Some tests have been performed on a Google Nexus One running Android 2.2 (Froyo) vs a Nexus One running Android 2.1.
Early results indicated that in some cases Android 2.2 runs 450% faster than the previous 2.1 OS.
The speed tests were done using a tool called Linpack and the speed increase is believed to be because of JIT compliation in to the kernel. When using Linpack it tests how fast the phone can operate and provides results where you can then compare numbers.
The LINPACK Benchmarks are a measure of a system's floating point computing power. Introduced by Jack Dongarra, they measure how fast a computer solves a dense N by N system of linear equations Ax = b, which is a common task in engineering. The solution is obtained by Gaussian elimination with partial pivoting, with 2/3*N3 + 2*N2 floating point operations. The result is reported in Millions of FLoating-point Operations Per Second (MFLOP/s, sometimes simply called FLOPS).
* the Nexus One running Android 2.1 gets about 6.5-7 MFLOPS
* my HTC Hero averages a measly score of about 2 MFLOPS (the phone is pretty slow indeed)
* Nexus One running Android 2.2 - A whopping 37.5 MFLOPS.
Although the 450% is impressive, it is more likely that this wont be 450% across the board although the Android 2.2 user did say the Nexus One was more responsive in the UI which is always a good thing.
Via: Android Police