Photo import transfer speed is slow (50 MB/s)

[info2x]

Not sure what's going on here.  I've never found LrC to be super fast with how it handles importing photos but it's gotten a lot worse lately.  While playing around with an import tonight I was getting 50 MB/s for the transfer speed.  Taking the same folders and importing them with windows explorer: >600 MB/s. 

I can't seem to find what I've done for this to happen.

CF Express cards via thunderbolt card reader, Windows 10, LrC 14.3. Here's the kicker. I'm not sure this is just a LrC issue. I tried using Photo Mechanic and am getting similar speeds.

Thoughts?

[dj_paige]

Perhaps your card reader is malfunctioning? Perhaps the camera card is malfunctioning?

[info2x]

I've tried with different cards and readers.  Also wouldn't explain why explorer is still quick.

[JohanElzenga]

How exactly did you measure this? Importing images in Lightroom Classic is more than just copying them. Lightroom Classic will also generate previews (unless you use 'Embedded & sidecar') and you may have inadvertently checked the option to make a secondary copy as well.

[info2x]

I was monitoring the speed via task manager looking at both the disk the images were being written to (M.2 drive) and the source CF Express Card(s).

I typically do minimal previews.  I also don't do seconday copies and verified it was off.

I'm not expecting to have the same performance as explorer because LrC is doing more than just a straight file copy but a more than 10x reduction in performance is not normal.  I actually got impatient and did a clean windows install with LrC and my speed jumped back up to normal for LrC.  PM is still terribly slow.

[Ian Lyons]

@info2x  wrote:  "tried using Photo Mechanic and am getting similar speeds."

If importing via Explorer is fast, but LrC and Photo Mechanic are slow, then @JohanElzenga comment re previews is worth following up.

Personally, when using faster SD and CF Express cards I find it quicker to copy files from the card to disk using macOS Finder, then use LrC's 'Add'. 

[info2x]

I like doing the import natively mainly because of the ability to do incremental imports and have it rename files if a file name is already used.  I'm willing to sacrafice some performance to achieve this but >10x is a no go.