LR6 OSX Adjustment brush slow lag

[KE_DP]

I'm experiencing long delays while trying to paint with the adjustment brush.  Even toggling the on/off brush adjustments pane is a bit slow to react.

I turned off the prefs/performance/graphics processor which helped maybe only incrementally.

5K iMac 3.3 GHz 32GB Ram

[johnrellis]

Which exact version of Macos?

[KE_DP]

OSX = 10.11.6 El Capitan

[johnrellis]

OSX = 10.11.6 El Capitan

LR pushes the limits on using the GPU, triggering bugs and performance issues in older GPU drivers.  Updating the graphics driver often solves display and performance issues.  Your version of Macos is relatively old, so it's entirely possible that updating the graphics driver will improve your performance.

Unfortunately, the only way to update the graphics driver on Macos is to update Macos itself (i.e. to 10.13.4). 

[KE_DP]

johnrellis  wrote

OSX = 10.11.6 El Capitan

LR pushes the limits on using the GPU, triggering bugs and performance issues in older GPU drivers.  Updating the graphics driver often solves display and performance issues.  Your version of Macos is relatively old, so it's entirely possible that updating the graphics driver will improve your performance.

Unfortunately, the only way to update the graphics driver on Macos is to update Macos itself (i.e. to 10.13.4). 

Thanks - I've been delaying updating due to potential software incompatibility, but it might be time to re-evaluate that position - at least for this machine and maybe keep an older OS on a bootable drive or 2nd machine for running the legacy programs.

[dj_paige]

johnrellis  wrote

OSX = 10.11.6 El Capitan

LR pushes the limits on using the GPU, triggering bugs and performance issues in older GPU drivers.  Updating the graphics driver often solves display and performance issues.  Your version of Macos is relatively old, so it's entirely possible that updating the graphics driver will improve your performance.

Unfortunately, the only way to update the graphics driver on Macos is to update Macos itself (i.e. to 10.13.4). 

There's just one problem with this. It is a true statement, that graphics drivers need to be updated — but graphics drivers are not the cause of this brush lag. The cause of brush lag is inherent in the design of Lightroom's non-destructive editing algorithms, and was present long before GPU acceleration was used in Lightroom.

[KE_DP]

dj_paige  wrote

There's just one problem with this. It is a true statement, that graphics drivers need to be updated — but graphics drivers are not the cause of this brush lag. The cause of brush lag is inherent in the design of Lightroom's non-destructive editing algorithms, and was present long before GPU acceleration was used in Lightroom.

Thanks for the insight - sounds like something we'll have to live with for now.  It does make me wonder if the behavior is the same in ACR?

[dj_paige]

ACR uses the same algorithms as Lightroom, so yes the same problem will appear. As I said, Photoshop and Photoshop Elements will handle brushing much faster.

[johnrellis]

The cause of brush lag is inherent in the design of Lightroom's non-destructive editing algorithms, and was present long before GPU acceleration was used in Lightroom.

Very much agreed. But others have reported that enabling a properly performing GPU lessens the brush lag.

[dj_paige]

  wrote

The cause of brush lag is inherent in the design of Lightroom's non-destructive editing algorithms, and was present long before GPU acceleration was used in Lightroom.

Very much agreed. But others have reported that enabling a properly performing GPU lessens the brush lag.

Then I'm surprised because enabling the GPU acceleration is supposed to slow down brush performance

[johnrellis]

Perhaps there's a difference in reports between those with very old GPU drivers that don't perform well on many operations and those with GPU drivers that perform well generally overall.   The former may be the source of reports that the brush lagginess improves with an updated driver. 

[dj_paige · Accepted solution]

Brushing causing slowness is a known problem in Lightroom, made worse on a 5K screen. Turning off the GPU should help some, but the problem is that your CPU doesn't have the power to re-render the image and re-draw the screen in any reasonable amount of time.

Some things you can try:

• Do the brushing in Photoshop or Photoshop Elements
• Do the brushing as the next-to-last editing step in Lightroom, and the last step would be to apply transforms and lens corrections if desired
• Get a much faster CPU

[JCCoulter]

I would say this is a huge problem. I am having the same issue on a system that has 16GB of RAM, a Gforce GTX 6GB video card and running an Intel I5 6600K 4 core CPU. What more should you need to run this program? Seriously? If you need more than that, LR is has serious issues.