If you have a lot of system RAM, say 16GB or more*, then using some of that RAM as a virtual disk drive can DRASTICALLY speed up rendering as RAM speed has at least 10 times faster access times even compared to really fast SSD drives.

There are many options for RAM disks, but I just found one that is free and does not have any size limits, unlike the 'free-for-personal-use' RAMDisk from DataRAM (Excellent program, but the free version is limited to 4GB drive sizes). ImDisk is easy to use, either from the command line or using its GUI applet from Control Panel. Here's a rundown on how to use it from the command line and also how to get it to create the RAM drive on startup if you want: http://forums.guru3d.com/showthread.php?t=356046 (Further down the page are more advanced uses, such as copying Windows' PAGE file to it, etc.)

Tutorials can be found on Youtube for setting up a RAM Disk using the ImDisk GUI. Here's one: http://youtu.be/yOWCo55KtXY
The main part starts at 20 seconds. It is sped up (Why? I don't know), but it's pretty simple to follow.

Russell1967

* = Remember, Windows 7 Starter and Home Premium (even 64 bit) are capped by Microsoft to support only a certain amount. Home Premium supports up to 16GB, no matter how much you actually have in your system. Home Basic supports 8GB and Starter only supports 2GB! You'll need Windows 7 Professional, Enterprise or Ultimate to access more (up to 192GB). All versions in their 32 bit varieties are limited to 4GB. This is a hardware limitation, not an artificial cap. System specs: Windows 7 Professional x64; Gigabyte Z77-DS3H motherboard with i5-3579K 3.8Ghz processor with 32GB RAM; Zotac GTX 760 w/4GB; 1xWestern Digital 1TB 10,000RPM HD; 1x Samsung 840 Pro SSD System Drive