Go to Launcher Options > Java Settings > Memory > allocate at least 4-5 GB of RAM or else you'll run into stuttering/crashing issues. If you plan to use shaders, don't be stingy on that RAM :) Enjoy!
Installing a modpack using the Technic Launcher is easy. If you don't already have the launcher downloaded, visit our download page to get the latest version.
Type in the modpack name (TheFTBInfinity+ 1.10.2) or paste the following url into the search box.
Finally, click Install at the bottom right of the launcher after you select TheFTBInfinity+ 1.10.2 from the list on the left. The launcher will handle everything else!