Future Chips Will Be Hotter Than Ever

https://en.wikipedia.org/wiki/Aluminium_nitride For anyone else who wasn't familiar with the compound.

""" Aluminium nitride (AlN) is a solid nitride of aluminium. It has a high thermal conductivity of up to 321 W/(m·K)[5] and is an electrical insulator. Its wurtzite phase (w-AlN) has a band gap of ~6 eV at room temperature and has a potential application in optoelectronics operating at deep ultraviolet frequencies.

...

Manufacture

AlN is synthesized by the carbothermal reduction of aluminium oxide in the presence of gaseous nitrogen or ammonia or by direct nitridation of aluminium.[22] The use of sintering aids, such as Y2O3 or CaO, and hot pressing is required to produce a dense technical-grade material.[citation needed] Applications

Epitaxially grown thin film crystalline aluminium nitride is used for surface acoustic wave sensors (SAWs) deposited on silicon wafers because of AlN's piezoelectric properties. Recent advancements in material science have permitted the deposition of piezoelectric AlN films on polymeric substrates, thus enabling the development of flexible SAW devices.[23] One application is an RF filter, widely used in mobile phones,[24] which is called a thin-film bulk acoustic resonator (FBAR). This is a MEMS device that uses aluminium nitride sandwiched between two metal layers.[25] """

Speculation: it's present use suggests that at commercially viable quantities it might be challenging to use as a thermal interface compound. I've also never previously considered the capacitive properties of packaging components and realize of course that's required. Use of Al O as a heat conductor is so far outside of my expertise...

Could a materials expert elaborate how viable / expensive this compound is for the rest of us?

I think diamond is even more thermally conductive than either. A quick google finds a number of companies working on silicon-on-diamond.

I don't think toxicity levels on compounds used in electronics has even been a stopper for furthering humanity

Or getting berylliosis from putting a drill through your electronic device before throwing it out

I mean, there's no real reason a chip has to be a wafer.

A toroidal shape would allow more interconnects to be interspaced throughout the design as well as more heat-transfer points alongside the data transfer interconnects.

Something like chiplet design where each logical section is a complete core or even an SOC with a robust interconnect to the next and previous section.

If that were feasible, you could build it onto a hollow tube structure so that heat could be piped out from all sides once you sandwich the chip in a wraparound cooler.

I guess the idea is more scifi than anything, though. I doubt anyone other than ARM or RISC-V would ever even consider the idea until some other competitor proves the value.

Start with an FPGA, they're optimized for performance, but too optimized, and very hard to program.

Rip out all the special purpose bits that make it non-uniform, and thus hard to route.

Rip out all of the long lines and switching fabric that optimizes for delays, and replace it all with only short lines to the neighboring cells. This greatly reduces switching energy.

Also have the data needed for every compute step already loaded into the cells, eliminating the memory/compute bottleneck.

Then add a latch on every cell, so that you can eliminate race conditions, and the need to worry about timing down to the picosecond.

This results in a uniform grid of Look Up Tables (LUTS) that get clocked in 2 phases, like the colors of the chessboard. Each cell thus has stable inputs, as they all come from the other phase, which is latched.

I call it BitGrid.

I'd give it a 50/50 chance of working out in the real world. If it does, it'll mean cheap PetaFlops for everyone.

Generally true.

But neural networks are non-Von Neumann, and we 'program' them using backprop. This can also be applied to cellular automata.

Doesn’t silane like catching fire when it sees an oxygen molecule? The other day I heard about it being used as rocket fuel for lunar ISRU applications.

A rocket and a sandblaster at the same time.

The point of improving the thermal conductivity of silicon is that silicon is what chips are made of instead of, say, diamond.

Of course cost would have to be acceptable.

I understand isotopically pure Si-28 may be preferred for quantum computing devices. The Si-28 has no spin or magnetic moment, reducing the rate of decoherence of certain implementations of qubits.

https://spectrum.ieee.org/silicon-quantum-computing-purified...

So, one power plant per aisle of a data center?

> watercooling is now officially recommended for new CPUs

First I'm hearing of this. Last I checked, air coolers had basically reached parity with any lower-end water cooled setup.

Will there be an official “cleared for frying eggs” badge? We'll have to do something with all that heat.

Modern computers should come with built in piezo, haptic and rumble motors that can emulate HDD, FDD and CD-ROM sounds whenever you start a game or app. Change my mind.

- Inner voice: "You don't miss the old PC noises, you just miss those times".

- Shut up!

The Model II was a loud beast. Its floppy drive drew directly from mains power, not a DC rail off the power supply, and spun all the time. The heads engaged via a solenoid that was so powerful it made a loud "thunk" sound and actually changed the size of the display on the built-in CRT.

The Model 12 and 16 improved on the design, sporting Tandon "Thinline" 8" drives that ran on DC and spun down when not in use, leaving fan noise that was quite tolerable.

The 90 nm Prescott Pentium 4 was much more power hungry than the previous 130 nm Northwood Pentium 4.

Even worse than the TDP was the fact that the 90 nm Pentium 4 had huge leakage current, so its idle power consumption was about half of the maximum power consumption, e.g. in the range 50 to 60 W for the CPU alone.

Moreover, at that time (2004) the cooler makers were not prepared for such a jump in the idle power consumption and maximum power consumption, so the only coolers available for Pentium 4 were extremely noisy when used with 90 nm Pentium 4 CPUs.

I remember when at the company where I worked, where we had a great number of older Pentium 4 CPUs, which were acceptable, we got a few upgrades with new Prescott Pentium 4. The noise, even when the computers were completely idle, was tremendous. We could not stand it, so we have returned the computers to the vendor.

The die was much smaller…

Which was huge in the era when CPUs didn't underclock themselves at idle to save power and coolers looked like this: https://www.newegg.com/cooler-master-air-cooler-series-a73/p...

Some coolers today still look like that but they're on chips drawing 35W or so while idling at <2W.

I mean, if what you want is P4-class performance, the modern semiconductor industry is excellent at delivering that with low TDP. An Apple A18 Pro [1] gives you over 7x the single thread performance of a Pentium 4 Extreme Edition [2] at 8 W TDP, compared to 115 W for the latter.

[1]: https://www.cpubenchmark.net/cpu.php?cpu=Apple+A18+Pro&id=62...

[2]: https://www.cpubenchmark.net/cpu.php?cpu=Intel+Pentium+4+3.7...