Graphics Card Ports On Motherboard?

How do graphics cards connect to the motherboard?

I've been quite cofused, reading the 2006 GPU guide, when he said that graphics cards have made the change from AGP to PCI express.

But I thought dedicated GPUs only used an MXM or AXIOM slot. I was even more confused, readng Chaz's Compal HEL80 review when the nVidia GeForce Go 7600 was connecting to the motherboard using a PCI express slot.

Am I getting confused with desktop GPUs? Why would nVidia cards use PCi-e when in the 2006 GPU guide, it says that nVidia's "standard" is MXM?

 

AGP and PCI-E refer to the port used in a desktop system.

Up until recently though, manufacturers have used smaller version's of these ports in laptops. MXM, however, refers to the form factor of the card in a laptop, be it type I, II, or III.

 

but why would you have a PCI express slot on a mobile motherboard for a mobile GPU?

....if PCI refers to ports used on a desktop system...?

 

PCI-E is on a laptop so that the motherboard and graphics card can communicate faster. It also helps manufacturers offer upgrades to consumers, as they can simply swap out a graphics card, in place of a different one. Bear in mind, however, only a few manufacturers can do this.

PCI (non Express) are on desktops, but PCI-E is mostly graphics optimised, therefore it can be sued in both laptop and desktop, because of its speed.

 

oh okay...so MXM and AXIOM are not actual ports on the motherboard, they just describe the kind of chip, right?

 

mxm and anxiom are just labels created by Nvidia and ATI for there specific implementation of pci-e on the mobile platform. They are both incompatable....yet do the same thing...which is to provide a high bandwidth gpu specific bridge....just like pci-e X16 is on the desktops. The initial idea was to allow gpu cards to be upgraded but this hasnt worked out.....for many reasons.
Also the reason why laptops have this is because the newer mobile gpus such as the X1600 is built around the pci-e interface, at least with ATI, they would then need to add a bridging chip to interface with the older AGP, like the do on a few desktop cards, but this increases costs and also space useage, something which there isnt alot of in a notebook.
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oh okay....thanks.

 

PCI-e and AGP are communication and connection standards. In notebooks, the manufacturer can do away with the slots/ports. So instead of having any actual physical 'cards' they can just solder the GPU and video ram onto the motherboard. An X1600 attached to the motherboard without a removable card is still a dedicated/discrete graphics card.

They can do the same thing with CPU's as well, the MacBook and MacBook Pro for instance, have their Core Duo chips permanently attached to the motherboard instead of using a socket. Same with ram in some ultraportables, some have a stick soldered on.

MXM and AXIOM are something else. They're both just module standards: MXM stands for Mobile PCI Express Module, and AXIOM for Advanced eXpress I/O Module. The communication standard they both use is PCI-e.

For desktop computers, the add-on cards for PCI-e, AGP and PCI are standardized, so for the most part any PCI card will fit in a PCI slot on any motherboard. This wasn't the case in notebooks, if the manufacturer was using an actual card for the video card, the card would be a unique shape and use a proprietary connector that only worked for that particular notebook. Both MXM and AXIOM try to introduce a standard so the connector would be the same, and cards would be in specific form factors allowing interchangability.

It hasn't really been all that successful I would say. I don't believe the OEM's are adopting, Dell for example still uses their proprietary modular cards and connectors.

 

ATI's AXIOM is largely dead; my Clevo M560A is the only notebook I know of that uses it.

ATI has actually started using MXM . . if that says anything.