Methods and apparatus dynamically reconfigure storage or channel capacities in a memory system. A fully-buffered dual in-line memory module (DIMM) is configured for a particular storage capacity and a particular channel capacity. An error may be detected at a memory address in some portion of the DIMM. To resolve the problem, the storage capacity or the channel capacity may be reduced and the DIMM may be dynamically reconfigured according to the reduced capacity. For one embodiment the DIMM may be reconfigured by mapping the portion of the DIMM containing the error as unavailable and taking that portion off-line without taking the entire DIMM off-line. For another embodiment the DIMM may be reconfigured by throttling the DIMM at a reduced frequency. The portion of the DIMM containing the error may be retested at the reduced frequency. If no errors are detected, the DIMM may be made available at the reduced frequency.