Formatting the RAM Disk
Here's where things diverge a bit. For some users, the new drive instantly appears in Windows Explorer (alongside the C: drive), and formatting it is as easy as right-clicking the RAM-disk drive and selecting Format to bring up a box of options. Leave the allocation capacity as is, change the file system to NTFS, check the Quick Format option, name the volume whatever you like, and click Start.
Unfortunately, things aren't always so simple. Sometimes, the drive won't appear in Windows Explorer automatically, and you'll have to allocate the space and start the formatting process manually.
If that happens to you, open the Start menu, right-click Computer, and select Manage. The Computer Management window will open. In the left pane, click Disk Management in the Storage options. Now, look for the 'Unknown' disk at the bottom of the central window; it should have a black bar next to it, with the size of the RAM disk and the word 'Unallocated' underneath the bar.
Right-click the unknown disk and initialize it, leaving the MBR option checked. The disk's designation should change from 'Unknown' to 'Basic'. Next, right-click the black bar and select New Simple Volume. Follow the steps in the wizard that appears, and when you're prompted with the formatting options, use the details described previously. Give it any drive letter designation you want. (I like to use R: for mine.)
Now you have a working RAM disk. You can find it in Windows Explorer the same way you would any other drive. But what are you going to do with it?
Moving Browser Caches to the RAM Disk
Many people use RAM disks to store their temporary Internet files, since a RAM disk's volatile nature wipes the data when the computer shuts down. (Unless you're automatically saving the disk image, of course.) Some users say that storing files on a RAM disk speeds up browsing, too, but I've never noticed a significant performance gain; if nothing else, moving your caches to RAM keeps needless writes off of your SSDs.
Here's a more detailed explanation of how to move the caches of the big three browsers.
Internet Explorer: Microsoft keeps things fairly simple. Go to Tools > Internet Options > General, and then click the Settings button in the Browsing History portion. In the window that pops up, you'll see a Move Folder button in the Temporary Internet Files section. Click it, and then point IE toward a cache folder on your RAM disk.
Firefox: You can't change how Firefox stores its cache without tinkering with the browser's configuration. Type about:config in the address bar, press Enter, and click through the warning. Right-click anywhere on the Preferences list, and then select New String. Enter browser.cache.disk.parent_directory (note the underscore between "parent" and "directory") as the Preference name, and then list the file path to your RAM disk as the string value. (In my case, I would use R:\ as the value.)
A Cache folder containing Firefox's temporary files will appear in your RAM disk.
Chrome: Since Chrome won't let you change the location of temporary Internet files, you'll have to change the way Windows handles the program. It's not as difficult as it sounds.
Right-click Chrome in the Start menu, and select Properties. In the Target: box, you'll see Chrome's file path, which ends in 'chrome.exe'. Place your cursor at the end of the path, press your keyboard's spacebar once—that's important—and then paste or type the following text:
--user-data-dir="your folder path"
Replace "your folder path" with the path to a cache folder on your RAM disk, but leave the quotation marks intact. Here's an example of how the full Target box should look afterward:
What do you use your RAM disk for? Spread the knowledge by sharing your tips and tricks in the comments.