Nice !

What is the stock cooler you have on your 8900? My stock cooler looks similar to your new cooler.

That's interesting. Which CPU did you get and when? I have the i7 6700 and got mine last September.

Look at the video, my stock cooler is shown at the 1 minute mark and again at 3:45..

I wonder if all the newer 8900s are getting your cooler or if it only goes on the Core i7 6700k CPU.  Your cooler looks similar to the one Dell put on my old Core i7 920.  It's pretty decent.  The one that came on my Core i7 6700 is wimpy and IMO inadequate, causing thermal throttling of the clock rate.  

Interestingly enough I just looked in the service manual and your cooler is what they have pictured there.

Great video and creative install!!

Those are nice temps and I wouldn't worry about temps even into the mid 70's under load, that CPU can handle that without breaking a sweat.  How is the physical stability of that cooler since it's on its side when the machine is upright?  Does it move side to side much?

What display are u running with the GTX 1070?

I tried a similar upright cooler in an XPS 8500 with a GTX 1080 using a 34" display, but that cooler had a 92mm fan.  Nice to see you can run a 120mm fan cooler in that space that's limited by height of the case and the location of the RAM sticks.   When I installed the Zalman cooler it did great at idle and moderate loads, but under heavy loads at higher resolutions (The Witcher 3 at 3440 x 1440 ultra settings) the cooler wasn't able to keep up with the heat and the CPU would hit 80+ degrees.  The stability of that cooler worried me as well as the mounting system wasn't that secure given the height of the cooler.  It did "wiggle" a little when I moved it from side to side....

 At 1920 x 1080 on a 28" display, CPU temps were never a problem playing the same game with a GTX 660ti and never went above 55 degrees with the stock cooler.  Once I changed to the 34" display and the GTX 1080 started pushing higher frame rates, the CPU temps got really out of hand under heavy loads because of the lack of ventilation in the case design and the conservative fan curves of the motherboard fan headers. That was even with a 120mm front intake fan..

@HanoverB

Yes that is the stock cooler that came with my machine. I do however have a 6700k processor so maybe that is the reason why dell changed it. The extra fans are wonderful as my processor temps hover at 70-73° at full load while the GPU is running at full steam with temperature at a constant 70°. My SSD and HDD are at constant 33° after a few minutes of the GPU running at full speed. I think changing the stock exhaust to a higher CFM fan really helps a lot in getting rid of the heat and the 2 intakes I have at the front is just icing in the cake. If I put my hand behind the PC I can really feel the a lot of heat coming out were as from the stock setup I only feel little heat being pulled out of the case.

One thing I changed on my setup is took out the pci fan and just placed a more robust fan controller and I did not see any temperature change.

I think even if the 1070 or 1080 puts out less heat than the 980ti the stock exhaust fans of the XPS needs to be changed and at least 1 intake fan needs to be added in then it will not make you change the stock processor cooler at all.

@creampie

That pix is of the stock cooler that came with the 6700?   Never knew Dell used anything other than the stock aluminum CPU coolers in these XPS machines.  That's a nice setup with the 980ti Strix and the additional fans, how's it do at keeping CPU temps manageable?

@HanoverB

The H7 doesn't weigh a whole lot. Plus I'm reusing the sturdy, stock, STEEL backplate that is fastened not only by the 4 cooler mounting screws but also the three CPU retention bracket screws.  That combined with the lower profile cooler (relatively smaller lever moment vs. other 120mm solutions) provides a very sturdy physical connection with no wobble at all and in fact when I was reinstalling the motherboard I picked it up using the heatsink as a "handle" because I felt that was the most secure way to maneuver it around in the case.  I have no worries about it sagging or stressing the motherboard when hanging sideways under its own weight.

I run a 24" 1080p Acer GN246HL 144Hz screen with 3D vision which is also new.  The 1070 should allow me to get close to 60Hz per eye (120Hz total frame rate) in a lot of titles, at the native 1080p.  Looking forward to playing with it - I don't get much gaming time these days but the upgrades (and an 850 EVO that I put in on day 1) have made the machine a dream to use when I do.

Next up is a new PSU and maybe an intake fan.  It probably doesn't need either but I came this far so what the heck, right?  I'm thinking about the EVGA GQ series, either 650 or 750 watts.  They are about the same price (and size) and the 750 watt unit would future proof me if I ever swap case/mobo and do SLI in the future.  Total overkill for this box, I realize...

I took the front off the case last night and it seems there are two diagonally-positioned mounting flanges with holes that look to be spaced for a 92mm intake fan.  The only question is how to power it...

Thank you for that info on the stability of the cooler.  

With those temps u probably wouldn't need a front intake fan.  I put a 120mm fan up front using radiator brackets.   I am sure a 140mm fan would work with the same brackets and would do that if I didn't have the Sea Hawk fan up there.  With the single intake fan I ran it to a 12v molex using a 3 pin adapter..  You want a large, slow moving fan as the intake fan if possible.  There is a picture of the 120mm fan here on this post....there is also a pix of the 140mm fan filter in place.  They make the brackets in a 140mm so thinking that SHOULD work as well....

http://en.community.dell.com/support-forums/desktop/f/3515/t/19985691

So how are CPU temps with the system at full load and the warm air from the GTX 1070 thrown into the mix?

@creamiepie

Good info on the temps and the controller.  I see a lot of succesful GPU installs being posted without follow up performance/temp readings.  Your past posts have been helpful in making changes to my XPS 8500.  Thank you.

Really good info, @creamiepie.  I was thinking about getting one of those y-adapters and also wondering if the 3-pin header was voltage-controlled by the mobo/BIOS or not.  You answered both before I could even ask :-)

Does your 88CFM exhaust fan stop running when the computer goes to sleep?  Or do the molex plugs get 12V at all times?

What I want is a front fan that only runs fast when the case temps get high so I am going to try a 92mm Arctic Cooling F9 TC.  It has its own internal controller and thermocouple that you can place anywhere within 40cm of the fan.  I guess I'll power it off a molex adapter.  My only concern is if that fan will power down when the machine sleeps.

I also ordered the 650W EVGA GQ PSU.

Does the bios in the XPS 8700 or the XPS 8900 give you any control over the settings of  the 3 pin voltage regulated or 4 pin PWM motherboard fan headers?  

The XPS 8500 bios does not allow any changes to the fan curve of those headers.

Does the bios in the XPS 8700 or the XPS 8900 give you any control over the settings of  the 3 pin voltage regulated or 4 pin PWM motherboard fan headers?

IIRC, using speedfan 4.51, I had no luck changing the fan profiles on the 8700.

I picked up an NZXT Grid v2 fan controller but never installed it.

Instead, I cut a hole in the front of the case, added a 120mm fan on a Y-splitter with the exhaust fan and it runs fine. 

I also removed the extra PCI blanks to give the graphics card heat a way out and the combination of the extra intake with the ease of exit helped a ton with temps.