Hence why you need an emulator
. And emulator would need much faster CPU than it is available today.
Actually no you wouldn't. a ps3 has 512mb in all of usable ram. there are no computers that are still sold with nearly that low amount of ram. standard now is 4gb, and processors are much faster too. the other person is right. ps3 is built on an arm processor, for which you would need an arm emulator. theese are hard to make. that is why there isnt an emulator, because people are too lay to make an emulator.
Its not that simple though. For example, you have to make all the low-level timings bus accurate. You have to emulate the Cells...unique memory management scheme. You have to deal with the overhead involved in the OS scheduler, rather then dispatching instructions directly to the CPU. All this combines to leech performance. And this is BEFORE you do a POWER7 to x86 conversion...
I mean, sheesh, the Gamecube has a ~400MHz processor, and the Dolphin emulator has SIGNIFICANT speed issues in several titles. Working off that, you realize why emulating a 7-core CPU @ 3.2GHz is quite impossible.
As a rule of thumb, it takes 10x the processing capacity to emulate a system in realtime.
That being said, there is a VERY early emulator that does little more then emulate the PS3 BIOS. Can't even boot the system menu yet though, and lacks audio and graphic support.