8GB dual channel vs 12GB single channel

Question

So I was thinking on improving my currently 4GB of RAM and wondering if I should get another 4GB and use them in double channel or stay with single channel and get 8GB extra.

Considering that I usually have lots of programs running at the same time, would the benefits of 2*4GB dual channel apply in any way or will I take more advantage of the 12GB single channel? Would I even need those 4GB extra in the 12GB option anyway?

Solution

As always, the answer will be: it varies. A few main points to consider:

• If you only have single channel memory, then you won't be losing anything by upgrading and staying with single channel
• Dual-channel memory makes a big difference in speed if you are using your CPU's integrated graphics (IGP) for 3D gaming, but aside from that, differences are minimal outside of a few, specialised applications.
• Having too little memory will make things a lot worse than having more, slower memory

Whether you'll need the extra 4GB really depends on what you are doing, and you've not provided enough information to really say. If your programs regularly add up to more than 6GB of memory in total then I would say it will be of benefit - any unused memory is used as cache to speed up other things.

Your decision would ideally be based on running everything you usually do and then looking at the peak commit value in your OS to determine how much memory is used. But in practice, given the small difference in price, just go for the 12GB. There's really no harm, and ultimately, modern processors can use 8 out of 12GB in dual-channel mode anyway, meaning going for 12 is win-win.

[Edit]

Easiest way to view current commit size in Windows 7 is task manager. Technically peak commit would be a better figure but it's harder to get hold of.

Simply put, commit size is just the total amount of memory that has been allocated. Not all of it may be in use but all of it must be set aside in case it is required; if all programs were to use all the memory they've requested at the same time, this is how much you would require.

Under Windows 8 and Windows 10 it's much the same:

Comments

[Ramhound]

You won't notice a difference between single channel or dual channel performance wise. The difference wouldn't be measurable unless you were bench-marking, which indicates what performance you might expect, not what performance you will get..

[Larousse]

I have dedicated graphics for gaming. The programs I usually run are not very RAM demanding on their own (I'm not into video editing, 3D design or any of that), but it's common that I have a lot of them running at the same time and sometimes their response can be considerably slow.

[Larousse]

(Damnit, I sent it unintentionally) Where can I check the peak commit value? Also, you said that I could use 8 out of 12 GB in dual-channel, can you explain further? I thought both RAM modules had to be the exact same for dual-channel to work. Maybe you're referring to 3 modules of 4GB? (I only have 2 ram slots).

[qasdfdsaq]

@Larousse: How you check it depends on what OS you are running - you have not said so I can't tell you. Memory does not have to be the same to run in dual channel mode: intel.com/support/motherboards/desktop/sb/CS-011965.htm#flex

[Larousse]

I'm currently running Windows, so I guess it can be seen in the task manager. No idea on how to interpret it though. Didn't know about flex mode, I've read everywhere that both modules had to be identical, but it's nice to know that I have that other option. Knowing this I'm probably going for the 12GB option. Thank you very much for the help!

[qasdfdsaq]

@Larousse: I've edited the answer.

[Digin Dominic]

@qasdfdsaq I have an Asus 731GT device that supports dual channel memory. When I bought it came with 8gb single channel memory. My question is whether it is possible to upgrade it by adding a 16gb double channel memory and will there be any issues? I used crucial.com scanner and it suggested 16gb double channel memory.