Rel test and qual takes months. The lower the possible temperature acceleration the longer the required testing (and/or larger the sample size). It is exponential with temperature.
With something like a console it is very difficult to get either sufficient temperature acceleration or quantity.
Adding RAM (different density or more chips) is a much more minor change as far as the qualification does. The SoC, VRM, cooling solution and case design are much more serious contributors.
Plus if you did end up with a dual foundry solution you have 2x the testing to do.
Now the ICs and modules I work on are tested outside of the system in simpler test boards, making it easier. I don't know if MS is doing that, but we at least see the racks of systems. Quite possibly both are being done and both are still in progress.
Maybe AMD is also doing tests on the SoC in simpler test boards but X SoC per board. Perhaps 10 per board in huge ovens/cooling chambers. (One of my higher power projects needed to be in cooling chamber due to total 1kW power dissipation. No need to run the oven to heat it up for temperature acceleration.)
Still don't think these changes are much in the grand scheme of things. (An up clock << 1175 MHz and different memory density or number of modules. Hey, do you fear for the reliability of your laptop or PC each time you replace the memory with standard non-over clocked memory in a different density? No, you don't because those modules were qualified separately already and because your motherboard and APU or CPU were qualified for the maximum number of DIMMs and chips per DIMM already. And because there are industry standards for DDR3, etc.)
Keep in mind that AMD and Nvidia are experts at re-binning, re-clocking, re-fusing, (re-branding
) and matching the same original silicon with a new laser mark with all kinds of new combos of memory, clock, cooler, PCB, VRM, etc. And new "name/brand". They do it all day and it is not that hard to do the derivatives or the re-brand.
The real difficulty would be a new SoC. THAT would be difficult. That rumor is fairly crazy but we can not say how crazy without access to insiders and the timeline. If it started early 2012 (almost two years before launch) (and if the rumor is not fake) then it is not so hard (not really any harder than the first SoC), especially if it is based upon the same blocks already fabricated and verified (that could actually make it *EASIER* than the first SoC design was!!!). (In other words more CU of the exact same CU and another ESRAM block of the exact ESRAM block.)
So if it started early, no problem. If it started late, big problem. If that new one is not done then you *really* do not want to say anything. If you announce the new SoC and then have to ship the old one due to a glitch/problem with the new one you will *really* look bad. So a new SoC in process looks pretty much like a bad rumor. Nothing said except a leak or two which might be totally bogus too. And if the leak is from a developer half a dozen times removed from the MS or AMD labs then you can not expect enough accuracy in the leak to be able to tell if it is real or not.
Not that I any lending any credibility to the pastebin or similar. Just filling in some design and industry related facts for fun, since I am a big hardware fan and a hardware designer. So don't go full fanboy on me if you don't agree. It is just a big interest for me. And if the hardware rumor thread causes you to go full fanboy then you don't need to read it do you? (Unless you are a reputation management professional.)