That is a problem I'm facing right now. I need to specify the hardware that will run my piece of software. The thing is: the project isn't finished yet, and I need it running in "real" conditions before I can go on, conditions which I cannot reproduce at home; what I can test at home barely scratches them. We don't have much money to spend (it's a research at college). Feels like a catch-22.
How can one get a good approximation of what setup is needed without having the means to simulate accurate work conditions?
If you need to test your setup on a machine with less specifications then your own machine then you could use a virtual pc setup to test it and just keep reducing the virtual pc settings until your software stops performing adequately.
If its the other way around, then I think, as Paul said, its a case of begging or borrowing until you get what you need.
Can't you beg, borrow or steal the biggest hardware you can get, and then once it's in those "real" conditions, start reducing the capacity either by hardware changes (removing memory, underclocking) or by software (running other programs that consume memory or CPU cycles) until you find a point where it doesn't work as well as desired, and then specify a minimum hardware level that will meet or exceed those conditions?
Not sure why this popped to the top of my list today, but allow me to also suggest:
Rent an Amazon | RackSpace cloud instance that “sounds big enough” and try your app out on it. You can get a pretty good approximation of whatever hardware scale you'd like — if you're talking in the range of PC-type hardware, and not, “I think we're gonna need a couple of Crays in here…”
来源：https://stackoverflow.com/questions/170939/how-to-specify-the-hardware-your-software-needs