  This paper is devoted to the development of highly efficient kernels
performing vector operations relevant in linear system solvers. In particular,
we focus on the low arithmetic intensity operations (i.e., streaming
operations) performed within the conjugate gradient iterative method, using the
parameters specified in the CEED benchmark problems for high-order hexahedral
finite elements. We propose a suite of new Benchmark Streaming tests to focus
on the distinct streaming operations which must be performed. We implemented
these new tests using the OCCA abstraction framework to demonstrate portability
of these streaming operations on different GPU architectures, and propose a
simple performance model for such kernels which can accurately capture data
movement rates as well as kernel launch costs.
