I have a 2009 Mac Pro with dual 3.2 GHz hexcore Xeons (so 24 threads) and 2 older GPUs and 48 GB RAM that cost less than $700 for the whole thing. I'm beginning to think I lucked out on it more than I already thought I did.
The Power9 18-core / 72-thread is going to come in at under 150W total.
The main advancement the past decade has been in power-efficiency. Cloud-scale providers keep their computers running at max load as well, so 500W does add up over months / years into a sizable amount of money.
Especially when you consider that 500W computer needs 500W of Air-conditioning, so the "True cost" of a 500W computer is roughly ~1200W or so (500W from the computer, 700W to power an air-conditioner to move 500W of heat)
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A 12-core / 24-thread AMD Ryzen 3900x is just $500, with a total system cost under $1500. The big advantage of a Ryzen 3900x would be a max clock-rate of 4.7 GHz, while your Nehelem 2009 computer is... what? 2.5 GHz? Probably? And computers of that age didn't have deep sleep capabilities, wasting even more power than usual. Modern computers idle at 20W, even servers and desktops. Tons of power-saving features these days which add up.
I think a typical $1500 computer these days would be more than twice as fast with 1/4th the power usage. I don't think anybody seriously in this hobby should be using anything as old as Nehelem these days.
IMO, the price/performance "old computers" seems to be Haswell (~2014 era servers), if people want to buy old equipment. But 2009 is definitely too old, there are lots of used servers that are a little bit more expensive but a LOT more power efficient / faster in practice.
I thought air conditioners/heat pumps were supposed to be substantially better than 1w of heat moved outside per watt of electricity?
15 BTU/hr == 5 Watts of cooling per Watt of input.
So it appears you are correct. To move 500W watts of heat, you only need 100W of air conditioner power.
For example, the Dell PowerEdge R630 (2014-era) server is in and around $600 to $1000 on Ebay, and will be more power-efficient and faster than any 2009-era system.
I think 2014-era servers are where the price/performance point is for the home-server enthusiast, especially if we're talking about sub $1000 price points.
https://www.ebay.com/itm/Dell-Poweredge-R630-2x-Xeon-E5-2640...
2x8 core dual socket Intel Xeon E2640 v3 (Haswell) with 64GB of RAM. Its an auction, so it will probably go up another $100 or $200 from there, but I would expect it to sell well south of $1000.
2014-era equipment is the current price/performance king for home hobbyists. Obviously, a modern desktop with all the bells and whistles is a bit more expensive at $1500, but for $6oo to $700, you can get a pretty good 2014-era system.
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My rule of thumb is to buy something 5-years out of date. That's roughly the time when businesses get rid of old equipment and upgrade. So 5-years old equipment tends to win in price/performance.
Well, I guess the Mac Pro is fine for that, as long as you're fine with the Mac OSX operating system. The Mac Pro line hasn't really had many updates, so maybe the 5-year heuristic doesn't really apply.
The TDP on the 18 core (and 22 core as well) is 190W as listed on Raptor’s website.