This issue was addressed in the Intel models of Mac Mini by using two notebook DIMM slots. Not supported in iOS 5 and later though. Combine this with the fact that Apple forces you to use the touchscreen (lack of Bluetooth HID profiles for mouse and joystick), this problem is not going away if you enjoy high definition graphics. Anyway, the iMac only has a 4850, which is a quarter of the raw graphics power of a dual 5850 setup.
For example, hw.cpufrequency from «sysctl -a» command reveals 0 when run on a jailbroken iPhone 4. Note that you can increase the CPU clock frequency, and thus increase the speed of the processor. The new iMacs are lovely but… they have glossy screens with no option of having, even to special order, a matte display. Apple also disables Bluetooth peripherals made by other companies (for example, the Sony Wireless Keypad is not supported at all. Press both Power and Home buttons and release immediately: Snap photo of current LCD screen and put into photo collection. This is to prevent people from buying cheaper cables and accessories. The smallest can probably circle a tiny house. On average, it can circle an apartment complex.
This software is what controls the baseband chip to communicate with the cell towers, and thus allow you to use cell 2G and 3G functionality on your device. Since the integrated graphics processor does not have its own dedicated memory, the system shares some of the main system memory with it. From a features perspective, the two have some important differences, and the balance doesn’t look great for Apple.