Orchard 1.2 was released yesterday with lots of performance improvements. In fact, aside from a few bug fixes and a couple of minor new features, Orchard 1.2 is all about improved performance.
If you are running Orchard 1.0 and Orchard 1.1 and finding the performance of your Orchard Website a little sluggish even with the Warmup Module, you should upgrade your Orchard Website to Orchard 1.2. Startup performance has improved and common day-to-day administration tasks just seem snappier. The Warmup Module in Orchard 1.1 is now native to Orchard 1.2 in Performance Settings as well.
You can download Orchard 1.2 from CodePlex here.