Conclusion
First of all,
let us talk about prices. For the sake of argument, let us consider that
the two Radeon R9 270 graphics cards cost 272 Euro and compare that to the
331 Euro you would have to pay for the cheapest reference Radeon R9 290 we can
find. Therefore, this one high-end card is is going to be 22 percent more
expensive than the
two mid-range cards.
To dive a bit deeper into the results, we start with performance differences in
3DMark graphics score where we see that the CrossFire of the two R9 270 is
about a percent faster
than the Radeon R9 290 in case of the graphics score. In the next theoretical test we ran, Unigine Heaven, we
see that the two R9 270 graphics cards are, on average, 24 percent slower than the
R9
290. In case of games it turns out that, for example in Skyrim,
a
single Radeon R9 290 card is about 36 percent faster than the two R9 270
graphics cards in CrossFire. A
closer look at the Call of Duty: Black Ops 2 shows the other end of the scale, where
the two R9 270 score 21 percent better than the single Radeon R9 290.
Overall the two R9 270 graphics cards are performing really well on average,
while in the end, the R9 290
is still 3.1 percent faster than two R9 270 in CrossFire. The bigger problem is that the average value is not telling half the story. It turns out that in one of the games
we tested, the single card was faster, but then, there are games where the difference is small and, last but not least, there are some titles where the two
R9 270 cards are a lot faster. This in the end makes the performance rather unpredictable.
Maybe a look at power
consumption is going to make things more interesting. In idle, the power consumption of our test system is
26 percent higher with two R9
270 compared to one R9 290 and under load conditions the story changes, as the
single Radeon R9 290 graphics card burns 30 percent more power than two
Radeon R9 270 graphics cards. So basically the CrossFire setup under load
burns about 30 percent less power but is just about 3 percent slower. This is
certainly an interesting bottom line in if you should already own a Radeon R9
270 card, adding another one to your system will make it quite quick for gaming.
If you're considering to buy something completely new, then we would always opt
for the single high-end card, since you get consitent performance and
substantially higher energy efficiency in idle.