Routerboard.com says that both the RB450G and the RB750G use the Atheros 7161, ie:
.....RB450G: http://www.routerboard.com/index.php?showProduct=52
.....RB750G: http://www.routerboard.com/index.php?showProduct=90

The MikrtoTik wiki's Switch Chip Features page says both these devices use an Atheros 8316.
.....http://wiki.mikrotik.com/wiki/Switch_Chip_Features

Anyone know which one is correct ?

If the wiki needs a correction, could someone please update the wiki ?

where is the problem exactly? there is no contradiction. the specs sheet says that they both use the same CPU, which is correct. the wiki says they both use the same switch chip, which is also correct.

I see no problem

where is the problem exactly? there is no contradiction. the specs sheet says that they both use the same CPU, which is correct. the wiki says they both use the same switch chip, which is also correct.

I see no problem

Thanks for this. I mistook the switch chip version for the cpu version.

According to this page: http://wiki.mikrotik.com/wiki/Manual:Sw ... p_Features , it appears that RB450G has ether1 LAN port independent on the switch chip, which not the case for RB750G. The advantage is higher troughtput from switch (ether2-5) to ether1 port on RB450G in routing or bridging mode.