Here are examples of visual distortion created by bugs in graphics processors (GPUs) or in LR's use of GPUs. (Thanks to Google's image search.)
Many characteristics of these distortions ovlerap with those commonly associated with hardware faults (cards, readers, disks, memory). When troubleshooting distortions, it makes sense to first rule out the graphics processor and driver before considering hardware faults. It takes just a minute to disable the GPU, and a couple minutes to update the driver, whereas it can take hour or hours to rule out hardware faults. Even if we're 95% accurate at guessing a hardware fault, on average we'll save users time by first ruling out the graphics processor and driver.
Here are four pairs of photo, each pair sharing similar characteristics of distortion. The left photos were identified by you as hardware corruption; the right photos were confirmed by users to be GPU-caused:
Again, if we have just a 5% error rate at identifying hardware corruption, it makes sense to recommend disabling the GPU first. Consider the two strategies:
Strategy 1: Always troubleshoot hardware first, then disable the GPU if that doesn't work.
Strategy 2: Disable the GPU first, and if that doesn't work, troubleshoot hardware.
Assume troubleshooting hardware costs 60 minutes, and disabling the GPU costs 30 seconds. Further assume that 5% of images suspected to be hardware-caused are actually GPU-caused. Then the expected diagnosis time is: