I have a ryzen threadripper 1950x and a ASUS ROG Zenith extreme board. I have been troubleshooting for about a day and a half. I updated my bios to the latest publicly available 2001 and my motherboard/processor combo only recognizes up to 64 GB of ram. Current RAM I am using is G.SKILL F4-3200c16Q2-128GTZKW. My goal is to run all 128GB at the specified 3200MHZ speed. However I can only get 6 sticks to be boot and only 4 of the 6 are recognized by the MOBO. I run speccy and it shows all 6 sticks present. Any help is appreciated.
This is your motherboard's QVL List for RAM Memory for 3200Mhz. but it is 3 years old so your RAM is not listed. But read what it says about where to install the RAM Memory on the Motherboard's slots: ROG ZENITH EXTREME Memory / Device Support | Motherboards | ASUS USA
I have attached both QVL lists for RAM Memory to this reply for you to download if interested.
EDIT: Looking at the QVL list for RAM over 3000 Mhz everyone is only supported on 4 Memory slots being populated. None for 6 slots. RAM with less than 3000 Mhz have some that are compatible with 6 Memory slots be populated.
I suggest you open a Asus "Live Chat" Support ticket and ask if your motherboard supports RAM modules of over 3000 Mhz on all 6 Memory slots. That could be why only 4 Memory slots are being recognized and not 6 Memory slots.
So... i did some extensive testing with my memory. It turns out that 3 of the 8 sticks are bad. Moving on from that issue, i cannot get my board to boot with four sticks in with "XMP" active. Sticks are in the grey recommended slots. Board reboots several times until it posts stating ram speed was changed due to failure to boot. When i activate "XMP" it shows the proper timings. Both mobo and processor show they support this speed of ram. One caveat to that is for board it says 3200(O.C.) does that mean i have to have my bios set to O.C. mode?