P: Noise reduction effect not displayed in Develop mode

When viewing an image in Develop Module it does not show any noise reduction you have done, in fact it seems to add noise. If viewed in library, then it shows, it’s correct, as does the export. In 1:1 you also see the noise reduction. Also, if viewing in Develop Module and you move a slider, for a split second it shows the correct image with noise reduction.

If you turn off the GPU then it acts as it should. I had a chat with Adobe and he saw the problem, but was at a loss. Then he said it was a driver issue. I am running a 5k 2017 iMac with Radeon 575, and also replicated the problem on two MacBook Pros. I called Apple, and they confirmed all drivers are up to date. The Adobe guy disappeared.

I am convinced this is an Adobe issue, as up until the updates a couple of weeks ago everything was smooth.

Just need clarification from Adobe that they are aware of the problem, but I have seen other users on other forums with the same issue, and the same response from Adobe support.

When editing higher ISO images with night skies or blacks it is critical to see the image as is in Develop Module.

Any updates on this issue? It's really starting to get under my skin, it's having a massive impact on slowing down my workflow by having to have GPU acceleration off

I can also confirm this is happening to my system as well after updating to Classic. I see grainy/noise in FIT view, and turning off using GPU resolved the issue, but this is unacceptable to me. Hopefully there will be a fix for this from Adobe, there's way to many different variables and system configurations in this thread for it to be graphics card issue/driver.

Thanks, I'm an experienced user and understand 1:1 previews. I usually don't bother to pre-render them. My standard previews are set to auto.

Rendering is happening just fine in the develop module, but fails in the library module. When I batch edited my photos, only the ones that I subsequently clicked individually in develop looked ok in library.  All the rest were heavily pixelated in the library, and remained so until I forced a build of 1:1 previews for all the photos. This is definitely a new bug that is unrelated to noise reduction. My post should not have been merged into this noise reduction thread.

Every time you do any edit on an image, all of the previews are invalidated, which is why it usually doesn't make sense to generate 1:1 previews as in many cases they will get invalidated anyway very quickly. 1:1 previews only make sense for very high volume shooters that as their first step select only those images that are correctly in focus.

For this case, check what is set for your standard preview size. Make sure it is big enough for your display. Usually the Auto setting works well. This is done in Catalog Settings -> File handling. It usually takes a few seconds to generate new previews after any change to the Develop settings and in the intervening time the preview in Library will look pixelated.

I very much wonder if the various merged threads are the same issue, but in response to one of them:

My edits in Photoshop are often not visible after I return to Lightroom. I haven't figured out any rhyme or reason to this. The Photoshop files are large (1-3 GB), but with Lightroom CC 2015 they updated soon after Photoshop was done writing the file. Now, not always.

I haven't figured out how to trigger an update — rebuilding previews seems to do nothing, as Lightroom seems to believe that preview is up to date, and I can't convince it otherwise. Even "touching" the file (changing the file modify date) does not seem to help. Then, sometimes after few minutes, the preview will update in Lightroom.

Lightroom CC Classic 7.0.1 + Mac OS Sierra 10.12.6.

In library module the preview of an image is not updated after returning from developing module. The only way to get it to update from pixelated/lined view is by either rebuilding the 1:1 preview (i built those on import already) or by zooming in. So i have to 'force' LR to do this by performing an action. Waiting for it to happen without doing anything is not working.
I developed an image with a (very) blue sky in develop module. If i go back to that image it takes a bit for the blue sky to 'smooth out' it looks lined and pixelated at first.

Mac 10.11.6
LR Classic 7.0
32gb ram/i7
for now gpu unticked because of the noise reduction bug (NVIDIA GeForce GTX 780M 4096 MB)

I'm having a very unusual problem with preview rendering in LR classic on Win 10. I'm working on a timelapse and edited one photo in the series. I then synced the edit to the rest of the ~300 photos. The sync was completed, but the previews were then rendered as very pixelated. The only way I can get them to render properly is to click on each photo one-by-one in the develop module and wait for a couple seconds, or build 1:1 previews. I have tried disabling GPU and restarting LR, as well as restarting my computer. I have left LR idle for a while, and my CPU is idle, so nothing is happening in the background. The pixelated images do get incorporated into my timelapse, when using a timelapse preset I downloaded and added into the slideshow module. However when I export individual photos they look fine. Here is an example of before and after building a 1:1 preview. Look at the sky to see what I'm talking about.

if I use smart previews it is ok (noise reduction is applied to the preview) if I use no smart previews then the problem exists. W10 GTX 980Ti latest nvidia drivers from 30/10/2017. in 1:1 noise reduction is ok at all times.

When I enter the develop module, the image starts to appear dim and with lots of noise, but after a few seconds, everything is "normal".
However, since the last update, the image never gets "normal" unless I disable the GPU. This had not happened before (last version).
This may be more or less noticeable, depending on the image, but in all of them, a grain increase occurs when the GPU is active.
I have already confirmed and my drivers are up to date.
I am using a GeForce GTX 960M (notebook) and RAW files are from a Canon 6D Mark II