During our testing of the iPhone 5, we have discovered that Apple’s dual-core A6 processor operates at fluctuating speeds, contrary to the recent report from Engadget that states the A6 maintains a clock speed around 1.3GHz. Using the latest Geekbench build (2.3.6), our iPhone 5 (A1429) has been clocked multiple times at both 1.1GHz, and 1.3GHz. The A6 does appear to stay at 1.3GHz for about 95 percent of the time, but there is no doubt the clock speed can fluctuate when needed.
We also believe the A6 processor to be a underclocked dual-core processor (which fits into Apple’s habit of underclocking all of their processors) capable of considerably lowering its output, regardless of clock speed, and the numbers seem to back up this theory. Tested at 1.29GHz and 1.3GHz, the A6 scored 243 points lower in the overall Geekbench score, and 437 points lower in the processor floating point performance test, at the higher speed of 1.3GHz. Click on the images below for the full benchmarks.