Note: I'm working on a far future sci-fi setting for a novel series which aims to blend elements of both "soft" and "hard" science fiction concepts. I'm aiming for the series to be as grounded and consistent as possible whilst still allowing some elements of speculative physics etc. Megastructures, including Dyson-scale, are quite common and the majority (>90%) of people in any given star system live in space.
One civilisation in the setting has its capital in a binary star system, with the primary being an F6V star which supports one habitable planet and associated habitat swarms. The star has a partial Dyson swarm, primarily used for power generation/beaming. The star's distant companion is a relatively hot and massive white dwarf star (roughly analogous to Sirius B for now until more details are figured out) with a surface temperature of roughly 25,000K.
The society in question is known for its high integration with an AI system housed in a Matrioshka Brain around the white dwarf, used for housing uploaded minds, defence and economic coordination, scientific research and universe simulation. The system also supports the civilisation's e-democracy by managing the government and tallying votes from the system's population of several hundred trillion.
It is my understanding that a large Matrioshka Brain offers greater computational capacity but suffers from signal propagation delay due to the light speed limit at which individual elements of the brain can communicate with each other. My question is that would the White Dwarf strike a good balance between capacity and computational speed due to the more compact nature of any Swarm/Brain, or would it be more feasible for this structure to exist around a small red dwarf star instead?