It is even more tenuous than that. If just one of a company's fabs goes down much of the imaging industry will have problems. A few years ago when the earthquake affected Sony's Kumamoto sensor fab it caused some serious issues for some camera vendors. Nikon for example had announced their DL 1" sensor compact line to compete with Sony's 1" sensor cameras and reportedly due to the earthquake they delayed and eventually completely scrapped the project.
Are sensor fabs functionally similar enough to CPU fabs that if China tried to take back Taiwan, or just made it hard for Taiwan to ship chips to the West, the Japanese sensor fabs could retool for chips?
Absolutely not. The lithographies, processes, and packages are completely different. Some sensors are still made on 300nm processes, useless for modern CPUs. 45 nm is considered cutting edge for imaging sensors, but would be a huge setback for computing. Intel, GlobalFoundries and even IBM fabs would be much better.
The increase in CPU power doesn't become apparent until you start to use vectorization heavily or use your CPU for floating point-heavy scientific computing.
Some of the code I've written can speed up 3x just by using newer SIMD instruction sets and bigger caches. It's unbelievable until you see it.
I also manage HPC clusters, so we see strange effects when developers excessively hand-tune their code for a specific architecture.
Well of course hpc can benefit from 13 years of cpu advances. (And gpus). Noting that sse4 was even available on it. My point was we still wouldn't be relegated to stone age if we were stuck on 45nm processes, and we could also benefit from better architectures.
