Immersion cooling no longer reserved for the hyperscalers, HPC Immersion cooling has long been the domain of larger datacenter operators but with increasing density and therefore smaller datacenter facilities, there is a need for shops of all sizes to get around heavy-duty AC and air cooling. This is the target for German server maker RNT Rausch, which has teamed up with cooling …
I don't understand how you can say that.
Liquid cooling is just using a different medium - more efficient - to transport heat away from the microchips.
You still have to cool down the liquid and, in the absolute, you still have the same amount of heat to evacuate.
Liquid cooling is fine, but there will still be radiators. Maybe they'll be outside ?
"No need for air-conditioning. Just water conditioning, which is considerably more efficient."
Which means they can run hotter for longer producing more heat. Bit of an issue with Global Warming ATM. We need less efficient heat generators. Much less.
Actually, that was the problem these systems are literally fixing. You want more efficient systems even if they individually run hotter. But much like the problem of adding highway lanes, describing the tradeoffs is harder than it looks. Finding a good balance is more art then science, and is more about understanding the problem and tradeoffs. About the only constants in either highways or server thermal management are that No new lanes/Just add more lanes and "More Cores/More floors" are that the WRONG answer is almost always either extreme.
In the case of your post, the core issue you raise could be restated as "build and use the most efficient gear you can, but don't waste the power you are using, regardless of how efficient the servers are running"
Proof of work cryptocurrencies being the poster child for this, but ML driven stuff that hasn't been thought through is also setting large piles of money on fire on bad models that will inevitably be re-trained four or five times before being abandoned as defective.
That said these boxes with their 400w CPUs and 700w GPUs may be replacing 3-4 older servers, and they may draw in the mid double digits when idling out. Some even lower. Dumping air cooling has taken way longer than it should have, as it's horrible from an efficiency standpoint. Immersion is one approach to helping that, but you can also get great gains from block chillers like you see on high end gaming rigs. Industry just hasn't standardized on the specs for a "cooling bus" as well as other parts of the machines.
Ideally, the modular rack format would include a rack loop and a bottom of rack heat exchanger (to much lives top of rack these days, and the big boys are used to cooling being under floor tiles anyway) hooked to each chassis with an internal cooling loop and it's own exchanger that will be hooked to the rack. You loose a little efficiency there, but the trade of is better isolation for the racked gear, preserving the ability to quickly rip and replace gear on the fly.
Immersion systems squeeze a bit more thermal efficiency, which adds up, but it makes servicing gear a trial, as you have to "drain the tank" or "go fishing" to service parts. A fair trade off for bit barns, but less likely to appeal to those in smaller on-prem or edge sites.
Liquid cooling is fine, but there will still be radiators. Maybe they'll be outside ?
Yes. Specifically, they're saying they don't use chillers to reduce coolant temperatures below ambient. Heat is still removed from the coolant by using outside air.
If you're someplace with a moderate peak air temperatures (e.g., Britain or Tennessee) then you can lower coolant temperature to something well below the servers' preferred operating temperature just by using outside air, no additional chilling required.
For example the new Frontier supercomputer uses 85F (29C) water cooled by ambient external air. This eliminates the megawatts required by chillers and saves about $1 million annually in electricity costs.
You could also use a geothermal loop to cool the water, especially if there is a body of water nearby. A company near where I live built a new campus a few years back when they outgrew their startup spot. It includes a pond/lake a few acres in size that's a nice place for employees to sit outside and have lunch (or was until the pandemic) and also doubles as a geothermal sink for climate control for the whole campus including their datacenter.
Combined with solar on the rooftops and in surrounding spaces the entire site is designed to be net zero energy averaged over a yearly cycle.
"Immersion cooling has long been the domain of larger datacenter operators [...]"
I get your point, still... the consideration would have been more appropriate some years ago. As of today there is a decent offering for servers too:
https://www.grcooling.com/servers-for-immersion-cooling/
https://www.gigabyte.com/Solutions/immersion-cooling
https://www.amax.com/advanced-cooling-solutions/immersion-cooling/
And there is more...
Also, if you want to give it a shot:
https://www.pugetsystems.com/submerged.php
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