I'm getting really bad FPS and lag spikes recently, but never really had such a problem as this under 1.2.5 and tekkit. I'm using a 64x texture pack, and optifine, and get 2-10 FPS. If I press escape to the menu, it shoots up to 30+ and the chunk loading is a lot faster. If I revert to default texture pack, my FPS is 60-100, but still with random spikes down to 10 FPS. My ForgeModLoader-cient log is filling up with the same 3 lines 2012-12-20 22:59:29 [INFO] [STDOUT] ########## GL ERROR ########## 2012-12-20 22:59:29 [INFO] [STDOUT] @ Pre render 2012-12-20 22:59:29 [INFO] [STDOUT] 1281: Invalid value I've a 1.4meg log file from my last 15 minute testing with stuff playthrough. This is just on an undeveloped world. Now, I hope to god that my graphics card is not on it's way out. I have a feeling it's more to do with the Minecraft update from 1.2.5 has made things worse on my system. (I've gone from 1.2.5 to 1.4.x) Allocated memory is 768meg, if I go higher or lower, FTB minecraft always crashes with out of memory error. My memory usage is always at an alarming 50-70% with nothing going on in the world. Just wondering if anyone has any tips on trying to get a more stable FPS without forking out for a better computer (it's a dual-core, 2gig memory, 512mb gfx and can run games like Skyrim/WoW/EVE online on ultra settings no problems) or downgrading my texture pack. I've always had low FPS in minecraft, but nothing as bad as this. What's odd is that it's only got this bad very recently. A few weeks ago I visited 10 mystcraft ages one after the other, exploring them all with no issues). Nothing has changed on my system since then. Other gaming is fine.