I don't know if this is still the case, but back then the likes of Synopsys charged a lot of money for what was very limited controller functionality; you were stuck with their frustrating support channels and generally dumpster fire firmware. Our controller was fully custom to our needs, supporting more optimum refresh schemes tightly integrated with our application, and multiple memory protocols (not just DDR3), and I don't remember what else.
At least we were able to modify the training algorithms and find the improvements, rather than being stuck with the usual vendor "works for us" response. Especially with something like commodity DDR, where our quantities don't command much clout. But it was a bit of an ordeal and may have contributed to us buying in a controller for our next gen (not DDRx). But I think we're going the other way again after that experience..!
At least we were able to modify the training algorithms and find the improvements, rather than being stuck with the usual vendor "works for us" response. Especially with something like commodity DDR, where our quantities don't command much clout. But it was a bit of an ordeal and may have contributed to us buying in a controller for our next gen (not DDRx). But I think we're going the other way again after that experience..!