diff between nforce4, ultra, and sli

[Viper_7]

This is probably a newbie question but can somebody explain to me the difference between an nForce4, nForce4 ultra, and an nForce4 SLI? Also, what's the difference between a PCI-E X16 and a PCI-E X1 other than the size? I know the video cards go in the X16, but what goes in the X1? Thanks for all your help.

 

[Viper_7]

I also had another question. What does it mean when the fsb for a socket 939 motherboard is 2000 MT/s? This is what the Asus A8N-SLI Deluxe says. I know the memory controller is onboard the processor, but can somebody clarify all this for me please. Thanks again for your help.

 

[Crashman]

Aha! OK, X16 is for graphics cards and X1 is for everything else. X16 replaces AGP and X1 replaces the old PCI slots. X1 is nearly twice as fast as the old PCI standard in each direction, and it's full-duplex (doesn't have to share upstream with downstream). PCI was getting slow, so x1 is a great improvement.

SLI is how nVidia allows you to have 2 x16 slots operate in x8 mode, so that two graphics cards can be used simultaniously. nVidia allows 2 modes in SLI to improve performance, split screen or striped, with one card doing one half and the other card doing the other half.

So the SLI chipset comes on a board that has 2 x16 slots, if both are used each card gets 8 pathways instead of 16, and you can get a performance increase from using 2 cards. You pay more for the board, and if you want to use that feature, you have to buy 2 expensive video cards.

AMD uses a HyperTransport bus between the chipset and CPU. Previously it was based on a 2x bus with a 4x data multiplier (800 transfers per second). Now it's based on a 200MHz bus with a 5x data multiplier (1000 transfers per second). And since it's also a full-duplex bus, it can do 1000 trasfers up and 1000 transfers down at the same time. It's like saying "This is a 140MPH freeway because the speed limit is 70MPH in each direction", but hey, the inflated numbers are good for advertizing.

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[tweebel]

The other advantage of PCI express 1x is that each bus has its own bandwidth to the nordbridge. All old PCI devices had to share the same bandwidth.

 

[sh1ft3d]

Damn Crash, you are good at explaining things and puttings thing into perspective. I didn't really know what that Hyper Transport thing really meant, but I now I have a pretty good understanding. If I understand completely, then the way it compares to what I have now (which is an AMD 1800+ with 266FSB) is that my current system with 266 FSB is actually two pipelines (or the 2X multiplier) of 133 so basically long story short, in terms of FSB, the new AMD procs coming out blows my system way out of the water.

 

[jammydodger]

actually two pipelines

Actually it simply sends data twice for everyclock cycle, but yeh you can think of it as 2 pipelines you get the same result.
The new Athlon64's/FX's arnt better than the XP purly because they have a faster FSB, it is better because they are more advanced CPU's.

 

[Viper_7]

Thanks for all of your responses. This has really helped in understanding.