Lightroom 5.7.1 on Dell 9550 with external Dell UltraSharp UP3216Q 4K display

Hello,

I have recently purchased the following setup for image processing which I thought would be rather high-end:

a) Dell XPS 15 9550 Notebook with 16GB RAM, 500GB internal SSD, and internal 4K display
b) Dell UP3216Q UltraSharp 32" 4K calibrated external monitor

I am using Lightroom 5.7.1 on my internal display to my satisfaction; which leads me to the assumption that the setup is in principle perfectly capable of handling Lightroom 5.7.1. with a 4K resolution.

However, once I connect my external display and move my Lightroom 5.7.1. window onto the external display, Lightroom instantly gets unusably slow. Resizing/cropping takes approx. 1 second to follow my mouse movements, using any sliders also has a lag of about 1 second, and so on.

I have the external monitor connected via an USB3.0-to-DisplayPort adaptor, could this be a problem?

Why is my system capable of handling 4K Lightroom on an internal display but not on an external display? What could be the cause of this problem and what could be possible solutions?

Thanks and best regards,

Matthias Höller

 

I suspect the new Dell Thunderbolt dock with Displayport/MiniDisplayport connecions would take care of the problem.

 

I assume you are referring to the Dell TB15 and/or the Dell WD15? Can you elaborate a bit more why you think it will solve the problem (just to educate me)?

Thanks in advance,
Matthias

 

This is most definitely the problem. USB 3.0 is convenient, but is a pretty poor interface for external graphics adapters (which is essentially what the USB 3.0-to-DisplayPort adapter is). The problem is exacerbated by the fact that you're trying to drive 4K resolutions through that adapter, which puts an even higher strain on the already-bottlenecked USB 3.0 interface.

Your best bet is to go directly through your Thunderbolt 3 (USB Type-C) port, using something like this. There are other models out there. But I did the research, and this one specifically supports 4K @ 60Hz refresh rates. This should completely eliminate any lag on your external monitor.
http://www.amazon.com/DisplayPort-V...1&keywords=usb+type+c+to+display+port+4k+60hz

 

Kent gives an excellent explanation - I deal with 4K video all the time both 30p and 60p and USB 3.0 will just not hack it.

 

I have to apologize. My initial description contained an error. My adaptor is actually an USB-C type similar to the one you posted.
I did not check on specific technical details before buying it. I can, however, select 4K resolution with 60Hz refresh rate in the intel driver configuration menu for my external display with this adapter. I suppose that means that my adaptor does support this resolution/rate combo, right?

What else could be the problem?

Thanks and best,
Matthias

 

What is the exact model you bought?

And no, you can't always just rely on whatever the Intel drivers / resolution settings say. The only reliable source of info on what kind of signal the monitor is receiving is through the monitor status info itself.

Sent from my XT1575 using Tapatalk

 

Hi,

thanks for the reply.
The exact model I bought is the following: http://www.ebay.de/itm/291608526807
(I hope ebay links are allowed on this site)
The screen frame rate / repeat frequency definitely is NOT the problem here, the effects I am experiencing in Lightroom (as described above) are not caused by the frame rate. So I have no reason to doubt that the frame rate is indeed 60 Hz as told by the driver.

Does anybody have any idea what else I could try to speed up lightroom on my external 4K monitor?

Thanks in advance,
Matthias