In a small way, this has already happened, though. The intel Iris Pro has 1.5 GB of basically 4th level cache, shared between the GPU and the CPU.
I could see memory on the package, though, which might generate some of the benefits you're looking for.
Given that RAM is relatively simple, I wouldn't have expected yields to be such an issue. Also, since the marginal cost of a CPU is relatively low, I figured again, it wouldn't be a large hit to Intel's bottom line to overcome the yields or to give out new chips through warranty.
Remember that for buyers, RAM and CPUs are marked up significantly. A combined CPU RAM unit, would be justified to have increased price over just a CPU. As long as CPU-RAM Unit cost <= CPU + RAM, buyers wouldn't mind and society would end up better as a whole. Potentially making it worthwhile for Intel, regardless of loss in yield.
I am not very educated on the subject though, so I'll defer to your knowledge on it, and agree.
You mean 128 MB?
I've been waiting for this for 5 years, I don't know why it hasn't happened already.
- Optimized clock speeds, layouts, improved connectivity (i.e. increased number of RAM channels)
-- Reduced latency
-- Increased bandwidth
- Would there even be a need for an MMU?
-- CPUs wouldn't need to work with a variety of RAM types
-- i.e. Less complexity, fewer points of failure
The only cons:
- RAM size would not be configurable
Meanwhile, for better or worse, the majority of consumers can't re-configure their own RAM (Laptops/Smartphones), or on a desktop they don't know how. Businesses would either buy beefy hardware that suited their constraints or spend money on custom configurations. So this con only really effects hobbyists.