4 to 8 GB RAM upgrade compatibility ?

Hi I'd like to add 4 gb ram for total of 8gb ram but still unsure with which one to go. My current ram info below



And the option for additional 4 GB module :

Corsair SO-DIMM DDR3 4GB PC12800 - CMSO4GX3M1A1600C11 (1X4GB)

Corsair SO-DIMM DDR3 4GB PC12800 - CMSX4GX3M1A1600C9 (1X4GB)

Question :
1. Is it compatible for both option ?
2. Is it going to run dual-channel with this different brand/type ?
3. What will i miss if it does not run dual channel ?

Thank you.

 

Yes, it's compatible.
It'll only run dual-channel with a second RAM module (also running at the same speed, or Intel will take the lowest common denominator with Sandy Bridge or newer).
You'll miss a pretty good bit of your RAM bandwidth.

So, if you run either stick that you linked, with the stick of 4GB that's in your notebook, you'll be running on dual-channel at 12800.

 

Thanks H.A.L, that helps a lot, one more question though..

Since my current ram runs at 800 mhz (1600mhz) at 11-11-11-28 and the second option (vengeance) has tested speed and latency of 1600mhz/9-9-9-24, the vengeance is gonna adjust itself to run at the same configuration as my current ram i.e 1600 mhz at 11-11-11-28, isn't it ?.

That's what i grasp from your explanation, am i right?

 

We need to know what laptop make and model your talking about to know what ram specs would work???

 

@Storm

N56VZ, i5 3210m, GT 650m, 4GB ram (current ram info is attached in 1st post)

Thx

 

The Vengence won't adjust itself. The UEFI of the notebook you have will change the RAM timing and speed to whatever is your slowest stick of RAM. So if you have an 800Mhz stick of 4GB, and another 4GB stick at 1600, the UEFI will set the timing and speed at whatever the lowest common speed/timing is... to run in dual-channel mode.

No we don't, since Sandy Bridge. Sandy Bridge and anything newer is able to run in dual-channel in different speeds (asynchronous). It takes whatever is your slowest RAM module and matches the timing and the speed. If you only have one stick, it's single channel only.

EDIT: As an aside, you can also run different amounts of RAM in dual-channel mode, as of Sandy Bridge. So you can have a 2GB 1600Mhz RAM module and a 4GB 800Mhz RAM module. The Intel chipset will run both sticks at 800MHz in dual-channel.

 

Cheers H.A.L thank you.:thumbsup:

 

No problem.

 

@HAL I'm sure you meant it this way but 800Mhz is DDR3 1600 (double-data rate). So OP your RAM will run at 800Mhz but your timings will drop to the most compatible.

 

Yea, wine will to that do you.

You're right though... that's what I meant.

Also, up there where I said Sandy Bridge can run dual-channel in different speeds, I meant capacities. They all have to be running at the same speed.

 

I wonder what rum would do.

 

Both the corsair series are out of stock.. just stop by a small pc shop.. found this cheap $25 4GB ram visipro 12800CL11.. it just works and has hynix chip (?) on it too just as stock n56vz. :thumbsup: