I have collected about a dozen single bit (corrected) errors in my home cloud, and seen 2 uncorrectable errors. I also have come across about a dozen 'bad' sticks of ram which show errors in memtest86, about half of which only have 1 bad row, and 2 of which only show errors after multiple passes which I assume is thermal based.

I do however build all of my computers from pieces from the recycling, so the statistics may be a bit off of the norm...