With the speed at which HD music is moving, I was wondering if this was a "break through" or a "bust" (with a high ticket).
That's the crux of the issue John. Once it's "read until right", i.e. without errors it really doesn't matter if it's being read off of the HD or out of memory. When playing back, it's read from disk and stored in a memory buffer, albeit not the entire track. This can be changed in most players. I tested it in foobar, set to buffer 100 megs, playing tracks from my server and once the track is playing there is zero network traffic, so it's definately playing the entire track from memory. The only time it would be a real issue is if something else was hitting the disk hard but I suspect that for most audiophiles won't be doing much on their PC based music system while doing critical listening.
Devices like a Squeezebox have onboard memory, likely shared between the OS of the device and a buffer for the data, so they too are buffering part of the track in memory.
EAC reads all bits at least twice and will keep re-reading them until it gets two reads that are identical. It doesn't do error correction in the sense than an audio CDP does.
