How Much Disk Space?

[coder1]

I'm buying a new Linux system and I'm wondering where I can find guidance on how to think about how much hard drive space I need for SAS temp files.  I know procedures like proc sort use a lot of temp space.  I'm trying to be cost effective in trading off hard drive size vs. hard drive speed.  Of course I want the fastest SSD drive I can afford, subject to the constraint that I have a big enough drive.  For example, if the biggest data sets I work with are about 20G, how big of a drive do I need for SAS to run efficiently?  Would a 400G drive be enough to devote entirely to SAS temp space, or would I need to jump up to 1TB? 

[LinusH]

If this is a single user system, 400GB will suffice.