LOL both of those systems are so sick... that's a bit like asking if your "700HP ferrari doesn't murder your 500HP lambo?"
"I mean yeah... but... that one is yellow"
Well, it depends on how you compare it. Maybe both have the same amount of power, but one is better at some tasks for the other. For example, I was driving my mother's BMW since my car needed work and it's quick and peppy and all, but it's a small 6 (2.5L) with only about 200HP and All wheel drive. I get my Saab 9-5 Aero (2.3L 4 with high output turbo,) back and it's not as peppy, but on the highway you give it some gas, that Turbo throws you back into the seat. So I think it's more like the difference between having a lot of torque and a lot of HP.
My 3820 loves multithreaded tasks, but give it a single-threaded task and a 2600k (overclocked to same clocks,) very well could do better. Not that the results very too much, but there are benefits and drawbacks to having quad-channel memory and more cache, which is usually a latency issue, but that quad-channel memory shines as soon as you hit memory hard with one, thread, two, three, and four. Any more than 2 memory heavy threads on a 2600k and it will start to slow down the other cores. (SB and IVB have better per-thread memory speeds, but SB-E has a lot of raw throughput for multithreaded tasks.)
Just my take.