So I went back and found some receipts, and it turns out that we’re pretty much on the same page. This thing was actually about $900 of hardware, which was basically a higher end mid tier build. I remember looking for high quality components but I wasn’t grabbing high performance ones. I’ve probably spent $300 on drives and RAM so cost per year is under $100.

As far as how much I value my time - one does not spend a mere 30 minutes swapping a mainboard out of the everything-box that runs all your shit, so I value hardware stability quite a bit. I moved most of the time-consuming compatibility hacks into docker containers the last time around so hopefully it’s a lot easier next time. I have to deal with this stuff all day long at work so my appetite for PC projects at home is very low. If I can throw some more cash at it to stave off the need to swap out a drive or even the whole PC for a couple more years I’ll gladly do it.

There tends to be a correlation between quality, longevity, and price. It’s not a perfect fit but it’s definitely a thing that exists.

I built a brand new cutting edge PC for a family member in 2011. They wanted to change careers and get into IT and figured they needed the bestest fastest PC they could afford. Anyway, it worked great until they decided it was time for a new one in 2019. I got to keep the 2011 PC in exchange for some assistance with selecting components for the new build. I put in a shiny new SDD, ebayed 16GB of old RAM that was the fastest thing the motherboard could handle, and I’m still using it as my primary server / workstation / web browser / cloud backup automation controller / etc. It cost more upfront but the amount of time that 2 different people have not spent with fucking around building new PCs has more than offset that in my opinion.

So this PC is on its 3rd round of HDDs and 2nd round of RAM but that was only to boost performance, not because of a hardware failure. I haven’t lost a power supply, motherboard cap, fan motor, or USB port on it yet. That’s pretty remarkable for a 14 year old machine that’s been running 24/7. The 2019 build hasn’t had a hiccup in almost 6 years now either.

I think Schneier wrote this well before quantum computers were a reality - did he miss something fundamental in regards to them? Quantum computers are relatively new but the theory behind them is nearly a century old.

*One of the consequences of the second law of thermodynamics is that a certain amount of energy is necessary to represent information. To record a single bit by changing the state of a system requires an amount of energy no less than kT, where T is the absolute temperature of the system and k is the Boltzman constant. (Stick with me; the physics lesson is almost over.)

Given that k = 1.38×10-16 erg/°Kelvin, and that the ambient temperature of the universe is 3.2°Kelvin, an ideal computer running at 3.2°K would consume 4.4×10-16 ergs every time it set or cleared a bit. To run a computer any colder than the cosmic background radiation would require extra energy to run a heat pump.

Now, the annual energy output of our sun is about 1.21×1041 ergs. This is enough to power about 2.7×1056 single bit changes on our ideal computer; enough state changes to put a 187-bit counter through all its values. If we built a Dyson sphere around the sun and captured all its energy for 32 years, without any loss, we could power a computer to count up to 2192. Of course, it wouldn't have the energy left over to perform any useful calculations with this counter.

But that's just one star, and a measly one at that. A typical supernova releases something like 1051 ergs. (About a hundred times as much energy would be released in the form of neutrinos, but let them go for now.) If all of this energy could be channeled into a single orgy of computation, a 219-bit counter could be cycled through all of its states.

These numbers have nothing to do with the technology of the devices; they are the maximums that thermodynamics will allow. And they strongly imply that brute-force attacks against 256-bit keys will be infeasible until computers are built from something other than matter and occupy something other than space.*

I’m not a physicist but quantum particles were still considered to be matter the last time I checked.

Kessler Syndrome, here we come!