Matrioshka Brain

A type of megastructure involving a Dyson Sphere and using all or most of that energy for computation.
A Natrioshka Brain differs from Dyson spheres in all factions (except the Hyperion Federation) in that heat management systems do not exist. Instead, the Dyson sphere must be capable of withstanding the extremely large temperature. This is because another sphere will be built around the Dyson sphere to capture the heat of the first. The 2nd layer will provide a simlarly large computational output and also must withstand extremely high temperatures. Another layer is built around that, and more layers are added until the outermost layer is of a medium - low temperature.
The engineering and resource requirements for such a system are extremely large.
They exceed those of Dyson spheres by several orders of magnitude and also must be able to withstand the immense weight of each layer without use of support poles (as each layer spins at different speeds due to being at different radii form the star) and to prevent natural heat flow between the spheres.
However, the HF has the technology to re-use almost all of the heat loss on a regular Dyson sphere, in the form of the QEN, and is able to construct a Matrioshka brain with a significantly lower matter requirement. The HF leverages this advantage against the other factions, building many, extremely powerful data centers that can interface with HF starships via QEC. As such, a starship can exploit part of the computational power of a Matrioshka brain in real time. This allows mapping and predicting enemy behaviour with an extremely high accuracy. This data is fed to HF weapons so that it has a 99+% probability of a hit. This efficiency is a key factor when engaging an enemy with superior numbers.