When you place a block, it will be invisible for a short time before appearing. When you destroy a block, it will appear to still be there for a short time.
Linked issues
duplicates 1
Attachments
Comments 2
Dupe of MC-62166
MC-62389
Block placing/destroying lag
Resolved
Duplicate
0
Michael DiFranco
(Unassigned)
Unconfirmed
Minecraft 14w29b
Retrieved
Have the same experience on Fedora 20, Java 1.7.0_60 OpenJDK
Attached a screenshot.