Tripple channel i7 960 vs dual channel 2600k‏

[Ilya]

Question for all,
I've been researching on the subject of benefits of an extra channel of memory. Now, research shows that for gaming, an extra channel doesn't add a whole lot of performance advantage, that, however, could be because games usually do not require moving large amounts of data. BUT, if you're doing 3D rendering, encoding or things that require a lot of ram and video memory would a dual-channel start to slack behind tripple channel because of bandwidth shortage? Answer is obvious, of course it will. But by how much?

Now the kicker, would the architecture/frequency benefits of sandybridge 2600k compensate for the lack of an extra channel in real life situations for media/3d workstation?

The benchmarks show that yes, 2600k outperforms i7 950(which is only a bit slower than 960) by a good margin especially in rendering/encoding times. However, all of the benchmarks are testing quite small files (500mb). Does this test show reality of RL? Or in real life with huge files the dual-channel will start to bottle neck lightning fast 2600k?

For the sake of an argument let's add a non-existent but soon-to-come mobo Z68 which will add a feature where you will be able to use Sandybridge's utility "Quick sync" AND graphics card at the same time(at this time this is unavailable).

So, bottom line question. For a media/3D workstation, with all pros and cons considered, would you rather go with triple channel 1600mhz i7 960 or dual channel 1600mhz 2600k?