How to reduce minecraft lag?

I have a computer that is not so great, and the lag I get on Minecraft is very annoying.
The lag is not so bad on vanilla, i average about 9 fps, but as soon as I add in a mod, my fps decreases to 2.
I have downloaded Forge 1.7.2, and I have downloaded the mod optifine, but when I have optifine running my minecraft doesn't even open. It opens with other mods just not optifine, so I was wondering if there was a way to decrease lag without having optifine running. I have decreased all the settings but the lag I get on mods is unbearable.
Any suggestions?
:)

Guest

Check OUT THIS TUTORIAL.

Martha

If you're willing to turn your options down, you don't care about graphics, right?

This texture pack is hideous, although may make Minecraft the slightest bit less laggy.

http://www.minecraftdl.com/4x4-ultra-low-res-texture-pack/

Ian