Memory Divider This is one of the most Confusing aspects of A64 Overclocking. There is ALWAYS a memory divider. Setting the Memory to 1:1 means that the HTT bus is multiplied by the CPU Multiplier and then Divided by the CPU Multiplier to set the Memory speed. This means that it is OK to run your Memory at its peak efficiency and still go higher with your HTT bus if your CPU can take it. Take note that I said its "OK" not advisable. There are still sufficient tests out there showing that running a 1:1 ratio will garner you the best overall performance. I plan on adding a few test results in the next week or so showing the difference in performance using a higher memory divider than CPU Multiplier.
Since A64's use an On chip memory controller, the Ratio must be calculated a bit differently than old. 5:6 is NOT always 5:6. See that chart at the end of this post for a prety darn close representation of what each divieder is doing.