“We overclocked this CPU to 5GHz” means all bets are off. You often have some headroom to overclock on stock voltage/cooling but always need to go above and beyond for more extreme overclocking. This particular setup apparently was using a very fancy 1700ish W chiller, and a 1300W PSU for the chassis itself.
Also, this is a Xeon part, so one you’d expect to see in servers or workstations. You don’t want that sort of thermals anywhere close to a data centre rack, and the sort of business with the budget to give you this sort of CPU wouldn’t want to have their IT department assembling custom coolers like this.
All of this assumes, of course, you can run the chip stably. That's more or less a given at stock speeds, operating within the vendor's operational specs. Once you start overclocking, all bets are off. Extreme overclocking (the sort that uses liquid nitrogen or this sort of chiller) never lasts long. Again, something an enthusiast overclocking for a few FPS on a gaming rig might be willing to live with, but a problem that's seriously disruptive in the sort of environment a Xeon is likely to be deployed.
(EDIT: Fixed chiller power and added stability concerns)
It was 1770W, not 1000W
and produces 1.7kW of cooling
If you need to overclock you don't get this and have to buy more expensive cooling and probably need to de-lit (remove the heatspreader) of your above 2000 dollar CPU (which can permanently damage it) to improve the thermals because Intel - unlike AMD - didn't solder their heatspreader. Even then, you're not guaranteed to get a chip which can run 5 ghz on all cores 24/7. The best 18 core HEDT from Intel I have seen to date was running 4.5ghz on all cores 24/7 with delidding and a custom loop.
The 28 core Xeon which this probably is based upon runs 2.5 ghz stock and can boost to 3.8 ghz on a single core (3 or 3.2 ghz on all cores I believe).
It’s like extrapolating from an athletes 100m sprint time to their Marathon time. In other words, taking peak performance and presenting it as something that can be sustained for long periods.
But yeah, this is absolutely the case with the Intel demo. Their demo proved that the chip can run Cinebench at 5GHz.
Cinebench is not the heaviest load and it finishes very, very quickly. If they showed Prime95 AVX with small FFTs running for a couple hours, that would count as stable :D
Edit: And here I learn to read the article first: It's almost definitely that they couldn't achieve it with stock air cooling based on the setup described in the article.
For comparison, a Ryzen 1800X does 0.49 watts per square millimeter and has a lot less square millimeters (probably less than half)
[0] https://www.anandtech.com/show/11839/intel-core-i9-7980xe-an...
The entire system pulled over 2kW of power, a lot of that dedicated to cooling.
This isn't merely "you need aftermarket cooling" but rather "you need to dedicated serious resources to cooling this".
A really cool feature the new AMD CPUs have is that they have a very well implemented turbo, if you give it good cooling it will know how to exploit it and give you more power.
As a side note, is a weird feeling running a 4 core/4 threads CPU when now workstation CPUs could reach up to 64 threads
Overclocking almost always shortens life expectancy of the CPU.
What Intel in this demo did is strapped you behind the car and drove a 100 meters dash proclaiming - look he survived, he 'ran' that 100 meters run like a champ, it's possible to run this fast.
You can change pretty easily the maximum clock multiplier the CPU is allowed to use (on K CPUs at least) -- but doing so without proper cooling and proper power supply will just crash.
SOME 'good' bin CPU can be overclocked a fair amount without extra power/cooling, but it's always touch an go.
My workstation still has a 4600K i7 that has been running at 5ghz for probably 5 years, without even pushing the voltage. It's in fact a lot quicker (single thread) than a more modern system I built since. That was a "good bin"! the 4500 and 4600 were known for their overclock potential.
On the flip side, if you buy a car that has an engine that produces only 200 horsepower, but then add a large turbocharger that boosts the output to 400 horsepower, you're likely to run into problems. The cooling system might not keep up. The engine block internals might not be able to handle the extra pressure. The transmission or differential might not be able to survive the excess torque. Your clutch might slip.
Similar idea to a CPU. Transistors can only switch so fast. If you buy a CPU that Intel labels as a 5 Ghz CPU, Intel is guaranteeing those transistors can switch fast enough to maintain that clock speed. If you buy one that's only 4 Ghz and try to overclock it, there might be some transistors in that chip that can't switch that fast. Increasing voltage can help, but now you're creating more heat.