Calculating Video Card bus requirements

[visivan]

I'm in the position of having to purchase a new video card for a PC with only a PCIe x16 slot available. I'm looking to buy a mid range card, maybe an HD4850 at most, but I don't want to buy more card then the slot can handle.

So what's the rough formula for determining how much bus transfer a card will require?

 

[Ares202]

PCI-E x16 is fine im running a 4870 on the same design

i read that you gain about 5% fps with a GTX280, so its not an issue at all you should be more worried about if your cpu and other hardware are up to the task

 

[visivan]

Great to hear. Rest of the system is a quad core 2.4 bumped up to 3.0 with 6 gigs on Vista 64.

I'd still be curious as to how to calculate it though if anyone knows.

 

[BlueAcolyte]

Well, PCI-E slots are measured in lanes up to 16.
PCI-E 2.0 has 2x the bandwidth (PCI-E 2.0 8x = PCI-E 1.1 16x)

I think each lane does 150 mbps, right? I could easily be wrong on the last fact. But any x16 is enough for any card currently.

 

[visivan]

PCI-E 1.0 has .25 GByte/s per lane up to 16 lanes and PCI-E 2.0 has 0.5 GByte/s per lane.