Does anybody have idea how to overclock 7XX series ? We are getting on edge with its ability.. It passes only 180Mbits in TCP/IP while system ability is 230+Mbit in 40MHz.
/system routerboard settings print
/system routerboard settings set cpu-frequency=...
The webfig UI has a drop down with possible values. On the RB750G I’ve got handy it includes 400, 600, 680 and 800 along with several lower speeds. Check the web UI on yours to be sure what it will accept. Also be aware that overclocking the CPU may cause overheating and stability issues.
I mean over regular..
800MHz is over regular. There is no way to set it higher than that
Ok, but 800 would be OK.. 
There is now only 400MHz..
[admin@AirBQ Client] /system routerboard settings> set cpu-frequency=800
input does not match any value of cpu-frequency
I mean RB751G is excellent piece on hardware and everybody accounts on working range about 100-150Mbit max. As we are using clear sky, links are able go on its best and it becames very tired about trhuputs of 180Mbit (CPU 90percent) We clearly know that ceiling is 230Mbit with RB751, but matematicaly 245Mbit. If I would use 60MHz, it it will be nice client, but for AP there is no suiting HW.. Orrrrrrr, is there any foreview for more powerfull PRO HW?
It means that this model doesn’t have capability to work at 800MHz. Please see available options from the dropdown menu, like the other poster suggested.
We are looking for some IDDQD option or something like that.. 
I will post some pics to describe what I mean, and what it can mean for Mikrotikis in future..
RB411AH has the 800 option, RB700 series does not have capability to do that.
RB411AH is PCI design - it is slow.
depends on task you want it to perform.
Radio transmit.. we do transvertor stuff and maximum thruput is welcomed with 751G we can do this now, which is severe difference against jammed 5GHz and 2,5GHz. More robust platform is welcomed.
What normis said. Note that I checked the options for a RB750G, which has 680Mhz as the default clock speed (I actually underclock it most of the time because it’s not heavily loaded) and 800Mhz as an overclocking option (~15%), if your CPU has standard clock rate of 400Mhz then you probably shouldn’t expect more than about 480-500Mhz for an overclock, but check the pull down to see what it allows.
R751G doesn’t support any higher frequencies than it’s default 400 MHz. If you need higher performance, you can use RB411GL - yes, it has only PCI card, but is this a problem? PCI transfer limit is much higher than limit of the wireless card.