Thanks, so a 4800 (Wich I'm not going to get) is the equivalent of a 4.8 Ghz intel (wich hasn't been invented yet)
You have to realize, the AMD naming scheme was never truly meant to say "it's equivilent to an intel running at xxxx" or "it's equivilent to a CPU running at xxxxGhz." It's really just a relative naming scheme. It is true that back when they first starting using it with the AthlonXP series, they were roughly equal to the Intel CPUs of that clock speed. But as speeds have increased, the comparison really becomes less and less valid. By now Intel has hit the thermal wall, meaning that their CPUs are producing such massive amounts of heat that they just can't push the clock speed any higher. So they've realized that they'll have to find ways to improve their CPUs without simply going for clock speed.. and have switched to a naming system, rather than Mhz rating (though theirs is horrible).
The reason that processor is a 4800 is because it is a dualcore. AMD seems to rate the dualcores by doubling the clock speed (since it has two cores, obviously), then subtracting 200 from the rating if the CPU has 512KB L2 cache per core, instead of 1MB.
For example, my 4400 is running at a clock of 2200Mhz, and has 1MB L2 per core, so it gets the 4400 rating. There's another version with a 2200Mhz clock but only 512KB L2 per core, which is the 4200. If you haven't figured out by now, that 4800 runs at a 2400Mhz clock, with a 1MB L2 per core.
So how does it perform? Really the only thing to do is look at benchmarks. The 4800 generally rates right between the Athlon FX-55 and FX-57, which are high end single core CPUs running at 2.6 and 2.8Ghz, respectively. I would personally call it the best CPU that money can buy at this time, as it is only a bit behind the FX-57, is $200 cheaper, and will flatten the FX-57 when you start introducing multitasking.