All of the 'real world' i.e. rendering the 6-core is going to stomp the SB. Further, no one buying (few maybe) are going to run the i7-980X @ 3.3GHz. Mine (my daughter's) has been running between 4.4GHz and 4.6GHz since the day I bought it.
The problem is those this vs that are very misleading because so many operations (benches) are based upon Default clocks and not remotely what the CPU is capable of doing.
Tossing out a $1000 i7-980X over a MOBO IMO is nuts. I'm not suggesting that anyone today should go out and buy an LGA 1366 CPU.
In my daughter's rig the GPU's are being replaced by 3-WAY GTX 680 4GB, everything is blocked. So I'd have a tough time justifying - NEW ($2000+): CPU, MOBO, RAM, MOBO block not to mention several hours for a couple FPS. Instead once stuff dies then 9/10 an IB-E or whatever is available at that time.
Here's a OC comparison, but keep in mind I have a 5GHz profile for my i7-980X - http://www.bit-tech.net/hardware/cpus/2011/01/03/intel-sandy-bridge-review/7
/Edit = don't forget I have an i7-3930K @ 4.8GHz - http://valid.canardpc.com/show_oc.php?id=2261309
So I if anyone knows!
CPU Hierarchy - http://www.cpubenchmark.net/high_end_cpus.html