While many are looking forward to the next-generation Apple (AAPL 0.06%) iPhone because it will likely be thinner, feature a larger screen, and even offer improved pixel density on its display, the really impressive part about the new iPhone will probably be the A8 processor. In fact, while Apple's A7 was touted as "desktop class" (and in many respects it was), the A8 should bring new meaning to that phrase.

The Apple A7 was a massive jump from the A6
The Apple A7 chip, according to Apple, sported "over 1 billion" transistors and fit all of that into a die area of 102 square millimeters. Apple has claimed that this is roughly twice the number of transistors found in the prior-generation A6, which implies some pretty substantial efforts on the design side of things as Samsung's 28-nanometer process did not offer anywhere close to twice the gate density of the 32-nanometer process.

Furthermore, the A7 also offered roughly twice the performance of the A6 chip, thanks to a significantly beefed-up CPU core, much faster graphics block, and a lot of system-level improvements. The trade-off here is that the A7 also seems to consume more power than the A6 at full load, but because the chip is much faster it can finish workloads more quickly, racing to an "idle" state more quickly and ultimately saving power consumed.

The A8 could be an even bigger jump
In moving from Samsung's 28-nanometer process to TSMC's (TSM -3.55%) 20-nanometer, Apple will again roughly double the number of transistors that it can put in a given chip area. Assuming it sticks to the roughly 100 square millimeter die sizes that have characterized its last couple of product generations, Apple should have north of 2 billion transistors at its disposal. To put this into context, this is about 43% more transistors than the Intel (INTC -5.42%) Haswell chip found inside the MacBook Air.

It is very likely that with such a transistor count, as well as the performance/power improvements that the 20-nanometer transistors bring, the iPhone 6 will offer peak CPU and graphics performance that is well ahead of many of the Intel Bay Trail-M based notebooks and Bay Trail-D based desktops that will be shipped during this back-to-school season.

Did you just say Apple's iPhone 6 could outperform PCs?
Yes, you heard that right: Apple's iPhone 6 could offer more performance than many PCs. In fact, the A7 chip inside of the iPhone 5s already offers superior graphics performance to Intel's Bay Trail-M and Bay Trail-D parts found in low-cost notebooks/desktops, respectively, and the CPU performances of Bay Trail and Apple's A7 -- at least in the few cross-platform benchmarks out there -- seem roughly equivalent (A7 has higher single-core performance, but Bay Trail has more cores).

With A8, this will only get better for Apple, particularly as Intel is not planning to refresh its low-end PC chips this year in any meaningful capacity. The higher-end Haswell/Broadwell parts should still be noticeably faster (particularly Broadwell), but the fact that Apple will soon be selling customers a phone that will be across-the-board faster than the lowest-end PCs is quite exciting.

Foolish bottom line
The upcoming iPhone 6 will break ground in a number of key ways, but by far the most interesting from a technological perspective will be its performance. Apple's chip designs are world class, and with the increased transistor budget afforded to it by TSMC's 20-nanometer manufacturing process, the iPhone 6 should offer pretty unreal levels of performance.

Desktop class, indeed.