[moozer]

Hi

Would I be right in saying the 2x, 4x, etc that we see associated with AGP graphics cards is the speed and that only the speed will be affected if say I used an 8x AGP card in a 4x slot. I mean would that affect the actual performance of the machine it's on?

 

[kiwiguy]

Only the video performance to the ability of the card, assuming the card is compatable in the first place with the motherboard.

It would not slow the bus down, if that was your question.

 

[moozer]

Thanks for the reply. I'm looking for a new graphics card and wondered what would be the best available to me. I'm looking at least for 128MB and I'm using AGP 4x or PCI. I have an old system, but it suits my needs at present and I don't use the PC for major gameplay. It seems that anything from 256MB uses 8x, so that was the point of my post - could I still use an 8x on a 4x port without serious degradation of performance.

 

[moozer]

I have another question - in BIOS there is an option for AGP aperture size. Does this setting relate to the graphics card memory? If so, do you need to set it in relation to the card? e.g. if I use an 16MB card do I need to set aperture in BIOS to 16MB?

 

[JohnWill]

Leave the AGP aperture size at the BIOS default unless you have some specific reason for changing it. Google is your friend. http://www.techpowerup.com/articles/overclocking/vidcard/43

 

[Jones]

I seem to recall there being an issue with the voltages between 8x cards and 4x cards.

Here's some info on slot types and compatibility:
http://en.wikipedia.org/wiki/Accelerated_Graphics_Port

 

[kiwiguy]

I seem to recall there being an issue with the voltages between 8x cards and 4x cards.

Exactly, hence my recommendation regarding motherboard compatability.

 

[moozer]

Kiwiguy, I get conflicting opinions here and there:- some say not compatible, some say 8x can be used on 4x but performance is reduced. My mobo manual tells my simply the AGP slot is 1x, 2x and 4x, so I would assume that I'd be better off sticking with the 4x option.

 

[Rich-M]

I think what you remember here is the newer 1.5 volt card vs the older 3,3 volt and that concerns 2X cards where you should not put a 1.5 volt card into a 3.3 slot.

 

[moozer]

My mobo supports AGP 66 / 133 MHz, 3.3V/1.5V

 

[Skivvywaver]

If you have a 4x board then yes you can put an 8x card in it without a major performance hit on the card.

If you have a 2x board, you can't use an 8x card. For one thing the slot isn't even keyed for an 8x and for another the voltage of a 2x would fry the card. In other words, if you can get the card into the slot without a hammer, you can use it.

4X

2X

 

[moozer]

Thanks Skivvywaver
;-)

 

[Courtneyc]

By the way, the 4x / 8x affects sidebanding, not the speed of the card. Sidebanding is where the graphics card can store textures used in, say, a game. The aperture is where they are stored. I don't actually recall any games that actually used this ability. Certainly, none of the newer games use it. PCIe doesn't have this ability. (But it does have something similar--Google for "HyperMemory".)

Courtney sends....