XPS 8700, installed GeForce GTX 960, no boot

I also noticed there is an on board graphics card I think, there is an HDMI port on the motherboard, but in device manager it only shows my 660 card. Is there a way to disable this on board gpu?

My XPS 8700 is Intel Core i7 - 4770 CPU @ 3.40GHz, 32 gigs ram, 64 bit OS, power supply model: H460AD-00 Max out put power: 460W. GPU 660 GTX (Apparently only needs 400W power).

-The Dell XPS 8700 is the comp I want to put the GeForce GTX 960 card in. It currently has stock a 660 GTX.

The comp I took the GTX 960 card from specs is AMD Phenom II X6 1090 T Processor 3.20 GHz, 8 gigs of ram, 64 bit OS. Power Supply Sea Sonic SS-500HT, Max out put power 500W, GPU: GeForce GTX 960.

Both GPU's work fine when in their default comp, but when I put the GTX 960 into the XPS 8700, it won't boot. Power is connected, 660 is disabled in device manager, Bios updated, cmos cleared. I am thinking next to try reinstalling windows, maybe the drivers from the 660 are causes a conflict... Could it be the power supply? Dunno. Any suggestions would be much appreciated! Tips hat*

Thank you, awesome answer, I will order a better power supply and see if that fixes it. I will post back with my results. Thanks again.

There were several BIOS updates required before some cards work.

Your case sounds more like secure boot needs to be OFF and CSM on.

https://nvidia.custhelp.com/app/answers/detail/a_id/3156/

Thanks for advice, upgrading the power supply worked, So 500W should work for it, but I just went up to 750W for future use.

Thanks again!

I was running a MSI branded GTX 960 in my XPS 8700 for over 2 years before reinstalling the MSI Radeon 7770 GHz edition (my first upgrade from the 1GB GDDR5 AMD (Dell OEM) 7570. With the OEM PSU, as well as a i7-4790K, as Dell released a BIOS update for unlocked CPU's. Would later install that GPU in a rebuild of a Dimension 2400, which is a lot easier than many here has stated, using a mATX MB. No case mods needed, other than removing those CPU retainers that looks like standoffs & the ugly green shroud that used one fan to cool both CPU & exhaust hot air. 

However, there was no issue with the GTX 960 in the XPS 8700, even overclocked a little with MSI Afterburner. My suspicion is that your OEM PSU may be beginning to fail. I had to replace mine later due to freezing that would take place, there would be no BSOD, the system would freeze in place & therefore, there was no file created (other than shutdown issue from pressing the power button) to determine issue. So I upgraded to a EVGA B3 550, which was a nice step above the OEM PSU & 2x as heavy. Plus being small, a perfect fit. Just had to press in those two tabs (or humps) revealed once the OEM PSU was removed for it to go in, can be done with a finger, the metal there is thin. These units can be found often on promo at Newegg or sometime EVGA themselves. 

https://www.newegg.com/evga-550-b3-220-b3-0550-v1-550w/p/N82E16817438120

There's also the option for $20 more for the Gold rated model, of which I have 5 in use & 2 still sealed (four 550W & three 650W). Three are the Bronze above & the other 4 are Gold rated. All were purchased on promo & most has a $20 rebate. 

https://www.newegg.com/evga-g3-series-220-g3-0550-y1-550w/p/N82E16817438095

We had a long discussion (30+ page) on the issue here, many were running the GTX 970 with the Dell supplied GPU. The issue wasn't the PSU, rather both the faults of NVIDIA & Dell not upgrading firmware so that it could run. Many of those in the discussion had upgraded their PSU to no avail & this disclosed there was a huge problem with many XPS 8700 owners, some returning their PC's within the 30 day timeframe. 

In the end, both parties upgraded firmware so that the GTX 970 would run in the XPS 8700 (with the native PSU). 

Bottom line, the GTX 960 is UEFI ready, so that's no issue, the only thing I can see is a dying PSU. These doesn't last forever & OEM units often less due to cost cutting measures. This is why these are so light in weight upon removal, a quality model will simply feel heavier. Plus one cannot go wrong with the EVGA brand, especially this model, perfect size to upgrade mini towers going back to the pre-Intel 'i' series or Phenom days. 

Good Luck!

Cat

BTW, there's a huge chance that the GTX 660 isn't UEFI ready, why it likely needs a BIOS flash (as did my MSI Radeon 7770) to run in UEFI mode. You can switch to CSM to run the GTX 660, but this may mean that you'd have to reinstall in legacy MBR mode. Better to get the BIOS update. 

Here's a discussion about the issue, however the GTX 960 is the clear winner of the two & UEFI ready out of the box. I have a collection of GTX 660/670 models in usage in AMD FX systems, plus a GTX 770 4GB GDDR5 Classified in an i5 system. The 960 is a better performer then the GTX 600 series & can do 4K at 60Hz with it's Displayport 1.2 port. 

https://forums.evga.com/UEFI-BIOS-for-GTX-660-m2040706.aspx

There's also a firmware patch for (most of) of the GTX 900-1000 lineup, which improves Displayport performance, it upgraded my GTX 960 successfully, as well as GTX 1060/1070 cards. Displayport is faster than HDMI. Even the older DP version 1.2, which the GTX 900 series has, is faster than HDMI 2.0. So there must be some benefit to the 900 series cards to install the patch. Once done, it'll show the update is successful, or doesn't apply to the card. No damage is done either way. 

https://old.reddit.com/r/nvidia/comments/8oxeh2/display_port_firmware_update/

Cat

I have had a gtx 970ME running on stock PSU for 2 years now w no issues, just to offer another experience for other owners/readers

There were several Bios Updates.

Secure Boot Must be OFF for Non Dell cards.

@speedstep, you may very well be right about disabling Secure Boot for the non-Dell models.

Being it was among the first items I disabled once booted up & updated, and have had three retail cards in my XPS 8700 (MSI Radeon 7770 GHz Edition, MSI GTX 960 & EVGA 6GB 1060 SSC, I can't confirm if Secure Boot would had made a difference. 

Although just as you posted, there were other Topics (one very long GTX 970 discussion that could fill a book) on this site concerning aftermarket cards & Secure Boot. The only way I'll find out would be to dig it out (have a dozen PC's), enable Secure Boot & cross my fingers. Still may not boot due to a couple of unsigned drivers, one to improve the Realtek audio that hasn't been officially updated since 2017, installed some that were tweaked from that last driver. Also a tweaked Intel Rapid Storage Technology driver for better SATA performance, as newer official ones are incompatible with the Intel Z87/97 chipsets. 

Cat