Continuing on the Device Emulator, make sure to check "DeviceEmulator V2 - how did we get a 40% improvement in performance?", a great post from Barry Bond, Device Emulator's architect:
The DeviceEmulator V2 is significantly faster than the V1 emulator you're used to. Most of the performance wins come from a small set of optimizations in the ARM-to-x86 JIT and the MMU emulator. These wins improve raw execution of ARM instructions, so all applications and OSes benefit...
Barry goes on describing six "simple optimizations" that provided a "substantial performance win":
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