Apple A5 Processor – Two Cores, But Clocked Slower than A4

While the new Apple A5 processor at the heart of the iPad 2 offers twice as many cores as the Apple A4 processor featured in the first generation iPad, it appears that each processing core is actually clocked at a slower speed. Some early tests performed by the iOSnoops team show that overall, each of the A5 cores runs at least 10-percent slower than the single core featured in the A4. While doing some early iPad 2 benchmarks, the team discovered by chance an interesting tidbit: the A5 doesn’t run at 1 GHz like the Apple A4, but is instead clocked around 890 MHz (the speed of the A5 does not seem to be constant, and varies depending on the apps running on the iPad 2). Overall, the speed of the A5 seems to oscillate within a window of about 40 MHz, as we’ve seen the processor run as low as 861 MHz, and as high as 894 MHz.

iPad 2 processor speed – Unlike the Apple A4, the Apple A5 speed fluctuates over time

iPad 1 / Apple A4 @ 1 GHz (left) – iPad 2 / Apple A5 @ 861 MHz (right)

While our tests show that the A5 is clocked at a lower speed than the A4, most likely to limit its power consumption, the presence of two cores makes up for the lower speed, as overall, the new processor delivers a performance improvement of up to 65-percent over its predecessor (see our upcoming iPad 2 benchmark tests for more details).