Question about PCIe ver. 2 and PCIe x16

[lostnfound53]

I built a computer back in April 2007 and am looking to upgrade to a current gen video card. I've noticed that all the new cards are specced for PCIe ver. 2 but are backwards compatible with boards that are only capable of PCIe x16. The particular board I have is the Gigabyte GA-965P-DS3. Now, my question is - how much throughput will be lost by not having a PCIe ver. 2 capable board? Is it worth it to even upgrade (using my current mobo)? I current use a 7900GS 256MB. The card I am looking at is the Radeon 4870 1GB.

 

[error8]

It's not worth to upgrade the mobo for a 4870 1 gb. The performance hit is very small.

 

[lostnfound53]

By very small, do you mean in the range of 1% to 5% versus a current mobo? I was afraid that it would be something like 50%. I've tried looking for information but there doesn't seem to be any articles related to this particular question.

 

[error8]

If you do a deep search in these forums, you will find a similar thread like yours and there was posted a link to a review that tested exactly one 4870 1gb in a pci express 1.1 versus 2.0. Usually the performance hit is around 5 % but there were some games and settings where it grew to 20% almost, if I'm not mistaken. I would search that review for you, but I'm too lazy to do it.

 

[nonameo]

it affects SLI/xfire much much more

 

[lostnfound53]

Thanks for the info, folks. Looks like I'm in for one, whenever a good deal comes up.

 

[Wonda I3oy]

I have read on numerous forums that an 8800GTX (which is no slouch) does not even use the full bandwidth of PCIx16....TBH I have a Asus P5K mobo with the PCIx16 slot and I have no probs running my GTX295....in fact I am getting very very good FPS in all the latest games. So dont worry about it...you are more likely to have a CPU bottleneck then the PCI bottleneck.

 

[biostud]

PCIe x16 has the the same bandwidth as PCIe 2.0 8x, so there's absolutely no reason to change your motherboard. Check out these charts PCIe v1.1 vs 2.0 ~3% difference:

http://www.tomshardware.com/re...ci-express,2095-7.html

 

[betasub]

This question seems to appear most weeks...

Maybe a sticky with a link to apoppin's thread & benchmarks would deal with this.

 

[garritynet]

I thought the real difference between PCIe 1.1/2.0 was the amount of power that can be drawn from the slot.

 

[Denithor]

chizow gave a very informative answer to this very question over here.

Really only affects CF/SLI setups, the PCIe 1.0/1.1 x16 bandwidth is adequate for any single GPU card available today.

And garritynet has a valid point also - the new 2.0 standard provides twice the power through the slot, reducing the amount the card has to pull through external wires. So be careful which card you grab - the new 9800GTX+ for example only has one 6-pin plug but they're counting on the bulk of the power coming through a PCIe 2.0 slot.

 

[habbakuk87]

Originally posted by: betasub
This question seems to appear most weeks...

Maybe a sticky with a link to apoppin's thread & benchmarks would deal with this.

:thumbsup: