Question Mixing RAM


Aug 16, 2014
I currently have 16Gb (2x 8Gb) DDR3 800MHz [] Corsair Ballistix in my Asrock Z87M Extreme4 mobo.

I wish to go to 32Gb by adding two more 8Gb modules in the spare slots so I can keep my existing ram to save money!

I can't source exact duplicates of my existing RAM so is it OK to mix different speeds and latencies. If that means the new ones running at 800Mhz then so be it but it is the amount of RAM not the speed that will make the most difference to my Lightroom/Photoshop editing. Am I right in this assumption by the way?

Thanks in advance.
See if you can determine how sensitive your apps are to the amount of ram you have.
In photoshop, you can adjust this number.
Try reducing the allocation a bit to see if it makes a difference.
Here is info on maximizing photoshop performance.

You may find that the amount of ram makes little difference in what you do.

On the assumption that you want more than 16gb, there are a couple of ways to go about it.

As you indicated, adding a 2 x 8gb ram kit like the one you have should likely do it.
The problem is that 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.
Intel ram controller is reasonably tolerant of mixed ram.
If you match the make/speed/voltage/cas specs, I might guess your odds of success are perhaps 90%
The question is... what is your plan B if it does not work?
If it should not work, adding ram voltage in the bios sometimes does the job.

The other option is to buy a complete 32gb kit.
You can use up to 2800 speed.
sell the old ram or keep it as a backup.