alot of Chunk updates when walking around may reduce FPS

i have recently been playing on the latest snapshot with a few of my friends the server has been crashing alot we found that resting the world didn't help we also had 4GB of ram so we knew that ram wasn't a issue

when i was looking in F3 earlier today i noticed when i walked a few blocks that around 100-200 chunk updates would happen i wonder if this may of been the reason because if 5-10 people was to be updating 100-200 chunks in such a short amount of time this would be updating so many chunks it may cause the server to lag i also was testing on 1.7 and the chunk updates was not as high as the latest snapshot i don't know if the chunk updates are suppose to be so high but i don't know if this is reducing players fps

i did check to see if there were any duplicates but i saw none about the recent pre release but i did see some about snapshot 14w28b but apparently this was fixed but i still get alot of chunk updates sorry if this is a duplicate and if this isn't a bug.