Apple turned heads early this year when it unveiled the 1GHz A4 Processor, an Apple-branded processor that is now used in the Apple iPad and Apple iPhone 4.  The A4 relies on an ARM Coretex-A8 core and a PowerVR SGX 535 graphics processor.  Prior to the A4, Apple powered the iPhone and iPod Touch with processors developed and manufactured by Samsung.

But last year, Samsung announced their own 1GHz  ARM Cortex-A8 processor called the S5PC110A01 aka Hummingbird.  Recently, the S5PC110A01 has appeared in some of Samsung’s flagship devices, including the Samsung Wave, Samsung Galaxy S Android smartphone, and the Samsung Captivate, which is based on the Galaxy S platform.

So what’s the difference between these two processors?  According to TechInsights, not much.

Both processors feature a 1GHz ARM Cortex A8 with a 45nm core, and the aforementioned PowerVR SGX 3D engine from Imagination Technologies.  The Samsung processor was developed in conjunction with Intrinsity, a fabless semiconductor company that was later acquired by Apple.  Furthermore, the cache used in both processors is manufactured by Samsung.

TechInsights concludes that the ARM core used in the Samsung S5PC110A01 and Apple A4 are identical.  From a hardware standpoint, there is very little difference between the A4 and the S5PC110A01.

From a software standpoint, however, the difference between the A4 and S5PC110A01 is unclear.  It’s likely that Apple optimized the A4 to decrease power consumption in the iPad and iPhone 4.  But this optimization isn’t necessarily unique to Apple – in fact, Intrinsity likely played a large role in optimizing both A4 and S5PC110A01 processors.

So, there may be little difference, if any, between the A4 and S5PC110A01 processors in Apple and Samsung devices, respectively.  Apple’s acquisition of Intrinsity however, does suggest that the company is aggressively pursuing custom designs down the road that will help to differentiate future Apple processors from other ARM designs.