A webapp has as a central component a relatively heavy algorithm that handles geometric operations.

There are 2 solutions to make the whole thing accessible from both high-end machines and relatively slower mobile devices.

I will use RPC's if i detect that the user machine is ''slow'' or else if i detect that the user machine can handle it OK, then i provide to the webapp the script to handle it client side.

Now what would be a reliable way to detect the speed of the user machine?

I was thinking of providing a sample script as a test when the page loads and detect the time it took to execute that.

Any ideas?