I must not have been clear..... historically, the SC series has utilized a stock PCB and added a very nice
GPU cooler. Note the bolded text emphasis. They do do an excellent in cooling the GPU.... less so for the memory and VRMs. They also normally use the reference VRM whereas competitors use custom PCB and bigger VRM with more phases.
Let's look at the waterblock round up for the 780 / 780Ti / Titan
As you can see here, the EVGA Hydrocopper comes in 2nd place on GPU temps ...about 2 C lower than industry leader EK...GPU temps under water typically run 39 to 45 ish so 1) EVGA did excellent in coming in 2nd, but 2) last place is only 2 C behind
Now lets look at VRAM temps .... EK goes to 1st place, but EVGA is in last, but this time the spread is 10C
Now finally, lets look at VRMs ....EK's in first again with a 33C...but EVGA is in last place again with a 30C increase..... so while the SCs do generally cool the GPU very well, they are not so good at cooling VRAM and especially VRMs.
Now I'm going to make it even more confusing
At stock, the EVGA VRAM and VRM temps are generally cooler than competitors, that is because the EVGA fan is spinning quite a bit faster. Now overclock both the cards and the EVGA has less rpm headroom so it can only increase its cooling potential so far.... the other cards, were running slower to begin with so they have more untapped cooling capacity.
Here's a good teardown article on the 970s .... note the differences in VRMs and memory componentry and cooling
http://www.bit-tech.net/hardware/graphics/2014/09/19/nvidia-geforce-gtx-970-review/3
Examining the PCB reveals a 4+2 phase power design – four phases near the rear I/O for the GPU, and two in the bottom right corner for the memory. This is a slight upgrade from the 4+1 stock specification but unlike MSI and ASUS, EVGA does not use any specially crafted components.
The GPU MOSFETs are directly cooled by the main heatsink, which has a thermal strip on to draw heat up into the fin stack. On the other side of the GPU is a metal contact plate that partirally cools two of the four memory chips on this side, leaving the other two exposed. It also cools the MOSFETs of the power phases serving the memory, but no thermal pads are used, so heat transfer is likely to be limited.
The power delivery is the best of any here; it's a 6+2 design. Further, MSI uses its own improved components for both the GPU and the memory power phases. The components are referred to as Military Class 4 since they meet MIL-STD-810G regulations. Specifically, we find Hi-c CAP and Solid CAP type capacitors and Super Ferrite Chokes, which are designed to provide higher stability, lifespan and efficiency.
A miniature heatsink takes care of cooling the main GPU MOSFETs near the rear I/O, while a metal contact plate equipped with thermal pads is used to cool three of the four front PCB memory chips as well as the remaining power circuitry including the memory MOSFETs and the VR controllers.
So appreciating your responsible attention to GPU temps, just wanted to note that your concern should not lie solely with the GPU, think about VRAM and VRM temps too.