Aurora R9, ram incompatibility with 2 identical sticks?!

Likely not the same sticks. If you mix and match you usually end up with ram incompatibilities. You can try manually setting the lowest common timings, but even that does not guarantee it will work.

You can try the new stick by itself to ensure it works standalone in the current slot. If it works then you know what the issue is.

If you use 2 sticks it's best to get a 2 stick matched kit, to avoid this issue.

I would also do some cable management to increase air flow. 

they are both the same sticks. A singular stick will work fine in the 4th slot. I will fix the cables this weekend when i put in my SSD.

Yes, they might be but they might actually not be exactly the same electronic wise. Manufacturers source various ram chips from vendors like micron, samsung, etc.. and use them based on availability and revision of memory chips.

You might have a stick with Micron memory on it, and another stick with Samsung memory in it, and they might both be marketed as identical sticks with identical timings in identical packages. But in reality they are not identical.

That's why you normally buy dual or quad channel kits, because those are guaranteed to all have been manufactured with identical chips.

If you use cpu-z and read out the spd information it might show you in more detail. Typically they have serial numbers imbedded in the SPD. If the serial numbers are far apart they will have been manufactured at different times, possible with different memory chips or revisions of memory chips.

If you buy a 16gb stick in march and come back in december and buy a second 16gb stick from the same retailer they aren't matched.  Especially the longer the gap the manufacturer is more likely to have different manufacturing revisions.

If they both work individually try disabling xmp and running them in separate one black one white channel. 

you guys both had a good point, but I managed to borrow two sticks of my buddies 64gb kit (16 x2) and they didn't work in any combination either.  @r72019 @Vanadiel   These all came in the same set btw.

A thing you could try it resetting the bios to default settings and see if that helps.

Can you get to the bios screen when 2 sticks are in?

Another option, if you can, is run memtest from a bootable USB stick, to see if that can detect something obvious.

You could also try a complete cold reboot by unplugging the power supply power cable, to ensure there's no standby voltages left. You normally would turn off the power supply prior to working inside your case, but sometimes pc's get shut down and people forget to take that extra step.

You can try clearing CMOS and also be sure to also discharge flea power from the PSU by holding down the power button before touching anything in the PC.  It often helps to clear CMOS before booting with a new RAM configuration. 

@r72019 @Vanadiel  well I reset CMOS and bios and tried all the different ram slot possibilities. SLOT 1 doesn't detect any ram. currently I have them in slots 1 and 4 and its only detecting slot 4. Slots 2 and 4 didn't work even after everything you guys suggested. Any last resort tips?

Hello,

Just chiming in with a question, did you test a working single ram alone in each of the four slots? 

- if all slots are failing, you can return the ram chip

- if some slots fail and some pass, reseat and recheck the fails

- if all are working - you can proceed to test exact pairs

I noticed Patriot's warning about their own sets not being guaranteed to work together...

which highlights their, shall we say, high degree of selectivity in functioning properly in some motherboards.

If you add that to the fact that Dell does not approve them for use in the R9...

I'm amazed you got the one RAM module to function.  I think you have an uphill fight to get the second module to work, these motherboards are not at all easy to deal with in regards to adding RAM.  Some folks have reported success with other brands of RAM, but the undertaking may drive you crazy.

My own adventure with my R9 and RAM went well, but I went back over all the forum post to find those that had reported the least problems with RAM upgrades and purchased what I hoped would be a compatible configuration...

Best of luck in your RAM endeavors

Can you put just the new stick in by itself, enter the bios, and manually set the settings instead of using the XMP profile? It might not apply the XMP profile properly. Pay close attention to the voltage and ensure it is set to what the memory module requires. Might be 1.25, might be 1.35 volts. Be very careful with that. I have seen strange behavior in the past with that, sometimes applying an incorrect XMP profile.

If you set all the settings manually to the manufacturer listed settings for that memory, it should work fine.

If it does not, than you might have run into memory incompatibility issues with your motherboard. I have been building my own pc's for over 25 years, and why I personally have never ran into memory being incompatible with a motherboard, I have heard about it. 

Actually, with my previous build last year one of the sticks in my dual memory kit was faulty, and the motherboard would see the stick but windows would not see the memory capacity associated with it. Everything worked without a hitch, but my memory under windows was 50% of what it should have been. Took me a while to figure it out, because the bios listed the correct memory size and I did not even realize until days later that I was running on 8 instead of 16 gigabyte. And that was only because I could not reach the performance I should have had and started to look around why. Exchanged the kit and problem solved.

Well they didnt work even with the xpm turned off in bios Im also getting memory management BSOD and not sure what to do lol

Does each stick individually work?

yessir