Lightroom 2015 CC slow on powerful PC but fast on Macbook

[AlexClaude]

Please someone tell me what I'm doing wrong or, Adobe, please acknowledge some of your product just suck under windows environnement.

I have two machines (see specs bellow): A powerful PC (built last year) and a Macbook Pro Retina (bought in 2012).

On both machine, I have Lightroom CC 2015.

Lightroom runs as a charm on my Macbook Pro, but slow on my PC... WHY?!?!

SPECS:

PC:

- Flash drives: 2 x Samsung 850 PRO 1TB SATA 6.0 SSD       

- CPU: 2 x Intel Xeon E5-2630 v2 2.6GHz LGA2011 6-Core 15MB CPU

- 64go of memory: 2 x Crucial 32GB ( 2 x 16GB ) DDR3 Registered Memory

- Cooling system: 2 x Corsair Hydro Series H80i Intel/AMD High Performance Liquid CPU Cooler

- Graphic card: 1 x PNY NVIDIA Quadro K4200 4GB DDR5 Video Card

- OS: Windows 10 (had windows 7 and had same problem)

Macbook Pro Retina:

- CPU: 2,7 GHz Intel Core i7

- 16 Go of memory 1600 MHz DDR3

- Graphic card: NVIDIA GeForce GT 650M 1024 Mo

- Flash drives: 750gb flash memory drive

- OS: El Capitan 10.11.4

[SteveD333]

Assuming all other things are equal, and you don't mind losing any preferences you may have changed, try starting

Lightroom by holding down Shift+Alt on the keyboard first.  That way Lightroom starts with all its default settings/preferences.  As an aside, I too have a reasonably powerful PC and I have no problems with

Lightroom at all, so something is definitely not right with your setup.

[Just Shoot Me]

I think it is the Xeon CPU's. But you might try turning off the User Graphics processor in the performance tab of the LR preferences and see if that helps.

Look here.

https://www.pugetsystems.com/labs/articles/Adobe-Lightroom-CC-6-Multi-Core-Performance-649/

[Jao vdL · Accepted solution]

AlexClaudePhotography wrote:

Please someone tell me what I'm doing wrong or, Adobe, please acknowledge some of your product just suck under windows environnement.

For every person complaining that Lightroom is much slower on their windows machine you can find a person complaining that Lightroom is much slower on their Mac than on their PC. This is really hard to figure out. As said, sometimes having the graphics acceleration turned on actually slows down Lightroom but in the last versions of Lightroom this has really improved to the point I now have it turned on on my machines and it certainly feels faster than having it turned off. I have an older retina MBP just like you and it's quite amazing how well it holds up even against many tricked out more modern machines. That said that monster machine should be much faster in actual operation. It could be that running Lightroom of the 12-core CPU might actually be faster than using the GPU. Whether it is windows or Mac OS should really make very little difference. If you have persistent slowness, there are a few things to try to test. One is to reset your Lightroom preferences. People have reported slowdowns on machines that have been updated many times to newer Lightroom versions where sometimes some strange corruption of the preferences files can lead to very slow Lightroom behavior. This is done by restarting Lightroom and holding the shift and alt keys. You should get a dialog such as this one: http://lightroomkillertips.com/something-acting-weird-try-resetting-lightroom-ccs-preferences/ 

Other causes of slow Lightroom behavior specific to your case can be an overactive antivirus software that rescans your catalog file every time you do an edit, having face recognition running always on Lightroom, building 1:1 previews in the background, automatic .xmp writing, and several other causes. It might make sense to investigate some of these.

[paland89]

Holy sh***!

Restarting LR using ALT+SHIFT really really worked. Had the same win/mac problem. Wish I knew this a few months ago!

Thanks!

[AlexClaude]

Thanks everyone for you answers.

I did try to hold ALT+SHIFT  while starting Lightroom, ans it seems to have worked!

Thanks!