How can I determine graphics card compatibility with Aurora R3?

Excellent, thanks!  Out of curiosity, what makes the GTX1080Ti different such that it would have to be a single-card installation on my desktop?

This is related to a power limitation. I double checked with engineering and looks like your PSU (875W) will be able to handle it, but again, this is not officially validated. 

a.I have an Alienware Aurora R3 from 2010 which is currently using 2x GTX 460 graphics cards in an SLI rig. 

b. I'm looking specifically at the GTX 750 Ti with 4GB vRAM [amazon product link] or the GTX 1050 Ti SSC with 4GB vRAM [amazon product link] (although the factory overclocking in the linked 1050 Ti makes me a little nervous).

My questions:
1. What's the most reliable way to check that a given graphics card will be compatible with my Aurora R3 (in particular, the MoBo and the PSU)?
2. Will either/both of the cards linked above work?
3. Is a single newer gen graphics card likely to out-perform two GTX 460s? If not, would I be better off trying to replace the faulty 460 and have my full SLI rig up and running again instead of buying a newer card?
4. Would my SLI bridge support two newer graphics cards, or is SLI specific to a given card?

a. Sounds like maybe an Aurora-R1. What Intel processor is installed?

Note warnings posted here:

Help me upgrade GPU in my 5 year old Aurora R3 

Buy from somewhere you can return it. The Aurora-R3 can get very temperamental with upgrades or in general ( lucky you have a working one).

b. I suggest a GTX-10x0 card. Can you afford a 1060 or 1070? I got a MSI Gaming-X (factory-OC possible) but I run it at stock-clocks.

1. Try it. Return it if it doesn't work.

2. 1050 or 1060 would be better

3. There are websites that compare "horse-power" of cards. You want a single card (and it's ok if it takes-up 2 slots itself). No SLI is needed (skip those headaches)

4. I think 1070 is smallest card that supports SLI. SLI bridge is different (better) now. But as posted above, you DO NOT want SLI. Get ONE nice card. Get a 1080 or 1080ti if budget allows (but that's a lot of money to invest into an old machine that can break down at any moment).

CPU is Intel(R) Core(TM) i7-2600K CPU @ 3.40GHz.  The model definitely says Aurora R3 in BIOS and OS system info.

Ok, right ... Aurora-R3. No problem. Everything I posted still applies.

So, what is your budget and what are you liking?

The 1050TI  4gig card is Great for most systems.

Hellblade Senua's Sacrifice GTX 1050 Ti vs. GTX 1060 vs. GTX 1070 vs. GTX 1080 - YouTube

GTX1050  or 1050TI  and  GTX1060 DO NOT SUPPORT SLI so they would not be DUAL.

You need 1070 or 1080 or TITAN X for SLI (DUAL)  TITAN X would need at least 1100W power supply as the TDP is 225W or more PER CARD. 

Amazon.com: ZOTAC GeForce GTX 1050 Ti Mini, 4GB GDDR5 DisplayPort 128-bit Gaming Graphic Card (ZT-P10510A-10L): Computer…   $160

Amazon.com: MSI GTX 1060 6G OCV1 Graphic Cards: Computers & Accessories   $280

Amazon.com: Gigabyte GeForce GTX 1070 Mini ITX OC 8GB GDDR5 Graphics Cards GV-N1070IXOC-8GD: Computers & Accessories  $482

Amazon.com: MSI Gaming GeForce GTX 1080 8GB GDDR5X SLI DirectX 12 VR Ready Graphics Card (GTX 1080 ARMOR 8G OC): Compute…  $548

My budget for this upgrade is less than $200... this is an old rig, and I'm probably going to need a new one in the next few years anyway.  I don't want to spend a fortune on an upgrade component, but I also don't want to buy something that's already totally obsolete.  I decided to go with the GTX 1050 Ti from Newegg [GIGABYTE GeForce GTX 1050 Ti DirectX 12 GV-N105TG1 GAMING-4GD 4GB 128-Bit GDDR5 PCI Express 3.0 x16 ATX Video Card - New… ] because it offers 4GB vRAM in accordance with nvidia's reference design, has two fans, multiple HDMI outputs, and a nice backplate. I'll update with my experience after it arrives and I give it a whirl.

