Binning. By detecting defects and working around them by making a design that can function without some portions of the processor and disabling a defective part of a processor, and selling it as a lower grade, one can have a higher rate of salable processors.
Splitting up the market to permit use of price discrimination. If I know that people who want error-correcting memory are less price sensitive than those that are, I have a separate line of processors and motherboards that costs much more and avoid offering error correcting memory on my cheaper line. This converts consumer surplus into producer surplus.