How important is 'scan whole files' when doing a full system scan ?

[REDACTED]

Ive just done a scan of my system that turned up c. 300 infections, most of them malicious email attachments in spam mail.

I did this scan with PUP checked, but 'scan whole files' unchecked. Its got me wandering how important it is to scan the whole files, the main reason i guess you wouldn't do this is for speed and at the moment with whole files unchecked it still took c.8 hours to complete (there is c.500gb to scan, not sure if thats fast, slow or normal)

How much longer on average does a whole file scan take, and how likely is it to find stuff missed by a non whole file scan ?

[tumic]

In general this option should be used only when scanning some suspicious location
or something strange is going on. The scan takes significantly longer with it turned on
and in most cases it will not give "better" results.