I can confirm what Tony said. AMD cards used literally 2 or 3 seconds of the CPU, that's it. However, it's a different story on Nvidia. I haven't run Milky for a while, but if my memory served me right, it could use almost a whole thread/task. Even when Boinc Manager said it only used a fraction of a thread, but actually if you check Task Manager and you'll see it used way more than that. I couldn't remember exactly if it was Einstein or Milky, but I do know they're kinda similar on Nvidia cards. I'm not sure about the Titans as I don't own one.
Milky also had this annoying thing. Maximum WUs you can get was 900 WUs, doesn't matter if you spoofed 10 GPUs or 64 GPUs. All you can eat is 900 WUs. The things is ... you'll have to finish all 900 WUs before you can get new work. Then sometimes it caused your machine just sitting idle for hours before it got new works. I don't know if they fixed this or not, but that was pretty annoying when I ran it a while back.
While the VII can run 30 plus tasks at once, but the most points it can produced is still 3 tasks. The VII is beast, but it's also very tricky to work with. 1X PCIE will work, but won't get the max performance out of it. Even the CPU load can affect its performance, specially when undervolt. A Radeon VII should be good for 1.75M to 1.8M per day on Milky. If anything less than that, by a significant amount, then you're doing something gimping its performance.
That's AMD favor projects like Einstein and Milky. On Nvidia favor projects like PrimeGrid/Collatz/Amicable/etc ...etc ... the VII can hold its ground too. As y'all can see, most of my damage on Sprints/Marathon, on GPUs came from my VIIs. I don't own anything higher than 2060 on Nvidia's side. But I still managed to stay competitive when Nvidia favor project announce. Part of it is speculative bunker, other part was the VII.
The only thing I hate it was the heat. I literally haven't turn on my heater for the last 2 years during winter. Just pop Einstein or Milky on and my whole house will be warm enough
Anyways, Milky is not in the way of current FB competition. So i thought I'd share some of my experiences on it for the fellow crunchers.