1.4.7 had no issues with lag; but 1.5 has just overwhelming amounts of lag (even when you're not using a texture pack!)
Related issues
Comments
Are you referring to MC-8824 as well?
MC-11885
HD graphics are miserably slow
Resolved
Duplicate
0
Jason Wallace
(Unassigned)
Unconfirmed
Minecraft 1.5
Retrieved
Duplicate of MC-11875, please use the search function to see if your bug has already been submitted. Currently over 54% of tickets are being closed as duplicate.