acasis enclosure arrives.

 

[jim0266]

Sorry OWC for pointing the finger at you as you appear not to be the fault. I think this is an Apple hardware/firmware issue. My new Acasis drive arrived. Same problem. When three TB drives are attached, adding a third drive reduces the speed of the third drive.

 

[chrfr]

Is each disk in its own port directly on the mini itself?

 

[jim0266]

Is each disk in its own port directly on the mini itself?

Correct. I ran the test below today with all three of the TBU405 enclosures, switching the drives up between reboots.
The Silicon Power 2TB is almost as fast as the Samsungs, at least as measured by Black Magic. I switched the drives up between reboots looking for a pattern, except for sessions 5 and 6 below. I rebooted that time with the drives in the same location. This time the slow drives switched from the 1 slot with the Silicon Power to one the Samsungs with the 970.

All three drives were plugged in at the computer's start.

1. Slow (970 drive 1)
2. Fast (970 drive 2)
3. Fast (SP)
4. Open


1. Open
2. Fast (970 drive 2)
3. Slow (SP)
4. Fast (970 drive 1)


1. Slow (970 drive 2)
2. Open
3. Fast (970 drive 1)
4. Fast (SP)


1. Fast (SP)
2. Slow (970 drive 1)
3. Open
4. Fast (970 drive 2)


-----------

1. Slow (SP)
2. Fast (970 drive 2)
3. Open
4. Fast (970 drive 1)


Reboot computer, same order as above.
1. Fast (SP)
2. Slow (970 drive 2)
3. Open
4. Fast (970 drive 1)

--------------------

 

[jim0266]

Talked with an Apple senior engineer (this guy was the first person I spoke with who actually heard of Black Magic Speed Test), or he was at least several levels up from who answers the AskApple number. He laid the blame on the TB ports sharing sharing channels. 1&2 sharing a channel and then 3&4. It still doesn't make sense why I can get a slow drive on port 4 when nothing is plugged into port 3 and both drives on ports 1&2 are getting full speed.

 

[chrfr]

Talked with an Apple senior engineer (this guy was the first person I spoke with who actually heard of Black Magic Speed Test), or he was at least several levels up from who answers the AskApple number. He laid the blame on the TB ports sharing sharing channels. 1&2 sharing a channel and then 3&4. It still doesn't make sense why I can get a slow drive on port 4 when nothing is plugged into port 3 and both drives on ports 1&2 are getting full speed.

But the senior engineer would be wrong. Each port is on its own bus; this is a key improvement over Apple’s Intel based Mac architecture.

 

[jim0266]

But the senior engineer would be wrong. Each port is on its own bus; this is a key improvement over Apple’s Intel based Mac architecture.

Thanks, I thought they had their own bus. I took my three enclosures to an Apple store and plugged them into a Mac Studio. Same behavior. Testing with a 6GB file copying back and forth you could tell that one drive of the three drives was randomly slow by timing it.