We get asked this quite a lot by normal store owners who want to see how good their host really is. However, our Magento Benchmark service is only really aimed at web hosts themselves.
So to answer a popular question (albeit briefly):
There isn’t a standardised test – as there is a myriad of different testing procedures.
Apache jMeter is our tool of choice, it is a little tricky to configure – but allows you to tailor your test exactly to your type of expected customers browsing habits. By controlling the number of pages they browse, page view time, replicating checkout process, logging in/out etc. It is as close to real-world simulation as you will get.