Question B450-A Pro Max not allowing all 4 sticks of ram?

[eqiz]

In picture it detects all 4 sticks of ram but why only 16gb usable? Also I was told I need to enable A-XMP for 3000 mhz support, and it still only showing 2133?

 

[cherry blossoms]

Supported official memory configs 2700X I believe:

Memory Configurations
Dual Channel	Single Rank	2 of 2	DDR4-2933*
2 of 4	DDR4-2933*
4 of 4	DDR4-2133
Double Rank	2 of 2	DDR4-2667
2 of 4	DDR4-2400
4 of 4	DDR4-1866

• * - 2933 MT/s on motherboards with at least six PCB layers only, otherwise 2667 MT/s (four-layer boards).

Check with your motherboard manufacturer QVL for your exact memory model.
If not listed, it either wasn't tested, or failed testing.

Not all x2 modules will behave in a x4 config.

I would guess you might be able to overclock in a x2 config. I a x4 config will probably have to tweak manually.

 

[eqiz]

I'm not following... so I have to get a completely different motherboard and RAM? Things different these days? Use to just look up see if mother board supports RAM.. this motherboard suppose to support up to 64 gb of ram.. it can support 3000 ram.. so why can't I run 4x8gb of ram for 32gb? it has 4 slots?

Why can't I use 4x8gb of 2 of Corsair Vengeance LPX 16GB (2x8GB) DDR4 DRAM 3200MHz C16

 

[Calvin7]

Memory is guaranteed in the form sold. Corsair as well as other memory manufacturers don't guarantee compatibility when using more than one kit of memory.

The memory configurations chart for that CPU shows officially supported memory speeds dropping when using more than one DIMM per channel. B450-A Pro Max is a dual channel memory motherboard. It shows 2933MHz being supported using two modules.

 

[eqiz]

Ok that makes more sense, but it shows it should be able to use 4 channels right? so how come it can't use 2133 with 32gb of memory? It is only allowing for 16gb

 

[cherry blossoms]

As indicated above, not all memory will be supported in a x4 configuration vs a x2 configuration., especially if not purchased as a x4 kit.

Your exact memory model number was not seen on the MSI QVL. for your motherboard.
SOME Corsair kits listed on the QVL as x4 compatible, others ONLY x2.
A x4 setup is much more work on the memory controller.
Even a specific MODEL number may not always be an exact science, as memory manufacturer may change in REVISION numbers, which entails subtle differences in voltage and timings. These differences can appear in lot to lot variations from the same manufacturer as well

Your best bets to try to get it all to work together:
1.Individually test the memory in x2 configs, make sure it all works in that mode before trying to go to x4.
2.See if a BIOS update is available for memory support. From the date on your picture, it appears you have the last BIOS that mentions memory compatibility however.
3.You can try manually setting memory timings and voltage.

 

[Calvin7]

You can make any combinations you want, but memory manufacturers won't guarantee multiple kits will work together.

This is a Corsair Vengeance LPX 32GB (4 x 8GB) 2133MHz kit:
https://www.amazon.com/Corsair-Vengeance-2133MHz-PC4-17000-Systems/dp/B00PLER4HW

 

[eqiz]

Ok so there are 'kits' these days and I got to pay a lot of attention to timings and setups... all good to know now very appreciate the level of detail and trying to 'dumb' it down for me. I had to look up QVL wasn't familiar with that. I came to a website that did some comparisons is there a better reputable one? For example for my motherboard I found this... https://pcpartpicker.com/products/memory/?compatible_with=XJbCmG on the listing it shows
Corsair Vengeance RGB Pro 32 GB running at 3200 ... so this means I could get that exact RAM and I can get the 3200 or at least 3000 with that motherboard / memory setup? Am I undertanding this correctly?