1. A method comprising: receiving a host memory subsystem on a host hardware platform, the host memory subsystem including a memory device; performing a stress test of the memory device in the host memory subsystem with a test component embedded in the host memory subsystem, including testing an operation of the memory device at a performance level higher than a minimum rating guaranteed for the memory device; detecting specific bits that experience failure in response to the stress test; and mapping out the detected specific bits to disallow use of the detected specific bits in runtime operation of the host memory subsystem.