A Close Race Today, But Tomorrow Shows More Promise For AMD
We're already intimately familiar with the Bulldozer and Ivy Bridge architectures, so nothing that we saw today is particularly surprising. Single-threaded applications are going to hum on Intel's chip, while applications able to tax the FX's four integer clusters are going to treat two Bulldozer modules more like a quad-core processor (not quite, though, as the Core i5's stellar performance demonstrates).
The real questions, then, are: what does a dramatically higher clock rate do for AMD's offering, specifically, what does that bump up to a 125 W TDP do for power consumption, and how does Intel compare, given its dual-core implementation?
Despite proof that some of the games we tested do take advantage of quad-core CPUs, the dual-core Core i3-3220 takes a lead in this discipline, mostly a result of Skyrim. The FX-4170, on the other hand, serves up better application performance, and by a larger margin. When you consider the way people use their PCs, we're inclined to put more value on the larger productivity win favoring AMD, particularly since the apps where an FX excels are threaded. Those are the workloads that require more processing power.
If we were to make our judgement on performance alone, AMD's FX-4170 would have the edge.
But there's another side to this story. It starts with power consumption, and ends with efficiency.
At idle, the FX-4170-based machine uses almost 20 W more than the Core i3-3220-based box. Under load, that gap grows to a staggering 103 W. The dual-module FX almost doubles the consumption of a quad-core Core i5, in fact.
Yes, the load comes from a largely-synthetic Prime95 run, and yes, it's unlikely you'll ever see such nasty power numbers on a day to day basis. Nevertheless, two times the power consumption really puts AMD's small performance advantage into context. Efficient, this CPU is not. Whether or not that matters to you is a personal decision.
What we're really looking forward to, though, is Vishera. Intel put its cards on the table earlier this year with its Ivy Bridge architecture, and Haswell-based chips won't show up until the second quarter of next year. More immediately, we're expecting FX CPUs based on AMD's Piledriver architecture this month. We've seen evidence that Piledriver may add up to 15% more performance in the same thermal envelope as Bulldozer. If that holds true, then a processor with two Piledriver modules in the same $125 range should help the company claw back some of the performance/watt deficit it currently suffers.
You can bet we'll revisit this topic when those chips start showing up.