I am considering picking up another 3870 this Friday ( to make it 3 total) I have been hearing things from technician friends of mine who also gamers that adding another video card only would give you ~15% performance increase and little overall change to your benchmark.

does anyone have experience with running more than two video cards - if so, what if any were the performance changes?

Just wondering if its actually worth it. Also on a side note - is one 4870 = 2x 3870's ?

Depends on the inviduals use as well.

Alot of programs dont utilize Xfire/SLI thus a single GPU would benifit more.

So I would prefer a 4870 over 2x 3870's

Or a 285 or 280.


Hope this helps.

Brian

I'm going to continue on this as I was in a rush doing some banking and setting up going to an auction tuesday.

Also if anyone wants to come to an Auction Tuesday lemme know as I am 75% sure at the moment I can book it in. There are 125 vehicles going with no reserve in dartmouth at auctionad. IF anyone is as bored as I am.

Onto the Single GPU vs. Dual.

With multiple screens and you wish to play in windowed mode to scroll across your multiple screens crossfire or SLI will not be available to you and you will be wasting that one extra GPUs potential as well. Also just not too many games still utilize it.

Have I utilized SLI and crossfire? Yes

Will I anymore? Probably not.


But from the rumor mill. I do recall Nvidia having drivers coming out that will support SLI on multiple screens. I could be wrong and would appreciate if anyone could let us know.

Cheers


Brian

Thanks for the info and the prompt reply.

Now for you're question, its in the works, yes.

http://news.softpedia.com/news/Nvidia-F ... 1425.shtml

For the most part 2x3870's are faster than a single 4870. However if it's a 1GB 4870 it's going to have the advantage in games with detailed textures and use shaders quite a bit. A third card is hit and miss depending on the game. I'd look at a single GPU solution like the 4890 or GTX285 or wait till the end of the summer when the new goodies should arrive.

i use the 4890 in my worksattion and its a solid card, especially with the core clocked to 1ghz, but i still see better performance with the dual 4770's in my HTPC for about 90% of games. that being the case i reccomend 2 4770's for around $200, if you can find them right now. the gtx 275 is also a very nice choice right now.

Seeing that I am using a Crossfire based platform (up to 4 cards supported) I will have to stick with ATI. I was originally asking as I have a bead on another 3870 (this one a Diamond Viper)and was curious if it was really worth the money.

I was even considering selling the two 3870's I have for a 4870 if the performance is noticeably better. The two 3870's are overclocked via ATI overdrive and was able to achieve a decent overclock due to good cooling. (from 775 stock to ~836Mhz+)

I pretty much only play COD4 and the latest unreal Tournament. ( of course the new COD when it's released lol )

I also recently posted to the hardware troubleshooting due to issues with running x-fire in the two primary slots on the board. Come to find out its a defective asus interconnect cable. That being the only 'longer' interconnect cable I have, I am running 1 card x16 and the other in a x8 slot. sucky.

if your board supports pcie- 2.0 then you are getting full 16x bandwidth from the 8x slot. even if it isn't the 3870's likely aren't even close to maximizing the 8x bandwidth.

Well when I run any type of test for example cpu-z , it shows one card as 16x and another card running 8x. The slot in the bios is an 8x slot.

The two 'blue' primary slots are 16x - which wont work as my Asus interconnect is fubar'd

pci 2.0 doubles the lanes of the original spec upto 32 lanes so
pcie 1.xx
8x has 8 lanes
16x has 16 lanes

pcie 2.0
8x has 16 lanes
16x has 32 lanes


so you see if your board supports pcie 2.0 then you are getting the full 16 lanes from 8x slot.
but again you will se no performance difference between 8,16,32 lanes with a 3870 gpu, its simply not fast enough to use the bandwidth provided.
the worst was the 965's 16x/4x config...

Excellent. The board has PCI-E 2.0

I guess I am rather finicky. I like to run things in the proper slot - it would also clear a pci slot for a sound card as well as I am not overly impressed with the onboard audio, even when running it thru optical.

I can put my audio card in, but it leaves very little room for the 3870 to deep breathe lol