"CrossFiring" on the Bad Axe 2 (I975x) Mobo

[P220ST]

I'm getting a new system set up and was doing some research on CrossFire technology as I went with Intel's I975X Bad Axe 2 (over Asus/nForce). Bad Axe 2: gotta love that moniker! Anyway, I was doing fine until I came across this:

and immediately had acid flashbacks to the days of Canopus Pure3D 3Dfx Voodoo2 X2s DVI'd with the same thing behind my chassis. I think.

And I have to come clean. I'm the one who bought the Quantum3D Obsidian2 X-24.

Anyway, now that confessional is over, back to CrossFire technology. I'm misunderstanding something. Am I restricted to a certain group of video-cards that embrace the technology? That is, does ATI inhabit the CrossFire market alone, or would anything, even a pair of SLIable NVIDIAs work? And all other things being equal, would my graphics performance benefit more from a pair of "CrossFired" mid-level ATI cards than an equivalent pair of mid-level NVIDIAs?

Finally, is the performance kick from CrossFiring any better or worse than SLI? I know that I could post this to a gamers forum but I prefer the knowledge base over here. I'm Googling the topic, but if you've happened across a good educational site on it, please let me know!

Thanks for Reading,
-P220ST

 

[Nelviticus]

Crossfire is ATI's name for its two-card set-up. nVidia's version is called Scalable Link Interface, or SLI. The two are not compatible.

If you want to run either, you'll need a motherboard and a pair of graphics cards that all support the same flavour, so a pair of nVidia cards wouldn't work on a Crossfire motherboard.

"Would my graphics performance benefit more from a pair of 'CrossFired' mid-level ATI cards than an equivalent pair of mid-level NVIDIAs" - I suggest you have a look at the dual-card VGA Charts on Tom's Hardware. You can compare the performance of various set-ups in various benchmarks, it's really very handy.

Regards

Nelviticus

 

[P220ST]

Nelviticus,

Thanks for your reply. My Mobo is definitely CrossFire and CrossFire only. My mainmisunderstanding is what video cards can be used in a crossfire board. All? A subset that are "CrossFire compatable"?

That's my primary confusion.

Thank you for the link. It's open on another widow and quite helpful. I appreciate your time.

Take Care,
-P220ST

 

[Nelviticus]

It depends on the card - quoting from the Wiki page:

Radeon x800s, x850s, x1800s and x1900s come in a 'CrossFire Edition' that has 'master' capability built into the hardware. One must buy a Master card, and pair it with a normal card from the same series. Radeon x1300s and x1600s have no 'CrossFire Edition' but are enabled via software.

So depending on the card you go for you'll either need a special 'master' CrossFire one and a normal one (x800, x850, x1800 and x1900) or just two normal ones (x1300, x1600).

Regards

Nelviticus

 

[P220ST]

That makes more sense. Thanks. In addition to the ones that are cabled together (DVI - see my original post), the are also dual sets where ATI decided to use the PCI Express bus. As the cards will not likely saturate the PCI Express bus, even with two of them, this seems reasonable. To operate X1600 in Crossfire mode, simply install the two cards, install the drivers and enable Crossfire. Voila!

My question: what if you need the absolute amount of deliverable power and bandwith for you primary function (I make music on my computer)? Wouldn't I be shooting myself in the foot. Just a little bit - with this versus the traditional two CrossFire cards, DVI cabled in back?

I have a mutually exclusive problem in that I'm trying to do some small time video editing with the music (MTV style, well - old MTV style).

Take care and again, thanks,
-P220ST

 

[P220ST]

Follow Up Questions:

Re video playback - have any vid cards shown themself to be a best bet?
Again w/ the CrossFire platform thing: does it matter at all?

 

[Nelviticus]

If you're playing a game and you're loading a lot of textures then a lot of data is going to be passing over the bus but in normal use this won't happen. I guess if you were playing highly graphical games and doing something else enormously demanding such as transferring lots of data over a gigabit network and sampling audio at extremely high quality - all using PCIe cards - you could, in theory, saturate the PCIe bus. I don't know how much it would take though - PCIe can handle 250MB/s and you're very unlikely to be doing all of those things at once.

If you're just sitting there doing music-y stuff the fact that you happen to have a pair of Crossfire cards installed won't affect your performance. It just means that you have the graphical power on tap when you need it.

Regarding video playback, it depends what you're after. For normal, non-high def video any card will be fine. For high def video which is encrypted you'll need a graphics card and a monitor which both support HDCP. As for quality, a recent article on Tom's Hardware discussed this very thing.

Regards

Nelviticus

 

[paparazi]

I've own several crossfire and SLI motherboards and to be honest I just cannot see the point in installing two midrange cards which together cost the same as one higher end card and often are beaton by that single card.
For example:
In the overal All Games fps test
An X1650Pro gets 667.8
and a X1900XT gets 1426.9

now I think we are talking similay money for two X1650Pros but obviously that figure of 667.9 certainly doesn't double when installed in crossfire mode.

So you'll need to be a little careful when sellecting those cards, to make sure the combined price isn't capable of purchasing a single card that will out perform the two.
Martin

We like members to GIVE and not just TAKE.
Participate and help others.

 

[P220ST]

You guys have been immensely helpful. Unfortunately youve driven me to a decision point and another question, posted above.

Thank you for you help.

-P220ST