While Sizing a VMware VDI Infrastructure, we need to take a lot of things into consideration. What is the number of total desktops that are going to be provisioned, how many desktops will be used concurrently, what's the IOPS requirement, What's the Bootstorm IOPS blah blah blah blah.
It takes a lot of calculations to complete the sizing and its a tedious work. After all we are humans, we are known for committing mistakes. Take for example you made a mistake at the beginning of the calculation and you didn't realize it. Imagine if you'll have to redo the whole thing. Even if you got through the whole process without committing mistakes and it turned out to be a good solution, what if another requirement comes for more users next time? More users = complex calculations. What would you do then?
If you are a storage guy and you are more concerned about the performance of VDI and want to drill down to the IOPS level and see what kind of workloads are generated out of our infrastructure, you can check the link below which lets you work on the IOPS calculation part