I bought the EK waterblock itself, without the backplate. I'd read that the EVGA couldn't be used because of a screw mismatch or something like that. That was hogwash. Aside from the four screws surrounding the gpu mount, there were two or three other screws that had to be screwed in first before the backplate was put on. I made sure there would be enough clearance, but since those screws had been under the backplate holding the ACX 3.0 cooler before, there was obviously no problem. Exactly two screw holes exist on the EVGA backplate that aren't used with the EK waterblock, because the waterblock has no corresponding threaded hole where those backplate holes are. It was absolutely trivial.
 
So, someone tell me again why people saying the EVGA backplate can't be used with the EK waterblock, and you have to buy the backplate from EK.
 
The two screw holes in the EVGA backplate that weren't used are the two north/south oriented holes in the middle of the gpu mount area.
 
Pics or it didn't happen:

The nice thing is I only paid $129 for the waterblock only (acrylic/nickel) instead of $160 with the backplate. If I'd really wanted to cheap out I could have paid only $113 for the non-nickeled copper block.

Anyhow, all the pieces in my monster build are coming together. My i7 6900 will be here next week, then it's on like donkey kong.

A 240 that is cooling your GPU+CPU will give you high 40s in TimeSpy? What is the speed of the fans at this time? Above 1200rpm?

Dschijn
A 240 that is cooling your GPU+CPU will give you high 40s in TimeSpy? What is the speed of the fans at this time? Above 1200rpm?

I just finished up a series of Time Spy, Fire Strike Ultra, and Fire Strike. The temperature was at 49 most of the time while running these. I think the time in between runs let the heat load in the water get lowered by the radiator. Then I ran Valley for 20 minutes, and around halfway through that time it climbed to 51 C and stayed there for the rest of the 20 minutes. Tomorrow I may well let it run for an hour or so to find out if that's really the final answer.
 
At +170/+450 I was able to successfully run Fire Strike Ultra and Time Spy, and set new personal records in both of those. Trying to run Fire Strike at those speeds, however, the machine crashed. While running Valley at +160/+450 I saw the occasional artifact. I think I'll just set the OC to +150/+450 and leave it, though I may experiment with the memory clock a little.
 
This is way higher of an OC than I was able to get on air with this 1080 SC. I'm definitely impressed with the EK block. I'm also very impressed with the Swiftech H220-X system.

Btw, this morning I ran Valley at 3840x2160 at Ultra settings include 8x AA for an hour, and the gpu temperature was between 49-50 C after the first few minutes, and stayed that way for the rest of the hour. If the Swiftech 2x120 rad can do that shared with my overclocked cpu, I can hardly wait to see what temps I get with my monster case once the two 2x180 radiators are added to the loop.
 
Was the EK worth it? Who knows. I'm certainly getting significantly better overclocks with it than I got on air. I know my game performance won't drop due to boost 3.0 reaching temperature limits. Whether that's worth $129 or not is impossible to answer, since it's just a value judgment. I'm happy as a clam with it though. I'm also very happy I was able to reuse the EVGA backplate with it.

Cool GTX
However My 5960X OC at 4.0 and a full load (folding) pushes the cooler to 70 C in a 28 C room

Yeah, this load I'm testing is a gpu stress load, not a "generate as much heat as physically possible" load. Without the gpu, my cpu would hit something like high 50s or low 60s if I ran Prime95 on it for quite a while, or the Intel burn test or whatever.
 
If I tried running Valley and Prime95 at the same time I'd probably boil the water and scald myself when the whole system exploded under my desk. 

This is great info and should be linked in the Mods Rigs sticky or here. 

What is blue ribbon?
 
edit: nm, I searched and read up on it. Thanks for the nomination!

Cool GTX
 
I could add an additional 240 rad to the existing unit instead of full custom

I think it's brilliant how Swiftech has blurred the lines. You've got your true AIO systems like the Corsair or whatever where they tell you in no uncertain terms to leave it as is, and you know it probably wouldn't have the capacity to add anything to it anyways, either the pump is too weak, or the radiator too small, or both. Swiftech actually used a powerful enough pump, and a capable enough radiator, that they advertize it as being expandable.
 
When I first installed mine the hoses weren't long enough to reach from the cpu to where I needed to put the radiator in my case. I'd bought some extra tubing, so I removed the original tubing and fit my own tubing between the cpu plate and the radiator unit. Now that I've added my gpu block, I cut into one of the lines and re-routed the water through the gpu block to the cpu block and back to the radiator. At what point is this no longer an all-in-one unit and instead a custom loop? I'd say it already is a custom loop. The only difference between my custom loop and others is that I don't have a separate reservoir and pump. Once I add my two 2x180 radiators into the loop it'll be even more custom, yet still based on the Swiftech rad/pump combo.
 
So yeah, if your case will allow it, just get some tubing, the appropriate barb fittings, and another radiator and splice it in to your loop if you want to. You should be able to drop your loop temperature another 20 C under that load, and it would be easy peasy to do it.