Pill shaped progress bar when returning from sleep mode

When I boot my iMac from sleep mode, it takes forever to initially load. When the screen turns on, this pill shaped loader/progress bar appears over the login screen with everything inactive until it completes. When it completes, I am able to successfully login. I have also gotten the grey screen of death twice now, assuming it is related.

I wiped the computer and reinstalled the OS last night, and already seeing the problem persist. Anyone else experienceing this issue or know of a solution?

Thanks.