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Comment by gm-conspiracy | Hacker News Reader

So, what is a recommended, buildable GPU rig (bang for buck)?

i7 w/ dual 1060 GPUs?

I just built one partly for this purpose. I went with AMD's new Ryzen 1700. It has 8 cores and 16 threads. More threads are great if your application can use them. My understanding is that TensorFlow, for example, does[1]. i7s do better in applications that only use a single thread, but you get a really good cost/performance ratio for multi-threaded work from Ryzen [2]. The 1700 also comes with a serviceable air cooler, so you save some money there too.

The other components are a geforce 1060, Asus Prime X370-pro (lowest-priced x370 motherboard), and 16gb ram.

[1] https://stackoverflow.com/questions/39395198/configuring-ten... [2] https://www.phoronix.com/scan.php?page=article&item=amd-ryze...

edit: added other specs

my year and a half old rig is 2x 980ti and a 5930k, which is also my generic home computer. I only use AWS when it's a long running job and the weather is hot. It can really heat up your home on long running jobs, so keep that in mind.

I've been wondering: Is information processing "free" in terms of energy? I.e. if I put 100 watts in my GPU to make it do computations, will it heat my room for 100 watts' worth of heat?

I'm guessing yes, because where else is the energy going to go, but then we should probably be using heaters that are made of old/cheap GPUs, rather than just a resistor.

As a Canadian, I always feel good running compute-intensive jobs in the winter. It's heating as usual, with a side-benefit of computation.

I have a system to duct in, out or recurculate inside air as the seasons change. I can heat my home with 'waste' energy at idle, or switch to cool outside air for heavy jobs or late night gaming. In summer I exhaust outside, pulling cooler air from underground. It is slowly spawning its own system, only 1.5 years in.

Yes, according to the first law of Thermodynamics, energy is conserved; regardless of whether there is computation being done, 100W of electric power will result in 100W of heat being dissipated.

About heating with computers, There is a Dutch company doing this, https://cloud.nerdalize.com/. It's interesting to think about how their economics work, because the heaters will be switched off for large parts of the year, and for much of the day. They must be banking that computation won't get much cheaper over time (in terms of FLOPS/$) because otherwise it'd be hard to recoup their initial investment. In a sense, this almost looks like a bet against Moore's law!

Yup, all that energy ends up as heat in the room, just like a resistive heater.

However a heat pump can put even 400W of heat in a room for every 100W of electricity. That would be the benchmark for a lot of people in cold climates.

> a heat pump can put even 400W of heat in a room for every 100W of electricity

You mean it will transfer heat from the outside of the house to the inside? Over here we have the more traditional halogen space heaters (or central heating, with oil).

Yeah exactly, 100W is the thermodynamic "penalty" you pay to move that heat from outside to inside.

Space heaters have the same thermal efficiency as a GPU or a toaster (100%), though could still be an improvement if they heat more evenly or heat skin directly via radiation.

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