How to choose right memory?


Oct 10, 2012
I have an asus k73e

It has 1 unit 4gb of memory...

Crucial says i could buy a 8gb kit, 2x4gb

is there any reason i cannot just buy a 4gb kit and add to the one i have?




Nov 17, 2011

Sometimes, tho rarely, different sticks from different manufacturers or dates of manufacturer are incompatible or won't run in dual channel mode. Best way to ensure compatability is to buy ram in kits. It's why they are sold in kits.

With all that said, my Asus K53E has 6gb of ram, a 4 gig and 2 gig stick, from different manufacturers and the system says it's running in dual-channel mode...but who knows?


Aug 4, 2012
Im running RAM from different manufacturer.
Samsung and Kingston.
So far does not have any issue whatsoever.
Just make sure the speed and latency matches the RAM you currently have.
Currently running my RAM in dual channel mode and the windows experience score went up to 7.8


If you use mismatched sizes, then some of the ram(or all, depending on the motherboard) will run in single channel mode.
This will be more important to the performance on amd cpus vs. intel.
But, on balance, more ram is usually better and more than offsets the slightly slower cpu.

Ram is sold in kits for a reason.
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.
That is why ram vendors will not support ram that is not bought in one kit.
Although, I think the problem has lessened with the newer Intel chipsets. Still,
it is safer to get what you need in one kit.

You want documented ram compatibility. If you should ever have a problem, you want supported ram.
Otherwise, you risk a finger pointing battle between the ram and motherboard support sites, claiming "not my problem".
One place to check is your motherboards web site.
Look for the ram QVL list. It lists all of the ram kits that have been tested with that particular motherboard.
Sometimes the QVL list is not updated after the motherboard is released.
For more current info, go to a ram vendor's web site and access their ram selection configurator.
Enter your motherboard, and you will get a list of compatible ram kits.
While today's motherboards are more tolerant of different ram, it makes sense to buy ram that is known to work and is supported.


Apr 25, 2011
You forgot to mention the voltage of the ram needs to match otherwise you will have to overvolt or undervolt one of the two.