Originally Posted by kernalk
The main thing I see is a dramatic amount of stuttering when I turn in any direction. Standing still everything's groovy but when I turn at all I would estimate that the real frame rate is about 3fps.
Normally it's not too bad but it causes significant issues placing blocks and if I'm attacked by a mob from either side or behind I'm often toast
I have the exact same issue. It seems to be mostly limited to new chunks the server hasn't generated yet, but I've also experienced this in the overworld inside my garden from time to time. I normally get a smooth 30 or 60 fps myself, depending on what biomes I can see, but lately I've been getting lagspikes that drop my fps down to 4 sometimes. It's already killed me once and cost me several iron tools, a few stacks of glowstone dust, and almost a stack of nether quartz. Good thing I wasn't carrying diamonds.
Originally Posted by pvyParts
out of curiosity whats your rig like. there are a few things to check, update java and check that your display drivers are up to date.
My drivers and Java are up to date.
CPU: AMD Athlon II (quad-core)
RAM: 4 GB
OS: Windows 8 Professional
Video: Nvidia GeForce GT 430
I haven't tried it in single-player or any other servers yet, so I don't know how isolated this issue is.