RAM disks can be useful in many different ways. Once you allocate a part of your RAM to be used as a disk, you can do all sorts of things with it. The usefulness of a RAM disk increases with size as well. The larger the RAM disk is, the more things you can do with it. Here are some potential uses/benefits:
Private Data Security: When the image file feature is disabled, the contents of the RAM disk will be completely gone when the computer is powered-off or restarted. In this case, there is no possibility of sensitive data recovery, even when using forensic data recovery applications. For certain services or applications this is an important attribute that contributes to the protection of private data or information.
Faster Software Installations: You can move your Windows TEMP folder to the RAM disk. When installers run directly from RAM, program installations will be faster. It also means that your Windows disk will take less write hits, something that is very beneficial to SSD's.
Faster and more secure Web Browsing: A RAM disk can also be used to hold your Temporary Internet Files folder. Moving this folder to a RAM disk will result to faster and more responsive web browsing, and once again you will be saving your system disk from a lot of unnecessary writes. Any browsing leftovers that you delete from the RAM disk would be instantly flushed, with no possibility of recoverable data traces (as is the case when the internet temp folder resides on a normal disk).
Faster Media Conversions: You can use a RAM disk as a temporary storage medium to convert media files between different formats. For example, converting audio or video files is much faster when you are using a RAM disk as the source and/or destination for your files. Of course you have to allow enough RAM disk space for such a task; it all depends on the size of the media you will be converting.
Forced Folder Relocation: You can also use NTFS junction points to force certain folders and their contents away from C: and onto the RAM disk, with all the speed and responsiveness benefits that this entails.
Better Overall System Security: You can use a large RAM disk combined with a top sandboxing program like Sandboxie. Many people use Sandboxie to safely test unknown programs, or to isolate their web browsing from the rest of the system. If you opt to move Sandboxie's default sandbox folder to the RAM disk, this will force all sandboxed programs to run directly from RAM, with all the speed benefits that this entails.
Such usage delivers great system security against malware threats. When the RAM-residing sandbox is emptied, this means that all your personal internet-related traces will be completely gone with no chance of recovery. Once again such usage is also beneficial to SSD's because it allows you to test programs and browse the internet without incurring any SSD write hits.
These are just some of the uses that you can get out of a large RAM disk.