[SOLVED] Adding RAM

[The_Ginja_Ninja]

Hi,

I currently have 2 x 8GB Corsair Vengeance LPX 3600 C18. It is installed in slots 1 and 3 as recommended for my motherboard (MSI X570 Tomahawk).

I have just ordered 2 x 16GB Corsair Vengeance LPX 3600 C18.

Can I add the new 2x16s to my existing 2x8, given they are same speed and latency, only different sizes?

If so, which of the below configs should I use:
1 - 8GB, 2 - 16GB, 3 - 8GB, 4 - 16GB
1 - 16GB, 2 - 16 GB, 3 - 8GB, 4 - 8GB

If not, then I'll simply replace the 2x8 with the new 2x16.

Thanks

 

[DMAN999]

They probably won't work with all 4 (2 different kits of different sizes) installed BUT it won't hurt to try.
Just be aware that with 4 sticks installed they will NOT run at 3600, they will probably only run at 2666, 2866 or possibly 2933.

∙ Supports 1DPC 1R max speed 4600 MHZ
∙ Supports 1DPC 2R max speed 3866 MHZ
∙ Supports 2DPC 1R max speed 4000 MHZ
∙ Supports 2DPC 2R max speed 3600 MHZ

from page 15 of your manual.

First go into the BIOS and set Optimized Defaults and save and exit.
That will reset your RAM settings to stock 2133 or 2400 (depending on your RAM kit)

Then,
I would first leave the 2 8GB sticks in slots A2 and B2 (2nd and 4th from the CPU) and add the16 GB sticks to slots A1 and B1 (1st and 3rd from the CPU).
If that doesn't work try switch the 8 GB to A1 and B1 and 16 GB sticks to A2 and B2.
RAM placement is shown on page 5 of your manual:
E7C84v1.1.pdf (msi.com)

If neither config works just try the 16 GB sticks in slots A2 and B2.

 

[The_Ginja_Ninja]

Thanks for the detailed answer. If it were to work, what is 'better' (I know - a bit vague!):
48GB at lower speed or 32GB at higher speed?

 

[DMAN999]

Thanks for the detailed answer. If it were to work, what is 'better' (I know - a bit vague!):
48GB at lower speed or 32GB at higher speed?

That depends on if you actually use applications that can use 48 GBs of RAM.
For most people 16 GBs is more than enough RAM.
But if you do 3D Modeling or similar work that requires a LOT of RAM then 48 GBs of slower RAM would be better.
But if you just game and use applications that don't require a Lot of RAM then 32 Gbs of faster RAM is better, especially on a Ryzen system.