What does a chipset on a motherboard do?

[alternate]

The http://www.newegg.com/Product/Product.asp?Item=N82E16813128024 motherboard has an onboard video chipset called Intel GMA X3000. What is the Intel GMA X3000? Also, it has northbridge and southbridge chipsets called Intel G965 Express and Intel ICH8, respectively. What are these, respectively?

If one gets a separate video card such as the http://www.newegg.com/Product/Product.asp?Item=N82E16814130073 , then are the above onboard chipsets to sit idly?

I apologize if these questions are obvious. I would like to hear from somebody, though. Aregato!

[pentachris]

The video chipset is basically an onboard video card. Instead of buying a video card, you can use this "built in" video solution. If you were to buy a separate video card, this would "sit idly" as you said.

The northbridge and southbridge chipsets, in a nutshell, allow all of the PC's components, including some of the components on the motherboard, to talk to each other. They are what coordinates the communication between various parts of the PC. They will never sit idly, no matter what else you add to your system.

[SufferWell1396]

They also control how much RAM you can add, i think they might even have bus control, like what buses you can have on your system (ISA, PCI, PCI-E, AGP, ect..) but that may be the BIOS, im not sure...

[jlreich]

Also keep in mind onboard video is not true video card really. And although they have made great strides on the last couple of years they are not good for gaming. And onboard video borrows ram from the system and uses up quite a bit of cpu time taking away from overall system performance. This is why even a mediocre dedicated video card will always be better than the best onboard video.

[pentachris]

They also control how much RAM you can add, i think they might even have bus control, like what buses you can have on your system (ISA, PCI, PCI-E, AGP, ect..) but that may be the BIOS, im not sure...

The north- and southbridge chipsets do determine how much RAM you can have, what kind of CPU you can have, what sorts of buses the motherboard can have, etc. They do that ALONG WITH the BIOS - the BIOS is kind of like the operating system (or perhaps more accurately, the firmware) for the chipsets - chipsets without a BIOS are useless, and a BIOS without a chipset to operate is useless; they are indelibly tied together.

While we're at it, all motherboards have a northbridge chipset, but not all motherboards have a southbridge chipset. Or perhaps I should say that not all chipsets require a north- and southbridge. The ECS K7S5A, for example, was (is) a very popular motherboard that used (uses) the SiS 735 chipset. That chipset combined the traditional duties of the southbridge chipset (PCI, ISA & IDE bus control, integrated sound, etc.) into the northbridge chipset, and did away with the southbridge altogether.