I have the aforementioned Zotac unit and its fine for all of my games whether using MAC OS Sierra or Windows 10.

All games Running 1900 x 1080

This card is as good as the GTX 680 classified card it replaced and its about 8 to 30 percent faster with less than half the power use.

DVI should work. I wonder which port is #1 or Primary?

Try the other PCIe power-cable (directly to card).

Were you switching to the proper Input port-type at the monitor itself? 

Does computer appear to be booting (even with no video). Meaning HDD light is flashing, etc.?

The GTX 1050 Ti arrived last night and I gave it a whirl... and my two test displays reported 'no signal'.  The first test display is a Sharp TV from 2013 (Sharp Aquos Quattron+ LC-60SQ15U) which accepts VGA and HDMI inputs.  I couldn't try the VGA, but from what I've read the nvidia Pascal arch doesn't include a DAC and therefore will no longer support analog display technologies anyway (without involving an expensive external signal converter).  The HDMI connection was directly from PC to TV, and resulted in a blank screen.  This persisted even after I rebooted the PC with the HDMI connection already made to help ensure the HDMI handshake process worked.  The second test display was the Alienware monitor that came with my Aurora R3, from 2010 (Alienware AW2210t).  For this connection I tried a simple DVI cable directly between PC and monitor, and saw only 'no signal'.  

Two questions come to mind:

1. Am I correct in assuming that the TV and monitor should be capable of handling a digital video signal since they have HDMI and DVI inputs, respectively?

2. How can I debug this situation without being able to see BIOS settings and/or hardware test results?  I don't think the new 1050 Ti will physically fit in the case alongside one of the old 460 units, and AFAIK the Aurora R3 with stock Alienware 046MHW version A00 motherboard doesn't have on-board graphics output of any kind.

I'll try simply re-seating the GPU tonight 

The PC does seem to be booting (lights and fans, as per usual start-up sequence)

I tried switching between input ports on the monitor, but both auto-detection of DVI and manual selection of DVI resulted in 'no signal'.

It's interesting that you mention using the other PCIe power cable -- one of the factors in my decision to upgrade cards was that one of my old 460 GPUs was failing hardware tests and seemed to be causing intermittent crashes; I wonder if the GPU itself was not faulty, but rather the power cable leading to it?  I'll try the other cable tonight before re-seating the card to cut down on variables.

If the R3 has UEFI bios you must Set Secure Boot OFF and Legacy Option Roms and CSM to ON.

When installing an after-market graphics card into a certified Windows 8 PC with UEFI enabled, the system may not boot. … 

The only other issue is if somehow the card does not go all the way down into the slot.

I actually use an HDMI to VGA adapter so that I can split off analog audio and vga video.  I still prefer this to HDMI or DVI because I can set Gamma in my games with analog video.

http://www.belkin.com/us/p/P-B2B137/ 

The PC is definitely booting and the GTX 1050 Ti is definitely receiving power (lights come on in the Gigabyte name, and fans spin for a few seconds during boot).  I tried switching the power cables (between P15 and P14) and both appeared to work equally well, but the monitor (an Alienware AW2210t) still reported no signal on both DVI and HDMI.  I tried re-seating the card several times, moving it to the other GPU PCIe slot on the MoBo and trying each of the HDMI outputs both as hot-swap and connected-at-boot handshake configurations -- 'no signal' st the monitor in all cases, and no joy. 

Am I likely looking a lemon GPU at this point, or is there more I can do to debug the situation?  My next thought was to plug the old 460 back in so I can see the BIOS settings and make sure nothing there is odd and possibly getting in the way of the 1050.  

Interesting, I'll have to connect the old 460 GPU so I can see the BIOS settings and ensure this isn't the problem.  I'm running Ubuntu 16.04 and Windows 7, so it wouldn't be anything Windows 8+ specific. 

>>I actually use an HDMI to VGA adapter so that I can split off analog audio and vga video

I read that the Pascal arch doesn't output an analog signal... are you using an active signal converter, or just an adapter?