Ram slots - mix blue and black slots with different capacity of RAMs.

[curioushardwareuser]

Hi, I have 4 slots on my motherboard, 2x Blue, 2x Black. I have 2x 2gb RAM (4gb total now) and they are both in the Blue slot. So if i put a new 1x4gb in one of the empty Black slots, can I reach 8GB RAM in total? Thanks in advance.

My system info:

My RAM slots:

 

[mjslakeridge]

You can try it. It may work, or it may not work. If it does work, all of the ram will run at the speed (frequency) of the lowest frequency ram stick installed.

 

[ac13044]

yes it should give you 8gb in total as stated above it will run on the lowest freq

 

[aquielisunari]

You can try it. It may work, or it may not work. If it does work, all of the ram will run at the speed (frequency) of the lowest frequency ram stick installed.

Add in one of them will be operating in single channel mode that'll run even slower(half).

 

[mjslakeridge]

Dual channel mode doubles the bandwidth between the cpu and the ram, but that does not mean the performance in single channel mode will be half that of dual channel mode.

See the conclusion at the end of this research study:

http://www.hardwaresecrets.com/does-dual-channel-memory-make-difference-in-gaming-performance/7/

 

[aquielisunari]

Dual channel mode doubles the bandwidth between the cpu and the ram, but that does not mean the performance in single channel mode will be half that of dual channel mode.

See the conclusion at the end of this research study:

http://www.hardwaresecrets.com/does-dual-channel-memory-make-difference-in-gaming-performance/7/

Yep. Speed is cut in half. Performance will vary.

 

[mjslakeridge]

I guess it comes down to what the OP is using the computer for, and whether the current amount of RAM is limiting performance in some way. From the screenshot, it looks like it is a 64 bit OS, so more than 4GB of RAM should be supported.

I would run some benchmarks with the current RAM, then try adding the additional RAM and repeat the benchmarks and compare the results. Or just do some real world tasks with the additional RAM to see if performance is better or worse.

 

[geofelt]

If the ram works, you are good.
More ram will usually trump faster ram.
With some motherboards, you will still get dual channel operation with the original ram across two channels, and the odd capacity will be in single channel mode.

But... and a big but.
Adding ram is not 100% guaranteed to work.
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, particularly AMD can be very sensitive to this.
This is more difficult when more sticks are involved.
That is why ram vendors will NOT support ram that is not bought in one kit.

Best to go to a ram web site like Kingston and access their ram upgrade app.
Enter the make/model of your pc and see if they have a list of supported upgrades.

Otherwise, what is your plan "B" if what you buy does not work??

You may end up having to replace your 2 x 2gb ram with a 2 x 4gb kit.
In fact, I would buy a supported 2 x 4gb upgrade with specs the same as your existing ram.
cpu-z will tell you what you have now.
You will have a guaranteed 8gb. Then try adding your 2 x 2gb.
If it works, good, you have 12gb.
If not, keep the old ram as a spare or sell it.