Methods, systems, and devices for speed bins to support memory compatibility are described. A host device may read a value of a register including serial presence detect data of a memory module. The serial presence detect data may be indicative of a timing constraint for operating the memory module at a first clock rate, where the timing constraint and the first clock rate may be associated with a first speed bin. The host device may select, for communication with the memory module, a second speed bin associated with a second clock rate at the host device and the timing constraint, where the host device may support operations according to a set of timing constraints that includes a set of values. The timing constraint may be selected from a subset of the set of timing constraints, where the subset may be exclusive of at least one of the set of values.