fegleader
I recently buy and EVGA RTX 2070 black edition , i installed In the Amplifier And when its Power on just at the starting Windows the computer freezes and after a minute
Reacts for a While and freezes again and so on

I currently have an Alienware x51 R3 , does anyone know which EVGA rtx series cards are compatible with the Alienware Grpahics Amp?

I would like to Know if it is and issue of compatibility or it’s just a Graphics card failure

If anyone could help me it would be greatly appreciated - Thanks

Don't believe there's compatibility issues.  I checked here and see your GPU is compatible with the Alienware Graphics Amp.

Have you checked to see if the GPU is sitting well into it's PCIe slot and the power connectors snapped in?  If all is well there,  I would still check the temps, if possible though windows just in case it might be temp related or a cable or GPU driver related.

Make sure all your connection pins are clean.
I don't know if Alienware uses a proprietary adapter or uses a thunderbolt cable.
But I can say, if the connection between card and PCIE lane gets interrupted (could be through the connection cable) then you could get system freezes.
Try out with a cheap graphics card, if the above solution is too expensive.
You can find GT graphics cards on the cheap on second hand sites.

fegleader
 
the final conclusión at all is that the EVGA RTX2070 Black edition is Not compatible with the Alienware Graphics Amplifier

It actually is though.  It's listed in this link from my last post.

I have exclusively and extensively searched for compatibility of EVGA 20 series graphics cards with alienware graphics amplifier.
I am sure there are many answers to this issue and there is no wrong or right, so I will simply state how I got mine to work.
I hope this helps others because after extensive googling I did not find anything conclusive and I believe something like this
would have helped me.
 
Firstly specifications:
I had Dell Alienware 15 R2 with an internal GPU: GTX 965M. It had driver 440.97 installed through ge-force experience.
I had bought EVGA 2070 Super XC ULTRA (2.75" slot) that won't even physically fit into the amplifier. So I had to use a pcie 3.0 16 slot riser
cable. 
 
Since I had updated drivers I expected a plug and play. So I verify the power connections, use the proprietary cable to plug it in.
It detects the GA has been connected  and asks for a restart. I do so and it boots upto windows10 but it still shows the internal gpu and alienware
control centre automatially pops up the same message asking for a restart. I do this a number of times but with no progress.
 
Then I came across a post saying the alienware GA has 3 power connectors (P1- connected to the board, P2 and P3 for the card).
I had to plug P2 to the 8 pin and P3 to the 6 pin (I had it opposite initially). Then I hit the reboot loop problem.... It will boot and restart.
 
Then I updated the bios and graphics amplifier driver to the latest from dell. This would help resolve the boot loop and I successfully boot to windows.
The internal gpu for the first time shows offline and external gpu online in the dell alienware command centre.Then I hit microsoft basic display adapter issue, where instead of nvidia rtx 2070 super it shows it is a microsoft basic display adapter. I read it may be a driver issue, but as I mentioned above
I had the latest installed!
 
So, anyway, I came across a post where there is a bug and some dell representative asked to install the driver after plugging in the eGPU.
So on top of what I had, with my eGPU connected I downloaded and installed the desktop version of the driver from nvidia for 2070 cards, v440.97.
 
I restart and FINALLY SUCCESS! My card gets detected as RTX 2070 SUPER. I even got to over-clock with precision X1.
I hope this helps people out there!
 
Best,
Srijit