Oxide Games has released an updated version of their Star Swarm stress test, for anybody with a Mantle-compatible AMD card who wants to test out the API for free. It should update automatically through Steam, and if you need to hunt the tool down to install it just search for Star Swarm.
So how come this new build boosts the Mantle performance? Oxide explains it was down to a simple mistake with the previous release version:
Did we crack some secret code or find a crazy new optimization? No, nothing so spectacular. The truth is that we made a mistake in our haste to deploy the build that stripped out the activation process. We didn’t follow our normal release process, and missed how a minor change in that build had disabled some of the Nitrous engine’s multi-threading features when using Mantle.
That’s now fixed, so “most configurations” running a Mantle-ready card will now seem performance improvements. That should include me too, as I tested out Star Swarm with the old build. Time to dip in again and see if I can squeeze out a few more frames.