Will a 7970 non-ghz edition crossfire with a 280x? Please read description!

TechiGamer · Jun 27, 2014

Hi !

I was taking a look on ebay and found a really good deal on a 280x. However, to my disappointment, my local retailer as well as MSI said that a r9 280x and 7970 OC edition will NOT crossfire successfully. Seems quite controversial since nearly every forum said you can ,yet these professional companies say I can't. I'm really confused at the moment. Can anyone please explain if it can or cannot?
What MSI said was that it has to be the same card. But I though that a 7970 and r9 280x are literally the same thing except for different clock frequencies.

So if such a small difference makes it unable to crossfire than how can a 7950 and 7970 crossfire? This is not making sense.

* Edit * I am trying to crossifre an r9 280x MSI and a gigabyte 7970 OC edition ( not ghz edition )

* Edit * I just phoned up NCIX techsupport and they said that it will crossfire, but the different bios will affect performance. How much loss in performance would I see in comparison to 2 7970's crossfired?

Tcinator · Jun 27, 2014

the chip has a different name embedded in the controller, and that's what it bases compatibility for crossfire off of. that's why different brands and speeds still will work together. If you get it working, that would be pretty awesome. I haven't done any specific research but im pretty sure that's a no-go. And if you can, it would be through a warranty voiding hack.

dudewitbow · Jun 27, 2014

I wouldn't see why not. They both use the same core in essence, the only real difference is clocks and name on the gpu's bios. Even so, I would think it would be possible to flash one bios to the other, making it 100% sure that its possible

C12Friedman · Jun 28, 2014

Here are two articles and a video that "cover" that, they are a few months old now but, if accurate may be of help
http://www.tomshardware.com/news/radeon-r9-280x-radeon-hd-7970-crossfire-compatible,24619.html
http://www.thinkcomputers.org/amd-radeon-r9-280x-compatible-with-hd-7970-in-crossfire-mode/
https://teksyndicate.com/videos/we-crossfire-msi-r9-280x-7970-frametimes-benchmarks-discussion
I didn't come across many threads of issues when I searched so...

TechiGamer · Jun 28, 2014

C12Friedman :

Thats great info. But my main main concern is that all of these forums and articles talk about using a 7970 GHZ edition with the 280x. So will a regular OC 7970 work?

TechiGamer · Jun 28, 2014

C12Friedman :

Actually it does work like I believed all this time!!!! I'm shocked though that Memory Express AND MSI both told me that it would not! wow.

Anyways, do I need to plug in both crossfire bridges or do I only need to use 1 bridge?
Is there any special software required?

dudewitbow · Jun 28, 2014

TechiGamer :

C12Friedman :

Actually it does work like I believed all this time!!!! I'm shocked though that Memory Express AND MSI both told me that it would not! wow.

Anyways, do I need to plug in both crossfire bridges or do I only need to use 1 bridge?
Is there any special software required?

you only need one. Multiple crossfire bridges are for setups past 2 cards

TechiGamer · Jun 28, 2014

dudewitbow :

TechiGamer :

you only need one. Multiple crossfire bridges are for setups past 2 cards

Is there any special software required?

C12Friedman · Jun 28, 2014

TechiGamer :

The latest drivers from AMD should give the best performance, other than that, no. The Crossfire-X selection will be in the Catalyst Control Center

TechiGamer · Jul 2, 2014

C12Friedman :

Do you know if it matters where you place the cards? So, would it matter if I had the 280x in the first slot and the 7970 in the second or vice versa? Would it matter at all?

C12Friedman · Jul 2, 2014

I would want to put the R9-280X in the first slot as master - I don't know if that is what is suggested, just what I would want to do.

Tcinator · Jul 2, 2014

No, the only limitation would be if the second slots was a x8 PCI-e which would cause the crossfire to run at 2 x8 rather than 2 x16. The only concern would be cabling and airflow. x8 performance isn't too far off in benchmarks and most boards now are x16 so literally there is nothing to stop you from putting either in first. both cards sync up to the lowest clock speed of the 2 so as Friedman said, its all preference.

TechiGamer · Jul 2, 2014

Tcinator :

hmm. Well believe it or not but my z87-d3hp motherboard is x16 and x4. All this time I was positive it was x8. Will a I see a Huge crash in performance with a x4?
I think I might just sell this motherboard with all of the regrets I have been having...

Tcinator · Jul 2, 2014

TechiGamer :

... Yeah you are better off running a single card. at x16.

TechiGamer · Jul 2, 2014

Tcinator :

You really think so? I was just scrolling through a few forums and it seems like there is not a HUGE decrease in performance...

Tcinator · Jul 2, 2014

TechiGamer :

Your right. there isn't MUCH of one. I revise my statement you have the right info. Go for it. It will still out perform a single 280x or 7970 oc.

That also does depend on what revision of pci-e you have on your board as well

TechiGamer · Jul 2, 2014

Tcinator :

Will there be a fairly large decrease when compared to x16 x8 configuration ?

Tcinator · Jul 2, 2014

TechiGamer :

Maybe 5-10 frames difference. but that's talking about a x16 x8 crossfire. not a single card. There will still be a benefit to the crossfire. I cant find exact #'s but I would guess another 15-30 frame boost on most games.

TechiGamer · Jul 2, 2014

Tcinator :

TechiGamer :

Maybe 5-10 frames difference. but that's talking about a x16 x8 crossfire. not a single card. There will still be a benefit to the crossfire. I cant find exact #'s but I would guess another 15-30 frame boost on most games.

I see. Micro stuttering has been fixed, right?

Tcinator · Jul 2, 2014

TechiGamer :

you know, im not sure if they resolved it all the way.. I haven't followed up on that for a while. you could head over to pcper.com. theyre the guys who invented the framerating benchmarking to analyze that issue in detail.

TechiGamer · Jul 2, 2014

Tcinator :

Thanks

I'll check it out. By the way, what is a good software to measure frame rates with Mantle?

Tcinator · Jul 2, 2014

most games have integrated fps solutions. if its battlefield its something like opening the console and typing render.draw fps 1 or something.

TechiGamer · Jul 3, 2014

Tcinator :

I have been looking for a new motherboard and so I was wondering if it is possible to have a x16 x16 configuration with crossfire? Because so far, all of the motherboards I have looked at, the maximum bandwidth is x8 x8 for crossfire. Any recommendations?

Tcinator · Jul 3, 2014

TechiGamer :

there are many boards that have multiple x16 slots. but starting price is usually in the mid 100's and up depending on pci-e version they can be cheaper. what cpu did you say you had?

TechiGamer · Jul 3, 2014

Tcinator :

I have an 1150 ( i5 4670k ). I have heard that quite a few have x16 x16 but they actually only work in x8 x8 !?!?! I only heard that so I'm not sure if that is actually true. That statement was made by a sales person at Memory Express. Is that really true?

Will a 7970 non-ghz edition crossfire with a 280x? Please read description!

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