Suggested Specs for memory
- Low usage: 512MB RAM
- Medium usage: 1GB RAM
- Heavy usage: 2-4GB RAM
Hard drive space is totally contingent upon the size of their archive. If you calculate the size of the data, and then multiply that by 3 (copy of original and then thumbnail copies and such), that will give you a good estimate. Say you have 20GB of data, you probably won't need more than 60GB of hard drive space.
Generally, we think the faster the better. If omeka is the only thing running, anything over 600MHz will work well, but 1GHz and above are best.