Question Ram mixing

Jun 16, 2021
I have 8gb of ram installed in my pc. One adata 4gb 1333mhz and a Zeppelin 4gb 1333mhz.

When i add a Kingston 2gb 1333mhz stick i have it wont boot anymore.

I tried using asus memok it booted up but in bios and windows it still shows 8gb.

All sticks match with each other when installed two by two together.

Is it because sticks are odd number or they dont match or something else?

Motherboard: Asus p8p67 le
Cpu: ci5 3570

Sorry for bad English
Ram is sold in kits for a reason.
A motherboard must manage all the ram using the same specs of voltage, cas and speed.
The internal workings are designed for the capacity of the kit.
Ram from the same vendor and part number can be made up of differing manufacturing components over time.
Some motherboards, can be very sensitive to this.
This is more difficult when more sticks are involved.
You can sometimes compensate for errors by increasing the ram voltage in the motherboard bios.

If you have your old 4gb mounted in different channel slots, you will get dual channel operation.
When you add the odd 2gb, and you get it to work you will have 12gb and the odd 2gb will run in single channel mode.
That is ok, the extra ram is good.
That is called flex mode.


Feb 20, 2020
I would suggest to buy 2x8 Gb sticks ( may be even 1600 Mhz). It will be faster and you avoid any difficulties.

3 years ago I did the same for my son's PC. He had 2x4 GB RAM and I bought 2x8 GB, because 8 GB was not enough any more for gaming. It was DDR3-ram, too.