16x PCI-e vs 8x PCI-e in CrossFire/SLI (The Answer..)

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Andz, very informative,NICE!

this is helpful when you are benching and at least you will have a good starting to point in predicting where the bottle neck might going to occur. Saves a lot of time and frustration Thanks for the effort and time for the thorough research for everyone's benifit.

dili pa kaayo ni relevant nga comparison kay none of the cards available today can fully make use of PCIE 2.0. but thanks for answering these questions.

Polds, is there a software or some sort that will measure how much a graphics card is using per given lane? I'm just wondering if 2 cards that are sharing a 16x lane (8x + 8X) will be fully utilizing it or under utilizing it during Crysis/Vantage benchmark, would really love to see that number compared what's on the paper

[andz]

It depends on the gaming engine and the video cards.

for example:

Running 3x 4870 playing Call of Duty 4 would have huge improvement. but playing crysis the 3rd 4870 will not benefit at all or little. but the 3x 285 would have huge benefit in crysis, but not so good with Call of Duty 4.

2x gpu's with a good engine should fully utilize 8x-8x lanes. but it will start to bottleneck if you exceed the data rate.

Depends also on the software you are using.. Vantage doesn't use havoc engine it uses Phys-X engine. They should make a Vantage 2 and add Havoc in it to make it fair. That's why lots still use 3dmark's 06 then vantage.

ATI might have the best hardware, but they don't have good drivers.
Nvidia might not have best hardware, but they have better drivers.

[poldopunk]

as far as i know, wala man software bai kay when we say lanes, physical lanes man gud na sa board. pero hardware, nag google pa ko.

nosebleed sa ta tanan o, dugay nako sige tutok ani, wa pa nako ma absorb ang article

http://download.intel.com/technology...s/pipe2_00.pdf

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just curious lang to see the numbers on windows I guess the only way to tell a bottleneck if you notice a drop in frames/scores as you go faster.

andz, lols I am happy that there is 3Dvantage for my 295's but I would be un happy if there is no benchmark software to utilize it. Can't complain

[andz]

just curious lang to see the numbers on windows I guess the only way to tell a bottleneck if you notice a drop in frames/scores as you go faster.

indeed haha ana jd ni..

poldopunk: Nosebleed bleed reading that wahhhhhhh

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polds, walay for "dummys" version ana? hehe

[Kenshiro]

It depends on the resolution. May have little difference if resolutions are very high.

[andz]

It depends on the resolution. May have little difference if resolutions are very high.

please read the whole post, there is no difference with any resolution, it will not bottleneck any of those cards at higher resolution.

The only exception would be the 4870 X2 and GTX 285 X2 if ran at 8x. At any resolution this two will bottleneck.

This was already tested in overclock forum:

Crysis:
2x GTX 295 @ 16x-16x slot PCI-e 2.0 - 2500 x 1600 resolution = 16-20 fps
2x GTX 295 @ 16x-8x slot PCI-e 2.0 - 2500 x 1600 resolution = 16-20 fps

[jhnpl]

pls correct me if I am wrong.
Does this mean nga ang ako DFI LanParty JR P45-T2RS (8x/lane) running on 2 x 4850 xfired ok ra?

thank you!

[andz]

pls correct me if I am wrong.
Does this mean nga ang ako DFI LanParty JR P45-T2RS (8x/lane) running on 2 x 4850 xfired ok ra?

thank you!

yes basta 2.0 PCI-E slot.

HD 4850 = 993mhz (dual piped - 1.9 GB/s data rate) = 1.9 GB/s total data rate
HD 4850 X2 = 993mhz (dual piped - 1.9 GB/s data rate)(times 2) = 3.8 GB/s total data rate

8x - 1.9 GB/s ~ HD 4850
8x - 1.9 GB/s ~ HD 4850

8x - 3.8 GB/s ~ HD 4850x2
8x - 3.8 GB/s ~ HD 4850x2

PCI-e 2.0 16X = 8GB/s total bandwidth
PCI-e 2.0 8X = 4GB/s total bandwidth

Centax_error: ahhaha of course, nvidia raba higher score the better!