Defiler suggested this a bit back in this thread, so I figured I'd work with him to see if I could get this to work. The result seemed pretty damn effective and rather easy to setup.

Why?

The cache folder gets filled with tons of small files such as portraits which easily get fragmented all over the place. This can drastically slow down EVE's performance, not in terms of FPS, but in terms of stuttering and loading times. In addition, hard drives are naturally slow at loading tons of small files, so there is an automatic speed increase regardless of fragmentation issues.

Obviously it would be best to put the whole EVE folder on a RAMdrive, which is quite easy, but that needs over a gigabyte of extra memory, which most people don't have.

Why would it be hard?

There are almost no free RAMdrives, and even the pay ones can be hard to set up. In addition, Windows doesn't, at least under the default configuration, support symlinks, a critical component of most other operating systems, which would be used to link the "cache" folder in EVE's folder to the RAMdrive. Both of these problems were solved...so read on.

System Requirements:

64MB of extra RAM that you are not using (I do not recommend this RAMdrive on systems with less than 512MB of memory).

Windows XP, 2000, or Server 2003. If you have Linux, this is probably a lot easier, sadly, but the guide doesn't cover it. This guide also won't work for Windows 98, but neither does EVE.

EVE on a drive formatted with NTFS. This is the default with Windows XP, but if you're using FAT32 this will not work. There are workarounds but you have to find them yourself.
Disadvantages:

If your cache goes above 64MB, it will no longer work. This is not a problem, as in 64MB you can fit a good few thousand portraits. If it really does get too large, feel free to delete some pictures.

You must run a batch file before starting EVE (to load data into the RAMdisk), and another after (to save the data to disk).
Steps:

Note: This will take you roughly ten to fifteen minutes, so set some time aside to do it. If you want to "undo" what you do here, simply disable the RAMdrive in the device manager and remove the link created in the EVE folder. You can also, of course, uninstall the NTFS Link utility.

Download this free RAMdrive driver and run it, extracting the data files to a temporary folder.

Go to Control Panel/Add Hardware.

Choose "Yes, I have already connected the hardware."

Scroll down the list and choose "add a new hardware device."

Choose "Install the hardware that I manually select from a list."

Choose "Show all devices."

Click "Have Disk" and choose the Inf file in the temporary folder from step 1.

Right click on My Computer, go to Hardware, go to Device Manager, and find the RAMdrive you just installed. Click the plus to see the driver itself in the category, and right click on it and select properties.

Select the disk size as "67108864" from the list and select S: as the drive letter (as that is what is used in the batch files).

Apply the settings.

Install the NTFS Link program.

Reboot.

Rename your cache folder in the EVE folder "cache2".

Create a "cache" folder in the newly created S: RAMdrive. Right-click drag it to the inside of the EVE folder, and select "create junction here." The link must be renamed to cache if it is called "link to cache."

http://myeve.eve-online.com/ingameboard.asp?a=topic&threadID=452570