Okay, so I'm having a problem with these amazing shaders.
After a while (20 minutes, maybe?), I get huge lag where my FPS drops to 0-3 and I have to restart Minecraft completely in order to make it playable again. Then it'll just happen again 20 minutes later.
16 GB Ram @ 1866 MHz
2x Nvidia GeForce GTX 570 in SLI, 4 GB dedicated memory in total.
Intel Core i5-2500K CPU overclocked to 3,9 GHz.
OCZ Agility3 SSD.
Running Win 7 Pro, 64-bit with 64-bit Java.
Optifine Multi-Core version. (Duh..)
I've tried with both the default and ultra configs, since my computer should be more than capable of handling the ultra shaders.
Minecraft doesn't run out of memory (uses at max 35%).
I've posted in the official mod thread, but I thought I'd ask here too.