CF Card transfer hangs on Mac

Wondering if anyone else has this problem and looking for a solution.

I shoot a ton of foot race events that are high volume. I also manage teams of photographers and handle file management for them as well. After a race, I may have 20 CF cards with about 8000 photos on each. (Small JPG mainly, 2500 long end), makes about one meg per photo. So the problem I am having is transferring all of the cards to my computer.

I use a RMBP i7 quad late 2013, 16 gigs ram, 512 SSD.

Transcend USB3 reader.

Cards are a mix of brands but either 8 gig or 16 gig cards.

No issues with Nikon files or SD card files.

CF Cards - When transferring Canon files, If I grab the entire folder or really anything more than 500 files, it tends to hang for a long time, then will process 50-60, then hang again and will take more than 15 minutes to download a card. Sometimes it will continue to hang and I have to cancel it. Nikons folder structure are broken up into 999 files so that may be why I am not having issues with Nikon files.

Finder isn't locked out as I can do other tasks. I have been told it could be a finder issue with copying. Been suggested to use PhotoMechanic to bypass the finder. Which to me is a bandaid, not a fix.

After files have downloaded, I can transfer the entire batch 30000 photos or more to a USB3 drive without issue. Just seems to be from the reader using CF cards.

Any ideas what could be going on? Not entirely convinced its a bad reader as the Nikon files work fine.

I have seen other posts online about similar issues but no real solutions yet.

Thanks for any help you can provide.

A couple of questions:
(1) how fast would a similar stash of photos upload from your Nikon cameras?
(2) Have you tried going straight from your camera to the computer? That's one thing you could test to see if it hangs there. Granted, it'll probably default to USB 2.0 speeds, but that's at least one way to get a 'base line' as to what's going on.

Very odd indeed. Definitely sounds like some kind of a 'buffer' issue. Almost as if your USB 3.0 is defaulting to 2.0 speeds...because 8000 photos at 1mb a piece taking 15 minutes sounds like 2.0 speeds. But I have no idea why it would do it for Canon cards and not Nikon.

BeritOlam wrote in post #17066651
A couple of questions:
(1) how fast would a similar stash of photos upload from your Nikon cameras?
(2) Have you tried going straight from your camera to the computer? That's one thing you could test to see if it hangs there. Granted, it'll probably default to USB 2.0 speeds, but that's at least one way to get a 'base line' as to what's going on.

Very odd indeed. Definitely sounds like some kind of a 'buffer' issue. Almost as if your USB 3.0 is defaulting to 2.0 speeds...because 8000 photos at 1mb a piece taking 15 minutes sounds like 2.0 speeds. But I have no idea why it would do it for Canon cards and not Nikon.

Not my cameras, just the cards shot on those cameras. I dont have Nikon equipment to test. The nikon files transfers without issue though.

Havent tried the Camera direct to computer. That could make a good test. Thanks for that. Might just buy another reader and test there as well. Not 100% convinced its an OS or finder issue. I just transferred the entire batch of 40k photos at 50.2 gigs to my backup thunderbolt drive and it took 8 minutes.