PCI Express 2.0 Backwards Compatiblity

[Mobius]

I'm looking at upgrading my video card from this: 8800GTX

And from what I'm seeing, everything these days is PCI Express 2.0, whereas my motherboard has only PCI Express 1.0 slots.

[Mazza]

It will run yes, but lower speed, dunno how much lower though :-/

[Wingo]

The transfer rate toth e card and back will be theoretically halved. This will be a bad bottleneck and would also limit the card's abilities. If you're buying a PCIe 2 card you will be throwing money away unless you get a PCIe 2 compatible motherboard

[NickN]

That is totally incorrect from a RW standpoint.. you are reading specs and assuming the data rate difference between the standards is in use today

What the card will lose is higher functions however it will not 1/2 the bandwidth

Data rate is different and there will be a loss there however the thing is there is no application USING the 2.0 data rate and therefore the loss is not 1/2.. just because the standard allows a 2.5 GT/s to 5 GT/s increase does not mean we have been actually using that!





To the OP: This is the deal... the 2.0 standard is backwards compatible however it depends on the motherboard and its BIOS how well the card may work on older systems.

First of all if your motherboard is 1.0 and not 1.1, etc then you can expect more issues than its probably worth unless your motherboard company has issued a BIOS update which assists.

The main problem is 2 areas.. first the 2.0 standard places more power at the slot itself which enables the higher functions of the cards. Without that power the higher functions of the 2.0 card will be neutered. 2nd is the BIOS code. Older 1.0 systems which are made from 2004-2005 will probably not run the card at all. Systems with the 1.1 standard produced after January 2007 should run the card fine assuming the motherboard manufacture has updated BIOS code in the system (May need a BIOS update) but with neutered results. It will not cut the card performance in 1/2 but there will be a loss none the less. There are some 1.1 boards that may not run the cards either.. as they were recycled from the 1.0 standard and do not have 100% 1.1 support.

I would need to know the exact make/model of the motherboard and in some cases the revision to know where you stand on that.



BTW.. PCie 3.0 is on its way later this year which means barods/cards will have it sometime in 2010

[Mobius]

Thanks for the responses guys.  It sounds like the new thing is right around the corner, so I should probably save the money for a much bigger upgrade.  Seems like that's always the case...