Need Advice: Llama.cpp Tensor Parallelism RPC vs Single Node Performance

I have a 5090 and a 4090 sitting on two different pcs. Right now I am running Gemma4 31B across a 10gbe link using RPC. I get about 28 tps on a fresh session, and scaling down to about 17 tps by 100k context.

I want to know if it's worth moving the 4090 to the same PC and what types of performance uplift I might see. I am using Tensor Parallelism not layer, self compiled llama on windows 11.

I get about 24-26 tps on the single 5090 running the q4 on new low context session, for reference.

Thanks.