Do you know how to change the amount of RAM given to minecraft? Too bad, that won't help with Twitch. Fortunately for you, this thread exists. Let's go Here's your twitch client. You might expect to go into "My Games" or even the modpack itself to edit ram. NOPE. Click the action triangle™. Can't quite see it? There it is. Select "Settings". Then select "Minecraft" from the side bar. Scroll down a bit, and... Bingo. Set this to something reasonable for your computer and modpack. Congratulations, you can now -actually- run that brand new modpack!