Yeah, I used to say the same about motorcycles... until I tried to do fuel-injection on an air-cooled Yamaha. The short version is it's nearly impossible to program a fuel-air table that can mix properly for the entire temp range of an air-cooled engine and still provide "accelerator pump" instant-enrichment AND proper timing advance/retard as needed. You'll either be always running rich, or too advanced for the temp, or you'll dump so much fuel it pops back through the carbs and starts fires.
Go liquid-cooled with proper thermal regulation, and bam... perfect metering 98% of the time, plus burns clean AND about 30% more power per CC. AND supercharging ceases to be a pipe-dream and becomes street-driveable.
The point being... things evolve. Lets face it; the last 30 years have been this stage:
Right now we're at about this stage:
You're looking at AIOs the wrong way.... you're looking at them the same way we USED TO look at the radiator in that T-bucket: a hand-crafted piece of equipment meant to last decades. Nowadays, radiators are a commodity product with a 5-12 year design life. But get this; all BS and "lost art" arguments set aside, today's automotive radiators, plastic tanks, limited lifespan and all... are cm³ for cm³ twice as effective at carrying away heat almost across the board.
AND they manage something those old brass & copper monsters never did: to not become an environmental disaster. No lead solder, and because of the way aluminum doesn't interact with common coolants used in ICEs, they almost never gel up and clog full of ethylene sludge that pollutes everything with a dozen carcinogens when they get melted down. AND because of this, flushing them before melting down the cores is now part of the recycling process; as is reclaimed coolant.
AIOs have become just that: a commodity product with a fixed lifespan and when they fuck up you replace the entire assembly.
Even the cheap ones have a decent micro-channel copper cooling block, glas-filled polymer plastic parts and one moving part with a ceramic bearing on the impeller (Okay; two moving parts on units with a mechanical flow sensor). By dint of their design they greatly reduce or eliminate three major issues:
1) Leaks. Sealed system, filled at factory with proper amount of expansion overhead. Unlike "custom system" coolers, all connections are permanently crimped, and decades of engineering history has already proven in automotive use that such hose connections are easily good for a decade under the most adverse conditions.
Argue all you like about leaks in principle; but the fact is that leaks in this type of assembly are so rare as to be statistically insignificant.
2) Noise. Liquid-cooling operates at much lower velocity than air-cooled solutions. Much less noise.
3) Dust contamination. Because they operate at much lower velocity, they carry much less particulate matter through the chassis. Dust accumulation in the case is greatly reduced.
Now environmentally... obviously not as friendly as big chunks of aluminum extrusion that melt down with near-zero waste. But that is getting better; automotive recycling processes directly apply, and as we learn to make electrolysis-fighting radiator/cooling-block assemblies, and the standard of the industry moves towards better, ion-inert coolants, that lifespan will only increase.
But first, the manufacturers have to realize that there is demand for this. And that comes from one thing: feedback from the people doing deployment. And that WILL come; as processors become more powerful and the need for higher processor density continues to increase, the reality that air-cooling just doesn't cut it anymore will sink in for even the most reluctant datacenter management teams. It really is only a matter of time; I fully expect to see processors factory-equipped with integrated liquid cooling become commonplace in my lifetime; same with GPUs.
We REALLY ARE at that point already; "The Future" is NOW. Cheers,
mnem
*AIO-Dwagon*