If yoçur CPU supports 128GB then it is worth confirming the MB limit, I cannot confirm for you, my R8 said max 64GB, a limit that has existed now until the last R11/10 who have announced finally up to 128GB.

I think the chances are very slim to accomodate 128GB on an R7. Still, we can keep an open mind and see if anyone has tried

You can check your CPU limit on Intel sites before checking MB limits.

I have not tested, but my R8 was limited to 64GB too although the i9-9900k can address 128GB.

Very interesting  2933Mhz RAM with 2x32GB = 64GB and 2 slots free. Do they have a moneyback guarantee?

Worth a try, but let's call the vets here @Tesla1856 , @r72019 and @Anonymous 

so if my cpu supports up to 128gb this means the whole system supports 128gb ? (i see now on intels website my cpu too supports up to 128gb)

https://ark.intel.com/content/www/us/en/ark/products/126686/intel-core-i7-8700-processor-12m-cache-up-to-4-60-ghz.html

did you put 128gb in your aurora since the cpu supports it ? cheers

good but what about the site i quoted above that says max ram is 128gb ? you think they are wrong ?

https://www.compuram.biz/memory/dell/desktop-workstation/alienware/series/aurora-r7/?st=tab_maxmem

cheers

Z370 only supports 64GB (absent a BIOs update which is not available).  Even for third party boards I believe updates for 128GB were only offered starting with z390. You will see 128, but only be able to use 64. The remainder will be hardware reserved.

Also, some others have unsuccessfully tried on the R7. 

Yeah, the R7 and R8 are both on z370, they are essentially the same (except the R8 got the rev2 version of the z370 board to support 9th gen like your 9900K). 

I don't know anything beyond what is posted in Aurora-R7 PDF Service Manual. But since I was summoned here, I'll post my thoughts.

First, we know that (usually) as you approach the system's MAX installed memory, it has to run a bit slower. So, if you have all that memory installed, but not actually using it, it's not really a benefit.

Second, I truly wonder what apps people are running to need this much memory on a gaming machine.

Finally, 16gb should be fine for 90% of use-cases. If I wanted "a lot of memory" on a WinTel system, then 32gb of name-brand high-quality (full MB speed) Dual-channel would be my limit. If I wanted 64gb or 128gb it would be ECC memory on a system that could handle it.

If you are running hyper v and virtual machines it makes sense.

Otherwise its diminishing returns past 16 gigs.