a processor question

my question is,does dual or quad core processors speeds measured separately or alltogether?
foe example the game asks for 3.2 Ghz CPU...
so if i have 2.8 Ghz Dual core,is it 2.8 alltogether?or 2.8 each core and do they function as 4.6 Ghz or do they let you run many programs at the same time by working separate from each other?

Thanks,hope you understand the question

Originally posted by Pavel ...foe example the game asks for 3.2 Ghz CPU...so if i have 2.8 Ghz Dual core...

Another factor is what internal architecture the CPU uses. This effects how many instruction per clock it executes -- IOW how much work at a given clock speed.

E.g, older Intel Penium IV chips had relatively poor instructions per clock. The new i7 has good instructions per clock. I don't know the exact difference, but the i7 might do 50% more work at a given frequency, maybe more.

So an i7 at (say) 2.8Ghz might be doing more work than a Pentium IV at 3.3Ghz.

Re can you add the CPU frequencies of each core -- generally no. Games especially are often single-threaded, which means they run on a single core.

There's a tendency think "I'm only playing a game, everything else is shut down". But it takes a lot of processes and threads to do network I/O, disk I/O, and just keep the OS running.

If you look in task manager you'll see many processes. Then do view | select columns, and add "thread count" as a column. You'll see a huge number of threads. Most of those are not runnable -- they're waiting on some event. But many are runnable, just waiting for a CPU. With a single core CPU, all those must contend for the single core, thus slowing down your main activity. With multiple cores some of those threads can run elsewhere.

So while a single-threaded game *itself* cannot use multiple cores, that game doesn't run in isolation. It requires an operating system under it, which itself has many processes and threads, all of which are contending for CPU resources with the game. That's where multiple cores can help.