[Inkscape-devel] looks like opencl should be able to do it.

So, long as you don't need to increase or change the number of elements in the vectors, basically no memory allocation, it looks like bulk vector operations are easy with OpenCL... here's an example where a vector id added:

https://github.com/rsnemmen/OpenCL-examples/tree/master/sum_array

But there's a wide variety of other possible functions...

I'll have to port the path rendering into OpenCL code and see how well it performs when I give it a vector containing all the path data in an entire SVG file in one go.

That should at least performance benchmark it and provide a proof of concept.