Writing for Seeking Alpha, Mark Hibben suggests that Apple (AAPL 1.27%) might enlist the semi-custom design services of struggling chipmaker, Advanced Micro Devices (AMD -0.35%), to build a custom-tailored processor for Apple's MacBooks. In fact, he pegs those chances as "good."

I, on the other hand, think that this is highly unlikely.

If Apple wants a semi-custom MacBook processor, Intel could do the job, too
One key argument that Hibben makes is that Intel's (INTC 0.64%) PC processor designs are designed in a "one-size fits all" fashion to serve the requirements of a wide range of PC customers. By commissioning a semi-custom chip from AMD, Hibben argues, Apple could get exactly what it wants/needs without any of the additional "bloat" present to support other PC makers' designs.

The first (but certainly not the biggest) issue here is that Intel, too, offers semi-custom design services for big customers. Intel's semi-custom pitch has been more targeted toward the data center (where major customers are willing to pay to get exactly what they want), but there is no fundamental reason that Intel could not build "semi-custom" processors in the PC segment for the right customer.

There is little need for semi-custom MacBook processors
Although Hibben argues that Apple might be better served with custom-tailored parts for the MacBook, I disagree. Take a look at the following diagram that Hibben pointed to in his article:

Source: Intel via Seeking Alpha.

Notice on the big green rectangle that there are two black rectangles? The longer one is the main processor complex. This contains the CPU cores, graphics/media engine, and the rest of the performance-critical components.

The smaller black rectangle is the PCH or the "platform controller hub." This is an auxiliary input/output chip that that, among other things, allows the processor to talk to other components. Hibben argues that Apple "isn't using a lot of that stuff," and for the new thin-and-light MacBook this is true, but all of this functionality is stuffed into a cheap-to-make auxiliary silicon die and can be disabled if need be.

The idea that Apple should ditch Intel and commission a totally new, semi-custom chip from AMD because it doesn't need to use the USB and Serial ATA functionality present in Intel's Platform Controller Hub seems ludicrous.

Would Apple really trust the Mac to AMD?
Another issue here is that AMD's notebook processors haven't been competitive with Intel's for a while, all things considered. It is not a coincidence that AMD has continued to bleed share to Intel in the notebook market for a long time.

In order for AMD to have a chance at winning the MacBook contracts (either via off-the-shelf parts or a semi-custom arrangement, as Hibben suggests), it will need to be able to deliver leadership PC processor products (MacBooks are premium products and Apple is likely to want to use the best chips possible). Given Intel's vastly greater ability to invest in its architectures and designs, as well as its manufacturing leadership, it's hard to see this happening.

It's all very unlikely
I would peg the chances of Apple swapping Intel out for AMD in the MacBook as extremely low. Intel's PC processors are, in my view, the "gold standard" in the industry and Intel's track record suggests that the company knows how to consistently deliver winning PC products. AMD, on the other hand, has a lot to prove and I doubt that Apple wants to be its guinea pig.