-- HyperTransport question in regard to overclocking --

[Battlewaffle]

When you look at a sales description of the Athlon 3800+ (Venice core), it says "system bus 2000". Are they talking about a HyperTransport frequency of 2000mhz?

The default frequency is 200mhz, and using the HyperT multipliers in the bios, like for instance on the DFI lanparty Ultra-D board, it says it has dividers ranging up to 5x.
5x would put it at 1000mhz which is what I hear that you want to get it at, or close to.

So where does this 2000 system bus thing come into play. All I ever see is 1000mhz.

And in regard to people OC'ing. I'm trying to run an FSB of 234mhz (Venice core, 12x multiplier on a 3800+ puts that at 2.8ghz). So if I'm runnin 234mhz FSB, I assume I can't run 5x Hypertrans because that would put it at 1170. It won't run at 1170 I assume. So I don't understand how everyone is overclocking unless they run 4x multiplier.

My main confusion, is I don't understand what this "2000 system bus" is talking about like in this link: http://www.monarchcomputer.com/Merchant...roduct_Code=120208&Category_Code=AMD64

 

[Battlewaffle]

I'm guessing, and let me know if I'm right, that the HT frequency is 1000mhz true, but sorta how DDR memory works, it actually has a total theorhetical bandwidth of 2000mhz?

Sorta how DDR400 memory is not really 400mhz, but 200mhz. That's my guess on this whole HyperTransport 2000 MT/s thing. Am I correct?

 

[Concillian]

Not correct.

Marketing genius math:
1000 MHz X 2 directions = 2000 MHz

Not that it really matters much. With no direct memory --> CPU info passing through the HT, it could just as easily be 2x or 5x and get the same actual performance. The information passed through the bus is WAY less without the memory information that is passed through the Intel FSB.

 

[Battlewaffle]

So you're saying because of the AMD's internal memory controller, that the HT information isn't a whole lot. So the HT frequency doesn't matter too much on the total performance?

Isn't Hypertransport the communications conduit between the CPU and the chipset? (nF4 ultra in this case). Doesn't the vid card (PCIe information run through HT as well?) If so, I would think that communications running at 2x or 4x would make a decent difference between the CPU and chipset.

Sorry if I have this all wrong, I'm trying to understand Hypertransport and appreciate your patience.

 

[Concillian]

That is indeed what I'm saying. HT frequency doesn't matter all that much. It was a fairly widespread theory for a while. Then someone tested it... the data seems to support the theory:
http://www.neoseeker.com/Articles/Hardware/Guides/athlon64oc/2.html

Basically everone overclocking significantly is using a 3x or 4x multiplier on the HTT. There is simply no reason to push the Hypertransport speed, so dont. Keep it in a range where it is very stable.