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Crossfire on a p35 chipset.

T

TheSmJ

2[H]4U
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Dec 20, 2006
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I was planning on getting a couple 5850s to crossfire once the 6x00 series comes out (and the price drops), but I just realized the second PCIe X16 slot is only x4 electrically.

Benchmarks from 2007-8 show the performance loss to be about 5%, which is acceptable, but these tests were running 2x00 series cards. I'd imagine the results would look different using modern cards, but I can't find any benchmarks younger than 2 years old.

Has anyone tried this using the 5000 series cards? How much of a hit would I be taking due to the reduced bandwidth of the second card?
 
I've been wondering about this as well. Two 6x00 series cards would be kick ass but my p35 chipset really limits me.
 
I have a Dfi P35 on one of my side pc's put my crossfire setup on there . . . ran like a breeze p35 is still one of the fastest intel boards for 775 clock for clock . . . P45 just did better with quads ,
 
Two things that will hold you back.

You'd be limited to 4x on the 2nd slot max. Compounded by the fact that P35 is going to have PCI-E version 1.1 slots. That means that 2nd slot would be the equivalent of a 2x slot on a modern board with PCI-E 2.0 slots.

You would probably still see a performance increase over a single card but it would definitely be holding you back.
 
I figured there would be some kind of performance decrease,but the question is how much of a decrease would there be?

In other words, would it be worth getting a CF setup for $500 (two 5850s), or would I be better off getting a single fast card for $450 (a single GTX 480)?
 
um not much at all.. go on the front page.. click menu, go to gpu and find the reviews that kyle did showing the performance difference between 16x/16x 8x/8x and 4x/4x there was little no difference until you get into eyefinity resolutions..
 
sirmonkey1985 said:
um not much at all.. go on the front page.. click menu, go to gpu and find the reviews that kyle did showing the performance difference between 16x/16x 8x/8x and 4x/4x there was little no difference until you get into eyefinity resolutions..
Click to expand...

But those tests were done with PCI-E 2.0.

PCI-E 2.0 x4 is roughly equal to PCI-E 1.1 x8 speeds. The P35 never had PCI-E 2.0.
 
Danny Bui said:
But those tests were done with PCI-E 2.0.

PCI-E 2.0 x4 is roughly equal to PCI-E 1.1 x8 speeds. The P35 never had PCI-E 2.0.
Click to expand...

Agreed. Earlier this year I considered going Crossfire with my P5K, but PCI-E 1.1 and a 4x slot is just asking for trouble on modern cards. There was no bottleneck with cards available when P35 was released but now it's 2010 and things are different.


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OP I'd suggest sticking to a single GPU setup. For CF/SLI a new build would be a better idea.
 
Yeah, its a bummer because I was looking forward to my first multi-GPU setup.

I suppose the 5970 is still an option though, hmm?
 
Here is yours answer people.

Crossfire on a P35 chipset doesn't work. I had two 4850s on my ABIt IP35 Pro and I actually get lower frames with it enabled over a single 4850. WIth PCIe 1.1 slots at 16x/4x there simply isn't enough bandwidth for modern games to work. It worked great on older games.

I don't see a need to upgrade my whole system so I'm just going to get the a best single card I can get when the 6000 series launches next month.
 
Even if it would work it would be almost a complete waste. Nevermind the fact that you're PCIe bandwidth is severly limited, even if it wasn't, I don't see much point in pairing two 6k series cards on a Core 2 based system anyway.
 
Now I'm trying to decide if it would be worth buying a P45-based board and DDR3 memory along with a video card (or pair of cards). I can handle loosing 5 FPS because of the CPU at this point.
 
Yip P35 is a bad choice of CF, tried it on my MSI P35 board with 2 4870's and performance was not up to it, upgraded to Core i7 and then CF really worked well.
 
After thinking about it for a while I too agree its not worth spending the money on the old platform.

I'm -just- getting by with the 8800. I plan on playing Crysis 2 when it comes out early next year, and I plan on playing Metro 2033 after I upgrade. I play games with my monitor's 1920x1200 rez, and I like eye candy a whole lot.

Now I'm wondering if the PCIe 16X 1.1 slot would be enough for a modern video card. I was hoping to get one more video card upgrade out of this system before I upgrade the mobo/RAM/CPU the year after next.
 
Everything I've read about it suggests that current gen video cards will do just fine on effectively an 8x connection. I forget the URL of the test I'm thinking of, but a bunch of modern games (reasonably modern---I think they went all the way back to HL2 or some other Source game) were tested with the video card's PCIe connections taped off to 8x, 4x, 2x, and 1x speeds; and on most of the graphs you only saw noticable deterioration when you got into 4x speeds.
 
Cool. In that case I'll get the next flagship single-GPU 6K series card, assuming its faster than the GTX 480. :D
 
My Core 2 Quad is still very much relavant. I think even a good C2D is still a very capable CPU with todays games. My advice would be to get a high end single card solution for now which will give you better performance than simply dropping your current card into an i7 rig. In a year or two put together your a rig and move your single card to it and maybe pickup a second at that time for SLI/Crossfire. That is my plan. I just don't see a need to upgrade CPU/RAM/Mobo right now. It is more cost effective to get a single slot card now and upgrade everything else when it will give me more bang for my buck.
 
strikerP4 said:
My Core 2 Quad is still very much relavant. I think even a good C2D is still a very capable CPU with todays games. My advice would be to get a high end single card solution for now which will give you better performance than simply dropping your current card into an i7 rig. In a year or two put together your a rig and move your single card to it and maybe pickup a second at that time for SLI/Crossfire. That is my plan. I just don't see a need to upgrade CPU/RAM/Mobo right now. It is more cost effective to get a single slot card now and upgrade everything else when it will give me more bang for my buck.
Click to expand...

^ That's my plan. Just have to wait and see what AMD comes out with this month.
 
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