[KennyBlanken]

Discreet GPUs support encoding/decoding a lot more streams than the integrated stuff. Depending on the generation of Quicksync you have, the codec used by Zoom might not be hardware accelerated at all, though I think Zoom uses h264, so you'd have to be on some pretty old hardware.

[londons_explore]

I don't know about zoom specifically, but most video conferencing programs counterintuitively don't use hardware video encoders/decoders.

They use the GPU for visual effects (background blur etc), but then do regular CPU video encoding. That's why they gobble so much CPU!

I think that helps with system compatibility. Hardware video encoders are full of bugs and corner cases, and it's very easy for someone to end up seeing a garbled image when the bitstream was truncated or bad in some way.