I may have misread your original post but your hostility isn't helping to clarify things. Instead of replying back "I was talking about the SSD cache" you repl

I may have misread your original post but your hostility isn't helping to clarify things. Instead of replying back "I was talking about the SSD cache" you replay back with "Well, it could hardly be below, could it. Was there an insight you wanted to mention?" So instead of clarifying things you decided to be rude. Now that I know what you're talking about, let's try to answer your question. There are SSD controllers that don't use a RAM cache on the drive. It's not necessary for performance and doesn't do as much as on a HDD if present. The main benefit of a drive cache while reading is for read ahead. This is not needed for an SSD as it doesn't have to wait for the sectors to show up under the head. The only thing that will affect things is reading file system blocks from the same SSD page/block. The md code already does this. If the next block requested is after the last blocks read it will use the same SSD. If the block is from somewhere else then it doesn't matter if it comes from this SSD or that SSD. Access time will be the same.