[Buraksr]

I would argue the opposite, that it is a huge deal for defense.

Imagine if the situation is missile defense, both the missile and the defense systems are computerized and not only the milliseconds but also the microseconds are the difference between a hit and a stopped missile. Whoever had the newest fab node would have a notable advantage in being able to push their system harder. It could be better ML in missile to lock on and dodge, vs the defense system predicting paths as fast as possible with as low latency as possible to defend a ship or similar asset.

Its asymmetric in the example of course, but both sides would be doing both shooting and defending.

[FrojoS]

Your scenario is not founded in reality. Few problems that involve computers are limited by or can primarily be solved by computer technology. In your example, one of the main challenges is that every missile defense system can be overwhelmed by shear number of attack missiles.

Have a look at what type of microchips are used in “cutting edge” military equipment like fighter jets. They are often decade olds. More speed is simply not important enough.

[Buraksr]

I think what you say is correct, its so much easier to fire a missile than it is to stop one. Honestly, reliability and cost are bigger drivers than raw performance. The scenario is a bit bad I can admit, and did admit.

But if we were in desperate times, I think the limits would matter and fab tech would be an important strategic asset for what it enables. The nature of it is that its easier to attack, but we hopefully have something to defend.

Intrinsically larger process nodes are better for analog and have uses even as new fabs come along. In 7nm your analog signals are not treated very nicely, but these are important for sensors. Also power electronics are not really on the newest nodes either. The microchips are old because they get the job done and I don’t think we feel so threatened to push the limits.

[xupybd]

Not only that but smaller cores are less radiation resistant. Meaning more likely to get interference from natural radiation sources. So less reliable.

[blackoil]

Are defense systems on such cutting age tech? I would have assumed they are using 40-200nm as development cycle for such system is usually in decades.

[Buraksr]

Generally old chips are good, depends on the purpose. Some things like the f35 would like to use TSMC’s fabs. But not every chip is for only processing and larger process have their advantages for certain applications like power, analog, and em hardening

[megous]

Also the fab for a 20year old process is probably easier/cheaper/faster to re-build in case the enemy destroys it, than the fab for 5nm process you've been building for 4 years.

Nevermind the nation probably has more than 1 of such old fabs, so it can't be technologically decapitated by destroying a single precious 5nm fab it has.