Will a non-Ghz 7970 Crossfire with a r9 280x?

[withered3eye]

See ^Title^ Please.

 

[nikoli707]

yes... as long as both gpus are the same core chip(tahiti in this case) and have the same core/stream processors(2048 in this case), you can crossfire them.

 

[withered3eye]

Awesome, those both match, only differences is the core clock is 50 mhz higher on the 280x. Would you recommend downclocking the 280x to equal 1000 mhz or do you think it will downclock itself better?

 

[nikoli707]

Awesome, those both match, only differences is the core clock is 50 mhz higher on the 280x. Would you recommend downclocking the 280x to equal 1000 mhz or do you think it will downclock itself better?

i believe they will downclock each other to whatever the lower clocked card is. if your going to overclock though, you can just dial in both cards to the fan settings you feel comfortable with and find the sweet spot and force them to be the same clocks. either way they will work fine together.

whats the rest of the parts in your rig?

 

[withered3eye]

i5 3570k @ 4.2 ghz
Hyper 212 EVO in Push/Pull
Asrock Extreme 4 z77
16 gb Corsair Vengeance 1600hz (dual Channel)
Currently a 620w Seasonic m12 PSU
Gigabyte 7970
120 gb SSD
1 Tb HDD
Adding a 1000w Antec HCP Platinum
Adding a Sapphire r9 280x

 

[nikoli707]

that antec platinum 1000w is way overkill. do you need platinum certification for something?

PCPartPicker part list / Price breakdown by merchant

Power Supply: XFX ProSeries 850W 80+ Gold Certified Fully-Modular ATX Power Supply ($134.99 @ NCIX US)
Total: $134.99
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2014-08-16 13:42 EDT-0400

plenty of wattage and a great power supply with gold certification if your trying to be green.

other wise your good to go.

 

[withered3eye]

I got it on sale, it's used, I was going to buy an EVGA 850w Gold but dude backed out on me, and i got the Antec for near same price. I figured a bit of future-proofing, I plan on doing a new pc in the future so it'll be nice to have the 620 for a single card setup, and the 1000w for dual setups with more power needs in the future. Or at least I'm thinking. Thanks for the replys man, very helpful.

 

[withered3eye]

Would you recommend putting the 280x in the first slot or the 7970? Only thing that is still bothering me.

 

[Jay Lavistria]

Depends. What coolers are both cards running?

 

[withered3eye]

Well the Gigabyte is a non Ghz 7970. They use Windforce, which is a 3 fan set up. I have a Sapphire r9 280x being shipped to me, and it will be a dual fan set up. I didn't think the stock cooling systems would be the deciding factor.

 

[Jay Lavistria]

Well some coolers enjoy having more open air, and some enjoy being behind another card.
From the looks of things, if I just slapped them on without thought, I'd put the Windforce on top and the sapphire on bottom.
If you really wanna know, test each card one by one and see which one is cooler.
The coolest one should be on top and warmest on bottom.

 

[withered3eye]

"The coolest one should be on top and warmest on bottom."

Sounds like a plan.

 

[nikoli707]

yes... test each card out and find a good modest overclock with the same voltage and the same core clock, same with memory too, and run something like unigine valley in a loop for 20 minutes(test for stability too) and let msi afterburners hardware monitor log the temps and other crap.

then put the cooler card on top, warmer on bottom... like said before... and retest with valley in a loop and keep an eye on temps. dont let the cards get above 80c. you probably want to get lower temps anyways but whatever temp and fan profiles you pick is up to you. 80c is more than fine for core temps but without knowing what the vrm/mosfet temps are its better to be on the safe side and have a max of like 72-75c in valley. your should be slightly lower in games.