I have a pretty good desktop, and it's never really had issues running anything, especially minecraft.
But for the past week or so, I've been having issues with minecraft running extremely slow.
I have tried everything, including completely deleting everything in my .minecraft folder, trying default texture pack, putting graphics on fast, render distance on tiny, everything! But none of it works.
I haven't been running any mods or anything lately, the only thing i have been messing with are texture packs, and none that require anything special, just basic 16x16.
Basically, when i log in and start it up, everything runs smoothly up until i enter a world or server. Then the game starts lagging uncontrollably to the point where i can't play it at all. I can't even move, because it takes a couple minutes just to do so.
Does anyone know how i can fix this, and does anyone know the cause of it? I will give you whatever information you would need to know, if you need it.
So I realize this is an old topic, but i ran into the same issue today and it took me forever to figure out why the Sphax texture pack was running so slow, when it had been working fine beforehand....
The long story short: I am using MCPatcher, and I uninstalled a Mod that wasn't working properly... and upon doing so I also (by accident) uninstalled the "Extended HD" mod that comes defualt with MCPatcher. So...the next time I log into minecraft after doing this the game is EXTREMELY laggy.
The FIX: After hours of tweaking and research, I simply re-patched the "Extended HD' mod that came with MCPatcher. And now the Sphax texture pack (128) works like a charm. Accidently un-patching that mod seems to have been my issue. Re-patching it fixed me.
So, I wanted to post my solution in case anyone else runs into the same thing... maybe google will lead them here and they can try this.