Thanks, Grant. I've always just used the local preferences in BOINC. I now see what I presume is the default setting of 100 in my Rosetta prefs. But no corresponding setting in WCG (my one other project). No matter as I'm planning to continue sitting back per your suggestion and watch how BOINC balances the two projects. It piques my curiosity when, as it has a couple times over the past couple days, BOINC pauses a nearly complete Rosetta unit due in less than 2 days to download and start processing a shorter-duration OpenPandemic unit that is due in five days. All shall be revealed in the fullness of time.
Eric

WCG places that setting under Device Profiles. Once you select which profile to edit, you may need to select Custom Profile, then scroll down to the bottom of the page to see where you can set it, labelled Project weight.

What's easiest is to set Rosetta at say 50%, WCG at 25% and some orther project at 25% and let Boinc figure it out,which it will do over time. Just be sure to keep your cache sizes small so you don't run into deadline problems. With Rosetta's 3 day deadline if you have 3 days of work NO other projects will crunch because their deadline will be further out than 3 days.

Where are these resource share settings hidden?

In your account, Rosetta@ home preferences, Resource share.
The number there isn't a percentage. It makes up the ratio for the work to be done with the values from you other projects.
And changing that, will delay even further your Resource share settings being met.

What's easiest is to set Rosetta at say 50%, WCG at 25% and some orther project at 25% andlet Boinc figure it out,which it will do over time.Just besure to keep your cache sizes small so you don't run into deadline problems. With Rosetta's 3 day deadline if you have 3 days of work NO other projects will crunch because their deadline will be further out than 3 days.

1. I'm watching the three WCG work units (yellow box) just before the top one reaches 100%.
   
2. Since the Rosetta one (red arrows) has been waiting its turn, and has the earliest deadline in the list, I expect BOINC will start on it next.
   
3. But it starts processing the next WCG unit instead (green arrows).
   

Why the WCG and not the Rosetta? I can only guess it has to do with the "switch between tasks" setting, which I currently have set to a little longer than a Rosetta work unit requires.
Since Rosetta units require a longer processing time and carry tighter deadlines than the WCG OpenPandemics, I would think it best for BOINC to be toiling on two Rosettas and one WCG at a time, thereby completing 2 of the former and 5 of the latter every 8 hours. But I don't see how to tweak BOINC to achieve that if it is in fact a valid pursuit. Any ideas? Am I delving too deep, awakening a Balrog?
Eric

When I first saw your msg for some reason none of the other very good replies and suggestions were showing, nor were your useful images, so I've only just caught up.
If I can make some further suggestions...

Log into Boincstats, then go to BAM, then signature on the left column. Check setting in there like "Do not show projects with a BS-RAC lower than"

Also, can you see WCG in your stats on the main Boincstats page similar to my https://www.boincstats.com/stats/-1/user/detail/6470/projectList but change to your user number? If not, you may need to authorise exporting data in the WCG settings (daft EU legislation).

In short, no. Sounds very odd.
I run an i3-8350 remotely so I'm familiar with your PC, though mine has 16Gb RAM compared to your 8Gb, but that ought not to make any difference with just 4-cores.

The only thing I can ask is, on the Computing tab under Computing preferences in Boinc Manager, do you have anything in the section titled "When to suspend" ?
Everything in that section should be unselected.
In the section above, titled 'Usage Limits', both should be 100%

Any particular reason you stop Boinc so much? I leave mine on all the time, with very few programs that it slows down, so I set those as exclusive applications to pause Boinc when they run. 3 games, and VLC media player. Some stop the GPU, some stop the CPU also.

Or if you're always running something that needs some CPU for your work, tell Boinc to use less than all the cores, leaving some for you.

@EricM:

It seems that BOINC is having trouble deciding how much work to download for your computer. As I understand it, that decision is based in part on what BOINC has seen the computer complete in the past. Does the machine have an irregular usage pattern? (Powered off frequently/​irregularly? Variable amount of other work being done while BOINC is running?) The missed deadlines and high average turnaround time (2.81 days: only just within the 3-⁠day deadline) may be contributing.

Check all your Computing preferences. Post values/​screenshots here, and we might spot something amiss. Regarding pauses: do you have any restrictions in your Daily schedules settings?

To try to get some tasks, try increasing Store at least N days of work. Do it in steps: add around 0.4 (slightly more than one 8-⁠hour task time), save, wait a couple of minutes for BOINC to contact the server, and see if it downloads some tasks. If not, repeat. As soon as you get some tasks, reduce N again to maybe 0.3 (slightly less than one task) to avoid your machine getting flooded with work it cannot complete until BOINC learns better how long each task will take. Set Store up to an additional to 0, as at this stage the last thing you need is BOINC using poor estimates to opportunistically download even more work.

• My computer usage would be irregular seen over a couple decades, but is more regular the past few years. Typically, the computer is on 15 hours a day. Sometimes I'm working with it for much of the day, during which BOINC does not run. Other times, the sceensaver might come on 5-10 times per day and run for an hour each time. I have the screensaver set to come on after ten minutes, then I think the comp sleeps after an hour. But, depending on how far back we go -- I ran SETI@home for 20 years -- there are times when the computer is off for a few days or a few weeks, and there was a ten-year era when it would often be running only on weekends.
  
• See my computing preferences screenshot below.
  

@Robert, I think your comment regarding deadlines and the server determining reliability of my computer could explain at least part of the reason for Rosetta being stalled the past few days. I was away Sun-Tue, so maybe the server gave up on the partially completed work units on my machine? If the cause is something like that, it makes me think that Rosetta is less tolerant that SETI was in this regard.
Eric

I turned that nonsense off. Go into Boinc's properties and change the "switch between applications" to a huge number. I set mine to a year. I do not want stuff changing before it's finished.

EricM,

Looks like you need to give more details about not finishing the current task. If it includes leaving a CPU core idle, that's a problem. If it's switching to running another task instead, that's normal.

6/24/2020 7:16:42 PM | Rosetta@home | Result hbnet_surface_design3_0.7_SAVE_ALL_OUT_IGNORE_THE_REST_3yb2cw0d_949347_1_0 is no longer usable
6/24/2020 7:16:42 PM | Rosetta@home | Result miniprotein_relax2_COVID_SAVE_ALL_OUT_IGNORE_THE_REST_9db4ko0a_949448_2_0 is no longer usable
6/24/2020 7:16:42 PM | Rosetta@home | No tasks sent
6/24/2020 7:16:42 PM | Rosetta@home | Project requested delay of 31 seconds

6/23/2020 3:51:03 PM | Rosetta@home | Task hbnet_surface_design3_0.7_SAVE_ALL_OUT_IGNORE_THE_REST_3yb2cw0d_949347_1_0 is 1.74 days overdue; you may not get credit for it.  Consider aborting it.
6/23/2020 3:51:03 PM | Rosetta@home | Task miniprotein_relax2_COVID_SAVE_ALL_OUT_IGNORE_THE_REST_9db4ko0a_949448_2_0 is 0.70 days overdue; you may not get credit for it.  Consider aborting it.
6/23/2020 3:51:03 PM | Rosetta@home | URL https://boinc.bakerlab.org/rosetta/; Computer ID 3864355; resource share 100
6/23/2020 3:51:03 PM | SETI@home | URL http://setiathome.berkeley.edu/; Computer ID 8050566; resource share 100

EricM,
Rosetta@home currently has so many new users that it's not keeping up with the demand for tasks.
As for being paused mid-task while another BOINC project run, that's normal if you have more than one BOINC project providing tasks. Tasks close to their deadlines get higher priority to run, and tasks for the other project catch up on run time later.