Lightroom Classic: Poor video import performance & failures

  • 1
  • Problem
  • Updated 1 year ago
  • (Edited)
Performance importing medium to large video files into Lightroom Classic CC is extremely slow - less than half the speed of what can be done using the operating system.

It's also prone to failure on AVCHD files, which may be related.


Using the latest LR build on a reasonably recent i7 with plenty of memory and disk space:

1. Import in LR from card reader to spinning disk, 520mb .mov: 57 seconds

2.a. Copy same file from card to disk via operating system (Win10): 27 seconds
2.b. Import same file from disk via sync folder: 5 seconds

So, whatever LR is doing via method #1, it takes twice as long to accomplish the same task.

The difference in timing is even more stark if the target drive is solid state.

I notice that, while these tasks are running, the dynamiclinkmediaserver is intermittently taking up large amounts of memory (up to 1.6gig) and CPU (50%).


If the file is AVCHD (.mts), the import is prone to fail at random for some files. For example, if a card contains 12 files, maybe 5 will fail to import. But repeating the import will get 3 of the 5, and another repeat will get the remaining 2. There is no obvious pattern to this.

Edit: I spoke too soon: this may happen with mov as well:

As for AVCHD, simply repeating the import from the card usually works (though it may fail at random again).

Even if the file is imported, LR may think it can't be read:

However, there's actually nothing wrong with the file (it plays fine in VLC), so it seems that LR has just failed to read the cache.
Photo of Tom Fiddaman

Tom Fiddaman

  • 61 Posts
  • 16 Reply Likes
  • irritated

Posted 1 year ago

  • 1


  • 42 Posts
  • 19 Reply Likes
Hi Tom,
How frequently is it happening, the Failure part? Is it happening in every Lightroom session?
Try once killing the dynamiclinkmediaserver, and restarting Lightroom Classic.
Also which version of Lightroom Classic you are using?

Photo of Tom Fiddaman

Tom Fiddaman

  • 61 Posts
  • 16 Reply Likes
I'm not an the computer, so I can't tell you the #, but I keep LR Classic updated, so it's the latest build.

The failure is intermittent. Killing dynamiclinkmediaserver and restarting LR may help, but it's hard to tell because there seems to be some randomness (perhaps due to other system load or something like that). It still occurs even after a Win10 reboot though.
Photo of John R. Ellis

John R. Ellis, Champion

  • 5129 Posts
  • 1453 Reply Likes
"I keep LR Classic updated, so it's the latest build."

Unfortunately, Creative Cloud doesn't reliably keep LR updated to the latest version and often fools people into thinking they are "on the latest".  So when you get back to your computer, please copy and paste the first ten lines from Help > System Info here.
Photo of Tom Fiddaman

Tom Fiddaman

  • 61 Posts
  • 16 Reply Likes
Lightroom Classic version: 8.2 [ 1204643 ]
License: Creative Cloud
Language setting: en
Operating system: Windows 10 - Business Edition
Version: 10.0.17763
Application architecture: x64
System architecture: x64
Logical processor count: 8
Processor speed: 3.5 GHz
Built-in memory: 16179.5 MB
Real memory available to Lightroom: 16179.5 MB
Real memory used by Lightroom: 1309.5 MB (8.0%)
Virtual memory used by Lightroom: 1289.3 MB

I'm sure this has been going on for some time; it's not new since my last update.
Photo of Tom Fiddaman

Tom Fiddaman

  • 61 Posts
  • 16 Reply Likes
The performance issue is 100% consistent, I think. LR is always much slower than the OS.
Photo of Tom Fiddaman

Tom Fiddaman

  • 61 Posts
  • 16 Reply Likes
BTW the failure issue has other open tickets:
The general poor performance didn't have one, so I started this.

There are a zillion unresolved forum threads (at Adobe and elsewhere) about the failure problem: