This guide is only recommended to people with 6 GB or more RAM available on their computers.
A couple of years ago hard disk speeds weren't exactly an issue, but as time passed and frequently used data kept getting larger and larger it became the Achilles' heel of our computers. Fortunately nowadays you can get an SSD and instantly see a drastic increase in boot up and application loading times; any task that requires reading or writing files becomes noticeably faster.
There exists, however, another storage method that is approximately 20 times faster than an SSD (or 70 times faster than an HDD). I had forgotten about it, but in my frustration against LoL's Mac client's game loading times I remembered; RAM. It is one of the cheapest components to upgrade and modern computers have plenty of gigabytes available, so why not use some of it as a fast storage medium? In my case I used this extra storage to speed up LoL, but this method can be used to speed up any application or game; you can even use it to speed up tasks such as video rendering by putting your video files in it. To store files in our RAM we need to create what we call a RAM disk; I'll explain how to do this for Mac OS X and Windows.
If you are a Mac user, just open your Terminal app and type in:
diskutil erasevolume HFS+ 'FastStorage' `hdiutil attach -nomount ram://8388608`
This will create a 4 GB HFS+ formatted RAM disk named FastStorage, which is big enough to put LoL in. If you plan to use your RAM disk for a different purpose then calculate how many megabytes you need and multiply that number with 2048 and replace 8388608 in the above command with the number you came up with.
For Windows users there exists many available software for creating and using RAM disks. Doing a quick google search I found SoftPerfect's product which is free for non-commercial use and seems to be able to do the job pretty well.
One important thing to remember while using RAM disks is the fact that your data inside it will be gone after you turn off your computer, or power cuts off unexpectedly, therefore if you want to retain any changes made to those files then you should copy them back to your normal storage before shutting down.