In order to achieve affordable operating costs, exascale computers must consume far less energy per processor than current computers. Computing on exascale machines will be very different from computing on existing machines because of this low-power requirement. For instance, data movement will be far more expensive in terms of energy consumption than floating-point operations, and erroneous computations will routinely occur during the course of a simulation. Thus the entire concept of the "cost" of computational algorithms will change and algorithms must have the capability to detect erroneous computation and either correct it or tolerate it in some quantifiable manner.
Thermal radiation transport is generally far more computationally expensive than the other physics components in high-energy density laboratory physics simulations, chiefly because the transport equation is seven-dimensional. Thus it is critical to develop efficient algorithms for radiation transport.