So, I'm running on A Mac, and I want my FPS to increase, but recently, I tried to install Optifine for 1.4.5, but it didn't really work.(It crashes every time I load a level). But anyways, my FPS is usually 55-60 average. I use large GUI, far render distance, and fancy graphics. But today, I decided to see just how much my FPS could be. I turned on Tiny render distance, auto GUI, and fast graphics, and went into superflat. I pressed F3, and discovered my FPS was 500. :D So, here's what I want you to do for me: Do those steps that I mentioned, and when you see your FPS, please, come and post it in the comments section. I want to know if these steps help you. But anyways, thanks, and I'll see you later.
Edit: IF you look really close in the screenshot, you will see that my FPS is even higher. After I typed that post, I went in to Minecraft and took a screenshot, and my FPS SKYROCKETED to 729 FPS!