Inspired by a thread in the WCG forum I thought about what it costs to provide the computing power of world community grid.
So let’s do the math! Of course, it is not possible to figure out the answer exactly – but at least one can get a rough idea with some estimates.
I will run the following thought experiment: what if one wanted to provide the current computing power of World Community Grid, by building a large number of one of the crunchers I have myself – a Ryzen 2700 run at base clock rate, undervolted, built as cheap and energy-eficient as possible? As I have precise data for my own crunchers, this is a good starting point. I know what they cost, what electricity they use, what the points output is. Additionally, I tried to optimize everything as good as possible for lowest overall cost per amount of work done (hardware + electricity cost). So this thought experiment might yield a number near the current minimum cost needed to replicate WCG’s computing power.
Keep in mind, that the 3rd generation Ryzens are even more energy efficient than my Ryzen 2700. However, with the higher hardware cost, they are only more cost-efficient overall when the electricity cost is very high. Else they are still in the same region as a Ryzen 2700.
How many Ryzen 2700’s could run WCG?
WCG’s output was on average 1056 million points per day in march 2020 (whenever I speak of points, I mean WCG points, 7 of which equal 1 BOINC point).
My Ryzen 2700 run at 3.2 GHz would have an output of approximately 80,000 points per day, if running the current mix of sub-projects (about 58% Mapping Cancer Markers, 25% Microbiome Immunity Project, 13% Smash Childhood Cancer, 3% Africa Rainfal Project, 1% Fight AIDS@home 2 and <1% Help Stop TB)
So that would make 1056 million points / 80,000 points = 13,200 of my Ryzen 2700’s to run world cummnity grid!
What would it cost to do that?
First, you would have to buy the hardware. I checked the prices for the components of my Ryzen 2700 where I live and translated that amount to USD. Elsewhere, prices might be a bit different, but should be in the same ballpark.
|CPU Ryzen 2700 with boxed cooler||190 USD|
|8 GB RAM||35 USD|
|128 GB SSD||25 USD|
|Power Supply (80+ Gold)||30 USD||(running 2-3 machines on 1 PSU with power splitting cables)|
|Overall Cost||360 USD|
So to build 13,200 of these, you would have to invest 4,752,000 USD. Let’s say you would run them for three years, before you replace them with more modern machines. After that, you might sell every replaced machine for 100 USD. That would make a yearly hardware cost of approximately 1.1 million USD.
However, the second big cost factor would be electricity. My crunchers are highly optimized by running them at low clockrates, undervolting and using efficient power supplies, but electricity is still a major cost factor. One is drawing 75 W from the wall when running at full load. So 13,200 of them would draw approximately 1000 kW or 1 MW around the clock and therefore consume 8,672,400 kWh per year.
Now what does one Kilowatt hour (kWh) of electricity cost? Variation is very high around the world. Where I live, the cost is very high at approximately 0.29 USD per kWh. Calculating with what WCG’s members pay on average per kWh might be another approach, however I can only guess this number. Here you can see, where WCG’s volunteers come from. Most come from the North America, Europe and Asia. In North America and Asia electricity rates are on average more on the low side. In Europe they are more on the high side. From the link we see, that approximately half the volunteers come from North Wmerica and Asia, the other half from Europe. So with average 12 US cent per kWh in the US and about 24 US cent in the EU, the average might be the middle of these numbers or 0.18 USD per kWh. With that electricity rate, our 13,200 crunchers would generate a yearly electricity bill of about 1.6 million USD.
So added together the yearly hardware cost and the yearly electricity cost would be about 2.7 million USD to replicate WCG’s computing power.
is the real hardware running WCG better or worse?
Now what is the real cost of the hardware volunteers use on WCG? I can only speculate what that will be, but here are some estimates.
Luckily, one can get some good answers regarding which CPUs really run WCG. Have a look on the Host CPU breakdown on Boincstats, sorted by average credit.
On the first place you can for example see the Intel i7-6700. Most of the CPUs seen on the top of the list seem to be a bit older than the Ryzen 2700, but nothing super old. All in all I would guess the electricity consumption to be quite a bit higher that in my Ryzen 2700 example above, due to the higher average CPU age, but also due to the fact, that not all machines used are optimized to maximum efficiency – which can make a tremendous difference.
On the other hand, the hardware cost might be lower. First because of the higher age of the machines. But also because a part of the machines are certainly not dedicated crunchers, but are used anyway for other tasks. In this case I would count the hardware cost as zero.