Can two 7850s be CrossFired with a Trinity processor?
A Bad Day
As the title asked, I was wondering if it was possible to CrossFire them. I know that CC 10.3 allowed CF between different architectures (6000s paired with 7000s for example).
A Bad Day said:As the title asked, I was wondering if it was possible to CrossFire them. I know that CC 10.3 allowed CF between different architectures (6000s paired with 7000s for example).
a link to that plz. i think it meant the rebagded 7k series gpus (e.g. 7670) can cfx with 6000 series gpus (e.g. 6670), not the gcn ones. iirc one can cfx 5770 with a 6770. i could be wrong though. here's a compatibility list:
i don't see any 6000 series + 7000 series being compatible for crossfire.
from toms' preview, the top desktop igpu looks like a bit below a radeon hd 6670 in terms of gpu performance. meanwhile, a single 7850 is much more powerful than a 6670. it doesn't make sense to use a 7850 with a much weaker igpu. however, it seems that trinity, with an appropriate chipset can divide it's 16 pcie 2.1 lanes into 8 lanes each and run two discreet cards in x8 modes if the motherboards allow it. 'triple-firing' 6670 may be impossible (apu+ 2x 6670) but running 2x 7850 in cfx might be possible. in that situation, trinity's cpu part will have to be powerful enough to run the two 7850s without bottlenecking them.
A Bad Day said:Why is triple-firing 6670s with APU is impossible? I thought the only restriction was the number of available CF bridge ports. I know that triple-firing 6870s (6870 2x with 6870) is possible.
okay, i just read that someone has managed to (in their own words) 'crossfire' two 6570 with a llano apu. the screenshot showed that 3 gpus were available and crossfire was enabled, no mention of which gpus were in crossfire or if the igpu was in cfx. there is no test data or benchmarks available at this moment.
6870s are discreet cards' gpus. besides, triplefiring cards add cost and not enough performance in most cases. you'd also need application profiles for triplefire configuration. the cpus will have to be powerful to run 3 gpus in combo. i doubt apus' cpu will be that powerful. i could be wrong though. i hope someone tests that.triny said:7750 and 7770 is my expert opinion
7670 is OEM only
your 'expert opinion' is just an opinion until you provide proof.A Bad Day said:So if I was to get the A-10 5800K, which GPU (7750/7770) would have the closest performance to the APU's GPU? I plan on getting two passive cooled 77xxs and taping fans to them.
5800k's igpu seems slower than discreet 6670 but faster than 6550. 7750 is faster than 6670 while 7770 is close to 6850 (much faster than 6670).
you can use the gaming gfx hierarchy chart (compare llano's igpu 6550d, 6670, 7750 and 7770's standings)
imo you should wait till desktop trinities launch in retail and gets benchmarked in more detail. toms' article was a preview of what to expect. by the time trinity comes out, amd might have more mature drivers, better and finished motherboards will be out. with those available you would be able to make a better and more informed decision.