General Clock Speed Question

First of all, know that a couple weeks ago I didn’t know it was even possible to build a computer (other than the manufacturers), so my knowledge is very limited.

I’ve been looking into it but got stuck in one area: synchronizing the memory, buses, and processor. This is what I know so far (or think I know):

All the circuits must be synchronized based on the system clock in order for the computer to function optimally. The RAM and processor should be able to send and receive data at the same rates? Circuits that run at different speeds than the FSB use either a divider or a multiplier. This is OK for the CPU because it doesn’t have to send or receive data every clock cycle. But beyond this, I don’t understand much.

For example, what if I have:
AMD Athlon 64 X2 Dual Core at 2 GHz
A pair of 512 MB DDR2-800 RAM (for a total of 1 GB)
FSB at 1000 MHz
Dual Channel Memory

The processor’s multiplier would be 2? So 1000 MHz * 2 = 2 GHz. But then there are two cores sharing one FSB, right? So would the multiplier actually be 4? Also, aren’t Athlons double-pumped? Then each core would send and receive a signal twice a clock cycle. But how would that be since they are sharing a FSB? Then there is the RAM. DDR means double data rate, which would match the processor’s double pump, correct? And there is a pair of DDR2’s to utilize the dual channel, which would match the cpu’s dual core, but the DDR2 runs at 800 MHz, so how would they be able to send and receive data in a synchronous manner?

Anyway, can someone explain all this, or give an article or something explaining it.
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More about general clock speed question
  1. You dont have to worry about all that stuff. If the proccesor you are getting is socket 939 then you will need a socket 939 motherboard and DDR ram (not DDR2) at 400mhz. IF the proccesor you are getting is socket AM2 then you will need a socket AM2 motherboard and DDR2 ram the higher frequency the better. Everything will work as it should. Your making it a little more complicated than it really is.Hope this helps.
  2. Once you know what you want to get, post it here and if there are any compatability issues, someone will point them out.
  3. >>For example, what if I have:
    AMD Athlon 64 X2 Dual Core at 2 GHz
    A pair of 512 MB DDR2-800 RAM (for a total of 1 GB)
    FSB at 1000 MHz
    Dual Channel Memory <<

    You would have to get an AMD AM2 processor to run A pair of 512 MB DDR2 RAM-800. AMD Athlon 64 X2 Dual Core processors run on 939 MB's and use DDR RAM not DDR2.
  4. I don't think that CPU can use DDR2. You can go to Corsair and put in the mobo (mfg and model) and they'll tell you what memeroy is compatable for that mobo. I think Kingston might have a similar feature.
  5. I actually found the parts on newegg.
    In the specs it said the mobo supported ddr2 800 and had an am2 socket.
    The athlon 64 x2 comes in am2 and 939 on newegg.
  6. "AMD Athlon 64 X2 Dual Core at 2 GHz" should have been "AMD2 Athlon 64 X2 Dual Core at 2 GHz" The AMD2 will take DDR2 but the AMD won't. Sorry, didn't mean to mislead you.
  7. Most of the time, your computer will sort out all these speeds for you.
    The CPU has its voltage and multiplier requirements embedded in it.
    The ram has a small chip (SPD), I think it means serial presence detect, that has its voltage and speed requirements.
    The other parts/sockets have fixed speeds built into the mobo.
    Sometimes (rarely) when a computer will POST but is either unstable or will not boot you need to enter the BIOS setup routine to tweak specs. This is usually a memory issue. If you buy the right memory you will not have this problem.
    Once you pick out the motherboard, go to various memory mfrs websites to find out what's made to work with that board. Corsair, Crucial, Mushkin, Kingston and others all offer this feature.
    The CPU must match the motherboard's socket.
    The memory must match the motherboard's requirements.
    The videocard must match the motherboard's socket (today almost all are PCI-E).
    The power supply must be big enough to run the system without overheating.
    If you do this all will be well.
  8. OK Thanx all, I guess I was just overthinking things
  9. where on earth did you get amd2? the socket is am2, but the processor is still called amd a64 x2....
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