The separation of static (cold) and dynamic (hot) data to reduce write amplification is not a simple process for the SSD controller. The process requires the SSD controller to separate the LBAs with data which is constantly changing and requiring rewriting (dynamic data) from the LBAs with data which rarely changes and does not require any rewrites (static data). If the data is mixed in the same blocks, as with almost all systems today, any rewrites will require the SSD controller to rewrite both the dynamic data (which caused the rewrite initially) and static data (which did not require any rewrite). Any garbage collection of data that would not have otherwise required moving will increase write amplification. Therefore, separating the data will enable static data to stay at rest and if it never gets rewritten it will have the lowest possible write amplification for that data. The drawback to this process is that somehow the SSD controller must still find a way to wear level the static data because those blocks that never change will not get a chance to be written to their maximum P/E cycles.
