Hybrid-core computing is the technique of extending a commodity instruction set architecture (e.g. x86) with application-specific instructions to accelerate application performance.
Hybrid-core processing differs from general heterogeneous computing in that the computational units share a common logical address space, and an executable is composed of a single instruction stream—in essence a contemporary coprocessor.
Acceleration is especially pronounced when the kernel's logic maps poorly to a sequence of commodity processor instructions, and/or maps well to the application-specific hardware.
Hybrid-core computing is used to accelerate applications beyond what is currently physically possible with off-the-shelf processors, or to lower power & cooling costs in a data center by reducing computational footprint.
(i.e., to circumvent obstacles such as the power/density challenges faced with today's commodity processors).