External Hard Drive incredibly slow after High Sierra

It's definitely a bug with the custom thumbnails. I even tried cropping the photo (which is something I never used to need to do) and it still appeared square and stretched. When I made my initial bug report, I included both issues (the thumbnail issue and the slow loading time) and know others here mentioned both in their reports as well. It's one of those things that should be an incredibly easy fix.

I wrote here some weeks ago that i was experiencing the same problem. Then I updated OSX and I wrote that the problem was fixed. Well, it's not fixed at all. The mac returned to be incredibly slow on external HDs. And it's not just that icons loading... I can't work on external HD files. I must copy them on my internal HD SSD otherwise it's impossible to work! A Photoshop file (300MB) takes 2 minutes to be opened from the external HD while once copied on the internal HD it takes less than 8 seconds. Very disappointing.

Same here...-- I still have the same issue, and any Apple help I call, I get the reply that all is good on their side, it is my external drives, it is my installation, it is my apps I installed... has NOTHING do to with OS X or apple itself. EXTREMELY FRUSTRATING!

I have several RAIDS, and usually copying a file of a few GB takes seconds,... now it is minutes! Working in Lightroom is a pain now, as Lightroom can needs the data when accessing external Media... it is so so slow, you just sit here and do not know what to do!!!!!

Like everyone on this thread I’m experiencing poor external hard drive performance with High Sierra.

I’m also stuck with a hardware issue. Today’s fast SSD use the M2 nvme interface but for some unexplained reason It seams that there is no way to get an M2 to thunderbolt 3 connector.

Anyone in this forum knows why there is no connector available on the market to connect an SSD to a Mac in a performant way?

An M2 SSD has over 30Gbits throughput and thunderbolt 3 is capable on the paper of 40Gbits.

Best connector I can find is using USB-C at 10Gbits/s with is only 30% of the SSD performance.

There is a sonet fusion drive at a very expensive price but it’s never available.

It’s so slow to work on external drive that only way is to copy all files on internal drive, work on it and then copy everything back to the external hard drive.

It’s hours of lost time every single day.

Now that the iMac pro is out, it’s very hard to understand why Apple doesn’t care about this problem.

Well, for me things went from bad to worse.

Now it's using ungodly amounts of resources and nothing I do works to terminate the process, it just starts again.

Yes I'm still having the problem. The difference compared to the previous system version, is that it happens only once (at least for the icon problem) and when the icons are loaded, it doesn't happen anymore. Yet... if you're like me, working 100% of the time , every day, with hundreds of files per day, many softwares, then sometimes the mac slows down and you have to optimise it (cleaning caches, repair permission etc...). I noticed that if you do it... then the problem occurs again. In that case you'll have to wait (for me it's hours) and then until you won't optimise your mac again, the problem remains fixed.

Said that... I'm still having problem in terms of speed when I load files from external HDs (SSD or HHD) using both Thunderbolt 2 or USB 3.

I recently upgraded from Sierra to High Sierra straight through to 10.13.3.

I had an external hard drive with folders containing large numbers of large video files, many bearing custom icons. The external drive was on a Mac OS Extended (Journaled) / HFS+ file system.

Though it was suggested that the more recent updates fixed some or all of these problems, I still experienced both:

(1) "Verifying file..." issue upon attempting to open any of these files (reddit link)

(2) Finder freezing with kernel_task consuming heavy resources, when attempting to browse any of these video folders, but not in other folders. Incidentally, the system was otherwise fairly usable with Finder frozen.

I tried the following:

- Reset NVRAM (why I thought this would do anything, don't ask me)

- Booting into safe mode

- Using Disk Utility's 'First Aid' function on the drive.

- Deleting ~/Library/Preferences/com.apple.finder.plist

- Adding the external drive to the Privacy section to exclude it from search indexing

- Removed Quarantine attribute from the large video folders using: xattr -d -r com.apple.quarantine <folder>

- Disabled Quarantine using: defaults write com.apple.LaunchServices LSQuarantine -bool NO

I think the steps were done in roughly this order, but my memory is blurry.

Currently, both issues are resolved and my custom icons are intact.

Apple do not recommend APFS for HDD disks, for this very reason.

I really do not think it is the HDD failing.

Don't assume. Determine. Until you do, we're both guessing.

Until you do something you're not helping fix whatever is wrong with your Mac. It's not reasonable to expect others to help you either.

It shouldn't take minutes. 50 icons should take a few seconds at most. I don't know if the fact they're videos has any bearing on that though.

I understand. Having one would enable you to explore some troubleshooting options though.