Ok, so - your cached reads on the Rasperry are faster. So what? That's nice in theory but has no practical relevance. You were talking about server usage. How will you benefit from faster cached reads, if the network connection of the device is limited to 12MB per second? If you add a USB GBit network adapter, you get a bit fast performance, but still - that's still way slower than even the continuous read performance of your attached USB storage.|
As said before - on the Banana Pi, you can achieve much faster transfer rates in real world applications. If you use a SATA harddrive, even way beyond the USB2.0 limit.
Now, about you're actual questions: There is tweaking you can do. The easiest would be to overclock the CPU by doing:
echo 1200000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
(this would overclock it to 1.2GHz)
It depends a little bit on the kernel version you use, but since you're positng in the Bananian forum, I assume it's kernel 3.4.x. If you use a newer mainline kernel, then there's more to it. You would have to edit the device tree file before compiling because the maximum frequency is hardcoded there.
As for RAM: To my knowledge the kernel or Linux don't set the RAM frequency but the bootloader (U-Boot) does. If you are on the old 3.4.x kernel you could change that maybe by editing the fex file or you would have to edit the U-Boot source before compilation (with mainline U-Boot you would certainly have to do that in order to change the DRAM frequency). That being said, I never tried this. And I still think you're going at it from the wrong angle. If you have 30 years programming experience, then you better report tests that have actual meaning for real world applications (not cached reads) and ask how you can tweak that.