I used video memory stress test v1.7.116. Below are the results.
Changing video mode to 640x480x16...OK
[12/9/2012 5:25:09 PM] Test started for "Primary Display Driver
(AMD Radeon(TM) HD 6520G)"...
Trying 16bpp RGB:565 mode...OK
Trying 16bpp RGB:555 mode...OK
Trying 16bpp BGR:565 mode...NOT SUPPORTED (Code: 80004001)
Trying 32bpp RGB:888 mode...OK
Trying 32bpp BGR:888 mode...NOT SUPPORTED (Code: 80004001)
[12/9/2012 6:43:40 PM] Pass completed (0 errors found).
What do these mean?