The two most common reasons for big discrepancies between Library and Develop are 1) the use of the graphics processor and 2) an incompatible display profile. You've already disabled the graphics processor, so try troubleshooting the display profile: How do I change my monitor profile to check whether it’s corrupted?. (Make sure the graphics processor is disabled when you do this.) The artifacts in your sample images don't strongly suggest an incompatible profile, but it's easy to check and you should rule it out.
thanks for that tip, so i tried that monitor calibration but did not help, same problem persists.
as far as i can tell this only happens in lightroom.
when i use other imaging apps i never see this issue
for exam ple, capture one pro, no problem, lyn, works fine, adobe photoshop also fine.
I've had this problem since lightroom 4 i think and since then i've had different computers, so i'm pretty sure its not my hardware at this point I blame it on poor software coding. it has to be software.
at the school where I work at, I see exact same issue also, a bunch of imacs 21 inch and in LIB mode i see the odd pixelation in dark areas of the image. the more black in image the more prevalent it is.
I've seen this happen in windows and mac computers.
perhaps there is no solution until adobe fixes it along with the many other bugs i come across.
It's very curious -- I haven't seen anyone else with these particular symptoms over the past many years, so it's likely not striking very many people (which could make it harder to troubleshoot). If you upload a sample pic with the problem to Dropbox (or similar) and post the link here, then others can see if the problem occurs on their configurations, and then we can file a bug report if necessary.