Mac,
I'm not sure what your question is. Yes, before LBA the size of HDDs was really quite small! I remember my first PC in 1993 had a 100MB HDD. 1GB was server-size! 4GB was what we built RAID arrays on.
There have been a whole raft of "limits" on HDD sizes that have been overcome as the areal density just kept climbing.
But now we are into the TB range, 7.8GB is very small beer indeed - and LBA has rendered that particular limit nugatory.
This is a very useful piece on the 2TB limit:
Understanding the 2 TB Limit in Windows Storage - Ask the Core Team - Site Home - TechNet Blogs
SD