Cost of ownership is an addition of investment, selling and cost of operation.
Too much focus on efficiency can cause buying expensive hardware that do not return on their investment.
Too much focus on performance can cause expensive operation because of cooling and power consumption issues.

I know the above statements are a bit cliches, and are easily said without any risk. I understand that.

Without wanting to put the sensible middle of the road solutions mentioned here (Ryzen 3700X, Bronze PSU, no Christmas tree motherboard but with decent VRM) to the discussion we still do not have any bearings regarding:

initial costing of rig
its use of power
and its output of calculations (RAC)

It is easy to state an opinion like this. I know. Writing a message in a topic is not so difficult and not so time consuming. Trying to get answers to the three questions above takes loads of time. While we all need to do exactly the same thing to measure something that can be compared with the results of someone else. Only then we are able to get some unbiased answers. Don't take me wrong, I do not doubt at all the judgment and experience of the respondents in this topic, and do not want to discuss their opinions. We only should try to give some foundation to all those mostly valid opinions in some numbers.

So if we should like to have some answers we should benchmark, benchmark and benchmark again. But before we can start benchmarking we should agree on what to measure and what information should be involved. This is a challenge itself :) (and I think it should be a separated topic as well). Benchmarking in a reproductive way is difficult, and do not be surprised that later on advancing insight will force us to alter that benchmark itself.

A first step can be is defining how to benchmark and how we sensibly can measure what we want to know. To get thinking started:

RAC: How to measure? How long to get an average result with enough resolution, against what side conditions (what do we allow to run on the OS besides the calculations)?
Measuring power consumption: what meters to use (define a standard?), what to measure? Again how long to get an average result (we can Make RAC leading for this period)
Most difficult and chaotic variable: against what cost hardware can be brought and sold economically. Many depencies, in what part of the world is brought and sold, special deals etc.

So do not start testing yet, we first need to agree how to test.

https://www.cnx-software.com/2020/04/23/50-odroid-c4-raspberry-pi-4-competitor-combines-amlogic-s905x3-soc-with-4gb-ram/amp

Could this be a candidate for beating the efficiency of ryzen?

but if we contributed every phone, tablet and low-mid end office machine, typically with 2-4 cores, our computing capacity could increase by orders of magnitude. (I.e., we have way less than a million hosts and there exist billions of personal computing devices in the world)

For as many of of those devices there are, many are of such low capability they are of no use to many projects.
And for those that are of use, their frequent use for what they were designed for by the users means they often can't contribute much during those periods, compared to more capable systems.

And you need to keep in mind efficiency isn't actually about low peak or maximum power use- it is about energy used over time to complete a task.
It's no good having a device use 1W if it takes 1 month to produce a result when something that uses 1kW can produce the same result in a matter of seconds. Yeah, it's instantaneous power consumption is a lot higher. But it uses less energy to do the same work. And the fact it can do so much more work over the same period of time as the slower device makes it even more useful to a project.

Unread Message 94951 - Posted: 19 Apr 2020, 23:16:02 UTC - in response to Message 94937.

I think the new longer tasks should get more than the credit awarded for running 4 1gb tasks, the idea being that they can't be run by everyone and that by definition means older and slower pc;s which should be enouraged to be replaced or updated as over time they simply won't be able to keep up. How much more depends on the priority the Project places on these new workunits, if they are just new workunits than only a minimal amount of credit above the amount 4 1gb tasks would get, on the other hand if the new tasks are a higher than normal priority than a higher credit should be given to encourage people to crunch them instead.

Where exactly to position the credits between 1x1GB and 4x1GB depends on the availability of processor cores and memory in the clients capable for the 4GB jobs, you can judge that better than I.

So, it seems reasonable that these 4GB work units should come with a premium on credits granted. But how much of a premium is reasonable?

There are many ways to look at it, so we thought we'd open it up for discussion. Please keep things respectful. Probably best to just state your own perspective on the topic and not address other posts directly, and certainly no need for rebuttals here. We're trying to brainstorm.