Interesting blog regarding the latest AGESA 126.96.36.199. Bios updates and what they mean in terms of tweakability:
Our data points indicate that Geardown Mode should be disabled for gaming if you can achieve your desired memory overclock with a 1T command rate. The opposite holds true if 1T CR proves too aggressive to reach your desired clockspeed--leaving Geardown Mode enabled may get you there. Finally, when it comes to GDM vs. 2T CR (not shown), specific memory throughput testing should be conducted as the balance of power will come down to your other memory timings.
I tried disabling the Geardown module as I can run a command rate of 1 easily.. WooHoo blue screen city baby and they came thick and fast too plus something i've never seen before it even blue screen in the bios!
As you can imagine that was quickly enabled again although not everyone may have the same experience. This is all a learning curve and it depends on what kit your using as well as a myriad of other things.
BankGroupSwap (BGS) is a new memory mapping option in AGESA 188.8.131.52 that alters how applications get assigned to physical locations within the memory modules; the goal of this knob is to optimize how memory requests are executed after taking DRAM architecture and your memory timings into account. The theory goes that toggling this setting can shift the balance of performance in favor of either games or synthetic apps.