Hybrid CrossFire and multiple monitors

I read the [H] & Anandtech's previews of hybrid CrossFire from last December, but neither really touched on the multiple monitor aspect. Is there anyone out there using a multiple monitor setup with hybrid CrossFire? What's the scenario? Is it DVI & DSub only? are the outputs run only from the mobo?

If I read correctly, running say a 4850 with a 790GX IGP really won't bring any performance increases with hybrid CrossFire, but having the system setup to only use the discrete card when necessary would definitely save on the power consumption. The only issue is that I (along with many ppl these days) use more than one monitor.

Brent? Kyle? Bueller?

From the PCPerspective article, here:

AMD also talked about the future ability to feed the power of a discrete GPU directly to an IGP and pass it through to a monitor. What’s the benefit of this? Say you have a high end HD 3870 graphics card installed in your RS780 motherboard. Now these two GPUs can’t really work together in hybrid CrossFire mode because the HD 3870 is so much faster than the RV620-based GPU in the IGP. However, if you have your monitor plugged into the DVI output on the motherboard rather than the HD 3870, the HD 3870 could render your games and feed that through the PCI Express bus, to the north bridge and out to the monitor through the IGP output. The benefit that gives you is that the HD 3870 can then be completely powered down to its lower power consuming state when you are not gaming. This would give the user a more power efficient system without sacrificing GPU performance.

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Now, to me, this says that the Hybrid setup is all done via the outputs on the motherboard, but that your discrete card will render the game & send the data up the PCIe bus when necessary. Does anyone out there have experience with this type of setup?

Also, from the same article:

First, as we first talked about during the HD 3850 and 3870 review, AMD is going to be tweaking the CrossFire driver to allow you to run in CrossFire mode while using more than one monitor.

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So does this mean that you could potentially use both outputs on the motherboard (one of them, unfortunately VGA), run both outputs to separate monitors, & have the discrete card power itself on when needed to run your games? Anyone out there doing this now?

I'm really interested in the power/heat savings this kind of setup would generate, & if it works as described above, it'd definitely be the decision-maker for me going with a GX board instead of one of the new, re-vamped FX boards. Only problem is that I can't find info anywhere on anyone actually running this kind of setup...

I haven't used Hybrid Crossfire myself, but I also have a fair few questions. For me, namely I'm concerned with the performance of Hybrid Crossfire versus simply dropping an HD 3600 in.

I've been considering building a high-performance gaming rig once the SB750 South Bridges start hitting the market paired with a 790FX, but having also considered multiple-monitors as an option, it seems like a good idea to grab a GX. The only thing holding me back is the x8 + x8 electrical PCIe; granted it's 2.0, so basically PCIe 1.1 x16... but the 790FX is much more future-proof with PCIe 2.0 x16s (x4!)

Seems like someone with a 780G should be able to pipe up about your question though T, as I don't think the 790GX brings anything new to the plate other than a pumped-up IGP. I got the distinct impression that with Hybrid CrossfireX, you should be able to run multiple monitors as well. At the very least, shouldn't you be able to run another monitor using Triple Hybrid CrossfireX? Or maybe even Dual Hybrid CrossfireX for your primary monitor and a second discrete card handling your extended desktop?

Hmm... hopefully the folks over at OCWorkbench will expand upon their 790GX Gigabyte review and answer a few of the questions regarding the 790GX, and Hybrid CrossfireX + multi monitor support. Otherwise, perhaps someone with a 780G can chime in here.

Right, I thought for sure that some 780G people would be able to add something to this thread... I can hear the crickets in here. Heh.

Yeah, the x8 + x8 won't really affect me b/c I don't really see myself ever running 2 discrete cards. Having the discrete card dynamically powered on/off, though, really piques my interest. I'd suffer through the motherboard VGA out to get that functionality on my 2 monitors....

Hybrid crossfire is only supported by 34xx cards i believe i am not sure if they have updated the new chip for higher models.

Well, the PCPerspective article I quote above clearly references 38xx cards, & they were basing that article on the (then not yet released) 780G chipset, so they've either got it wrong, or wherever you heard it from does. Do you have a link?

http://www.hardwarezone.com/ourvoic...Preview-ECS-A780GM-A-Mixes-Up-Geek-And-Thrift

I own 3850 and 3870
and a 780G Hybrid board.
None work. I contacted admins on the amd forum they also state only 2xxx and 34xx models are supported atm.
There might be newer boards that will support it in the future.

Let me dig up 3 other sites that tried the 38xx on them.

http://www.anandtech.com/video/showdoc.aspx?i=3178
Also states its designed for 2xxx and 34xx series.
38xx wont benifit.

http://www.pcper.com/article.php?aid=498
States also its for lower cards only atm. there are plans to make hybrid crossfire for higher end cards. but the current mobo cant do it.

I am hoping they coming out with a board that will support 38xx series.

Yeah, I tried to edit my post last night, but the forums went to shit on me. Tom's article on the 780G here, states this:

We conducted the Hybrid CrossFire tests using a Radeon HD3450, and out of interest, also installed a Radeon HD3850. However, the on-board GPU automatically deactivated itself, so it was no longer available to create a CrossFire combination.

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Then, this ExtremeTech article on the 780G says this:

We'd like to see the ability for users to plug in a high-end graphics card, using it alone when playing a 3D game and using the integrated graphics when running basic desktop applications, just to save power. That's a feature Nvidia is working on, but ATI has no immediate plans for it.

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So... I guess we can only hope that ATi did right by the GX, & implemented these features/functions. I guess we'll see soon enough; looks like many of the boards are selling already.

Edit: in addition to 4 boards listed at Newegg, AMD's press release is now up. I'm thinking the official launch is upon us. The press release doesn't, however, go into any detail about which cards will do the Hybrid CrossFire

The hybrid crossfire and the "power down your high end card when not playing games" technology are two different terms as far as I knew/thought. I also thought that it was enabled only in vista. If someone wants to give me a copy of Vista x64 I will test the power down scenario But yea Hybrid crossfire, where you combine a discrete card and integrated card to get more performance, only works on the load end cards (2400, 3400, etc.)

Yo Myrandex. Yeah. We discussed that matter further in this thread.