Lightroom 6 /Lightrooom CC. GPU Acceleration: the good, the bad and the ugly.

The title says it all really: it’s got its good points, but at this stage, from what can be seen in the Adobe forums, there are far more problems than benefits for most users who have tried it, myself included.

Firstly however, why did Adobe implement it? The main reason is the advent of 4K and 5K monitors. These monitors run at 8MP and 15MP respectively: that’s a lot of data to process. Moving sliders around without GPU acceleration would give around a choppy, unresponsive 5fps. With GPU acceleration the sliders operate at a silky smooth 60fps (on a high end graphics card).

So there are massive gains to be had and in theory a much more pleasant user interface.

So all things should be great now, right?

Unfortunately not. The develop is the only module that currently has some GPU acceleration: all the other functions and modules, such as Library, Export, and Quick Develop, do not use the GPU acceleration.

Some? Yep…that’s right, some. So far this includes the basic and tone panel, panning and zooming, crop and straighten, lens corrections, gradients, and radial filter.

All these controls, even on a 3 year old GeForce GT 620 with only 1GB of DDR3 RAM, show a massive improvement in useability. The controls are smooth and responsive, pretty much instantaneous.  That’s the good part.

The bad part is that there is small delay in getting the image into the GPU in the first instance, so there is some lag in switching between images, which isn’t great. Not that it was great in the first place either. Switching between images was my biggest bugbear with LR. It’s always been slow compared with other RAW viewers. I’m almost at a point now where I’m going to have to cull images outside of LR and then bring them in, but I really don’t want to be doing that.

So what’s the ugly part? Well for me, and a lot of others, it’s that the controls, such as local brush adjustments and spot clone/heal, don’t have GPU acceleration,  at least not yet anyway. For me this is like buying a Ferrari and not getting given the wheels. A pretty pointless exercise.

It’s ugly not because it’s not any faster, but because it’s actually slower. Suddenly performing any changes using these tools becomes a clunky, slow process. Which is absolutely ridiculous, particularly given that the gradient tool (which is now super smooth) now has a brush function that is unuseable. Cue a Captain Picard facepalm.

And the really ugly? There have been a number of cases where users have reported a blue screen with a cross through it where, in theory, a graphics card that should be compatible, isn’t. So they can’t even get to try GPU support.

At the moment my GPU is disabled and I can see it staying this way for a period of time: Adobe’s bug list for LR6 seems to be growing at an exponential rate. I can put up with some slower sliders for the sake of smooth and functional brushes.

I’m just glad I didn’t pay for a new super-duper graphics card, because apparently it’s just as bad on some high end cards……….

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