I have a desktop PC with a Gigabyte motherboard type GA-P67A-UD4-B3 with a Kingston 64GB SSD as the boot drive C which has worked well without problems. I wanted to update drive C to provide more storage and I selected the Intel 240GB 520 series to use as a replacement.
My current drive C was copied to the new disk without any apparent problems, but my system would not boot from it. When the BIOS screen came up it had the top half as virtual lines and would never get pass this BIOS screen.
I copied my Kingston SSD drive C to a standard hard drive and tested that which worked fine.
I then re-copied my Kingston drive C to the new 520 SSD again just in case there was a problem with the copy, but it still would not boot using the new 520 series SSD.
So, I went out and purchased a new large Kingston SSD drive which worked without problems.
Conclusion is that my new 520 Series SSD cannot be used as a boot disk, well not with a Gigabyte motherboard anyway, but works perfectly as a non boot disk.
Am I missing something here or is there some issue using these SSD's with certain motherboards which certainly was not mentioned when I purchased it ?