it is a chipset, it controls the communication between the hardware, it also contains a sata and ide controller along with a networking controller. it is just like an Intel 865 chipset and a sis chip set.
it is made by NVIDIA for AMD and Intel chips. was also used in the original Xbox for the chipset i think too
Yes, nForce is way better than VIA or SiS. Sorry via and sis fans, but somebody had to say it . I have had several via chipsets before and I never really had any problems with them...till I used an nFocre chipet. When I went from a VIA chipset to the nForce with my 3500+ my cpu went up!!!! I didnt do anything to it, it just went up. My old via board had a lack of RAM options and the OC options werent so great either. nForce is a feature rich chipset that helps everything run to its best . The other ones are "ok" but nForce is great
I went from a VIA Kt400 to NF2 and saw no improvement on a 32 BIT system. The big claim to fame for NF in 32 BIT systems was dual channel memory but I never saw any significant improvements with my Barton CPU even on a memory only benchmark.
I haven't gone 64 BIT yet so I don't know personally about the NF3 and NF4 performance vs the VIA and SIS. But when the NF3 and Kt800 first came out the KT800 was the prefered chip. That has since changed with chipset updates.
The benchmarks I've seen have shown no significant difference in performance between VIA and NFx. The SIS are usually a little slower. I seriously question performance going "way up" on any chipset change, especially on 64 BIT AMD where the CPU and Memory talk directly and the chipset just handles I/O.
The other thing they did not mention above is that an SIS MB is a lot cheaper than the VIA or NFx chips. So if your building systems for resale SIS is the way to go.
The other differences will be in number of USB/firewire ports, LAN type and quantity, support for dual video cards, etc.
Thinking about it. The reason I stopped running benchmarks on my own system was that I never saw any substantial improvements for any of the "hot new chipsets and features".
NF3 and 4 are 64 BIT. The NF3 is AGP and NF4 is SLI.
the main increase that i saw from going from a via to Nforce was in my memory bandwith. and i have seen an improvement in the render times of video becasue of it. other than that there is a little increase that i have noticed in games but not a whole lot. the big one for me was the render times. other than that there is a down side to the Nforce chipsets is that they do get hot when you use the 3 and 4. i dont rember about the NF2 but that is in my media center. i would have to agree with leejend about the bench marks. they will so an increase but for you to notice it may not happen.