Can you hear me? help me? Braw MultiCam edit & Render Speed.

I'm vary fan of BlackMagicDesign.
I have
5 URSA Broadcast G2 camera,
1 URSA Studio Camera 4K pro.
1 HyperDeck Studio 4K Pro.

And I do record all camera's ISO file Braw 12:1 format.

So....

When I edit these clips....
I run 6 or 7 sourcess multicam edit
( 4,5 Braw, 1 H.265, 1 ProRes422LT )
All clips recorded 3840 x 2160p 29.97
All Braw clips have some color edit ( Sharp, Radius, Lift, Gamma.... a little adjust)

Computer Specs...
i7 10700
RTX2060
32GB RAM
M.2 SSD


In multicam edit....
system parts loads.....
CPU 70 ~ 80 %
GPU 3D 60 ~ 70 %
G.Mem 90 %

in Rendering
CPU 60 %
GPU 3D 100% Video Encode 90 %
G.Mem 90 %

so....
I tried RTX3080 GPU
for this task.

But I can't obtain much more render speed.
RTX3080 render speed up about 5 ~ 10 frames more than RTX2060

Why this???
with RTX2060
GPU load 100%
but with RTX3080 GPU load 100% same but not much more speed.
only 5~10 frames faster....

This is right???

In my situation....
If I want to more comport and faster rendering speed
I have to have Mac M2 comptuer?

Not necessarily a Mac, but a beefier machine under either system. BRAW is using both the CPU and the GPU. It's a pretty easy codec, but nevertheless there's no specific hardware for it. 6 or 7 sources in that resolution are a serious challenge. Plus, you have H.265, which needs hardware decoding to run smoothly.
Did you already try to work in a HD timeline and transcoding the H.265 to ProRes or CineForm? Did you try to render into DNxHR, in case you are right now encoding straight into a GOP codec? If you work in HD and switch to UHD for rendering, the latter will still be slow.
If all of that is still not enough, you may need a Threadripper and a 4090 under Windows or a MacStudio.