Front side bus??

[Wobbit]

I bought a Athlon64 3400+(754) a while ago and it runs great... But, for the longest time I've been trying to figure out what the front side bus is. Everything I see says 'Intergrated into chip' and nothing more than that.

Here's my system specs:

Asus K8N-E Delux
Athlon64 3400+
512mb DDR400
200gb WD S-ATA

If anything could point me in the direction to find out it would be great, thanks.

 

[Gamingphreek]

he FSB is the speed at which the chips communicates with the memory and the memory controller. Since the memory controller is on the chip they try to tell you it is integrated.

Default should be 200 unless you are running with 4 sticks of memory.

-Kevin

 

[brazzmunk]

shouldn;t the FSB on a64's be something like (HT multi * HTT) or arround 1Ghz?

 

[Leper Messiah]

*sigh* OK, let me explain this to you. The Front Side Bus (FSB), doesn't truly exist anymore with an Athlon 64. The FSB was how fast the northbridge sent RAM data to the Processor. On an Athlon 64, the RAM controller is intergrated on the core, hence it operates at the full speed of the processor.

Now, there's something called the system clock, which, on an Athlon 64 is 200mhz. This is the clock where all the other componets get their speed, either by using a multiplier, a divider, or being locked in some way. Your RAM will run at this speed by default if you use a 1:1 divider for your RAM. Your processor uses the system clock times the muliplier (either 11x or 12x in your case, clawhammer vs. newcastle) to derive its processor speed. The Hyper Transport Tunnel (HTT) uses this, plus a mulitplier (1x to 5x)to derive its HTT speed. The HTT is a dedicated transport bus that carries AGP data to an from the processor (i believe. I'm not certain on that last part. I know that its dedicated though to something.)

The fact that the Athlon 64 doesn't have a FSB is why you can use a RAM divider without a performance hit, since no matter what, you're still using a divider of some sort. Say I use a system clock setting of 240, a 10x multi for my proc, and a 5:6 RAM divider (166mhz). CPU-ID will say that my RAM is running at processor speed/12, or exactly the same thing as a 3700+!

 

[Calin]

The memory bus runs at 200MHz DDR, or at 166MHz DDR (depends of quantity of memory, and other things). However, the communication between the processor and the rest of the system is made thru the HyperTransport bus, and its speed is either 800MHz or 1GHz. The processor speed is generated as HyperTransport speed multiplied with the HTmultiplier