anexanhume
Veteran
What is more expensive for the transistor budget (which could mean yields or bottom line costs) on an SOC, increasing the clock speeds, adding cores or doubling the RAM?
RAM isn't really a concern. That isn't their product so they don't have to worry about yields. Only unit price. There's also no problem stacking 1GB versus 512MB in the package seeing as how all the other vendors do it.
For the transistor count and clock frequency, it's not always a simple equation. In the simplest terms, if you have one failed transistor per x mm^2, then a chip twice as big is twice as likely to fail to yield. But that's not all. The larger your chip is, the less efficient you likely use your wafer (because, remember we're putting rectangles on a circle). As far as clock speeds, that also effects yields indirectly. Since these are all intended to run at one frequency, they either past the functional test or they don't. So, there's likely going to be some sort of bell curve in terms of how many chips yield at their desired frequency, so they need to pick a frequency that is reasonable given how the parts are testing.
And how would that compare with increasing storage?
NAND is one of the biggest single costs in the system. However, it is also the ONLY thing they increase the price of for. For instance, for ~30 more worth of NAND, they are charging 100 more in the 64 versus 32gb iPad. So, they don't really have any problem adding more NAND if they want it in there.
The problem for Apple compared to other manufacturers is that they will produce and ship far more, so any incremental cost would have a much greater multiplier effect to the overall costs and ROI on the life of a project like the iPad 3.
But their profits and revenues also scale. And any NRE (non-recurring engineering) is not multiplied no matter how many iPads you make. More is always better assuming you can source components and consumer demand is there.
With higher-resolution screen, apps. and content could have assets which make greater demands on RAM and use more storage. Perhaps increased RAM and increased storage would result in a better overall experience than increasing CPU or GPU performance?
While apple is very efficient with their RAM usage in iOS, I think there's no question they would benefit from 1GB. Heck, they could even do dedicated VRAM like the Vita. The good thing about Apple is that they understand the user experience end of it, and shipping a product is not just about specs and getting it out. They see themselves as users of their own products and they will demand a smooth experience.