Bus question...

[omniphil]

How if any will the bus speed (and/or ram speed) effect at what limit i can download stuff from the internet via a network card that is plugged into the bus obviously.

I know this sounds strange, but I have a friend at work that thinks the bus speed of the computer effects the download speed of data across a lan. And I think it is not true, I think the network card has a limit that it will reach reguardless of the bus speed because the bus speed is way beyond the netcard speed.

Basically he see's the kb/sec download speeds and he thinks this is directly related to the bus speed which is in mhz. they dont seem related to me...

What do ya think?

 

[thorin]

It's completely unrelated.

If you could find a PCI card that was capable of accepting a incoming connection at a higher transfer speed then the PCI bus (133MB/sec) could handle then it would have to contain it's own huge buffer for the information. ie: If there was such thing as a OC-96 PCI card or something like that (which there isn't). Remember even GigaBit ethernet can only max at 125MB/Sec .

The speed of your PCI bus is determined by a fractional multiplier of your FSB, if it is out of range then PCI devices start failing.

Thorin

 

[omniphil]

Can you give any details? I mean the network card does actually communicate thru the bus, but i would think the bus speeds are way higher even in an old 66mhz bus than any network card.

 

[Jeff7]

Originally posted by: omniphil
How if any will the bus speed (and/or ram speed) effect at what limit i can download stuff from the internet via a network card that is plugged into the bus obviously.

I know this sounds strange, but I have a friend at work that thinks the bus speed of the computer effects the download speed of data across a lan. And I think it is not true, I think the network card has a limit that it will reach reguardless of the bus speed because the bus speed is way beyond the netcard speed.

Basically he see's the kb/sec download speeds and he thinks this is directly related to the bus speed which is in mhz. they dont seem related to me...

What do ya think?

Unless you've got 100 Megabit Internet service, you're not going to be taxing your network card anytime soon.

So yes, "completely unrelated" is definitely the best, simplest answer.


A slightly more detailed explanation:
The network card resides on the PCI bus, which operates at 33Mhz, and has a maximum speed of 133MB (megabytes) per second. The network card is rated at 100Mbps (megabits per second), which translates to a theoretical maximum of 12.5MB/sec. So even that is nowhere near the speed of the PCI bus. And it's doubtful that you're going to find 100megabit Internet service anywhere nearby, unless you have many thousands of dollars to spend on an OC-3 connection.
There's also bus speed in terms of the chipset, which is faster. These days, it operates at an effective speed of anywhere from 333MHz (166Mhz, double data rate), up to 1066MHz (533MHz, DDR) for the new Pentium4 boards. Those have througputs in the multiple-GB/sec range.

Higher bus speed will make the system more responsive, as the CPU, memory, and chipset can all communicate faster, but this won't speed up your downloads, at least not until we have Internet speeds that are in the multiple gigabyte/second range. And by that time, computers will be inexplicably more powerful than anything in existence today.




I don't know why, but why do I think Intel's marketing department is partially to blame for this? "Accelerate your Internet Experience" or something like that....when CPU speed has no bearing on Internet speed, that is, assuming you don't have a 20MHz 286.

 

[omniphil]

But let say your using a local lan, can the lan speed exceed the bus speed on $10 network card?

And a gigabit card maxing out at 125mb/sec, can that data rate be effected by bus speeds limitations? i mean some of these new motherboards have like 2000mhz bus's? vs the older 66mhz bus's?

lol, im confused

 

[thorin]

The Bus speed of the processor has no effect on the bus speed of the peripherals.

Thorin