Apple's new iPhone 6s and iPhone 6s Plus are powered by a new A9 processor that promises to be up to 70 percent faster than last year's A8. But not all A9 chips are created equal, it seems. Depending on which manufacturer made them, they come in slightly different sizes.

Given the popularity of the iPhone — which saw 13 million units sold during launch weekend alone — Apple must rely on multiple component manufacturers to meet consumer demand. Those chosen to produce the new A9 processor are Samsung and TSMC.

Chipworks has discovered that those manufactured by Samsung are around 10 percent smaller than those manufactured by TSMC. While Samsung's measures 96mm², TSMC's measures 104.5mm².

In theory, this could mean that Samsung's chip is every so slightly more efficient than TSMC's. However, it's highly unlikely that this difference would be noticeable in everyday use — and there's no way to tell exactly which chip your iPhone is powered by.

Apple may have plans to use Samsung's A9 processors exclusively in the future if they are indeed better, but while demand is at its peak, the company cannot afford to rely on just one manufacturer.

The upcoming iPad Pro, which goes on sale in November, is also powered by a faster version of the A9 processor dubbed A9X.