RAM Compatibilty on Asus M5A78L-M/USB3 Motherboard

Hi,

I am wondering if anyone can help tell me if this ram:

Crucial CT25664BA1339 2GB 240-PIN PC3-10600 DIMM DDR3 Memory Module
Amazon.com: Crucial CT25664BA1339 2GB 240-PIN PC3-10600 DIMM DDR3 Memory Module: Electronics

Is compatible with this motherboard:

Asus M5A78L-M/USB3
Motherboards - M5A78L-M/USB3

I already have 3 sticks of this ram:


And I want to add one more stick of the Crucial RAM I listed above. The problem is that my motherboard website doesn't list any 2 Gigabyte RAM sticks as compatible if you check the most recent list! That doesn't make any sense because I am already using 3 sticks that are 2 GB each!

Any help is greatly appreciated.

fireberd said:

According to the ASUS specs for this motherboard it will accept up to 32GB of RAM. As there are 4 memory slots that means it will accept up to 8GB memory modules (4X8=32).

From the ASUS site:
4 x DIMM, Max. 32GB, DDR3 2000(O.C.)/1866(O.C.)/1800(O.C.)/1600(O.C.)/1333/1066 MHz ECC, Non-ECC, Un-buffered Memory
Dual Channel Memory Architecture

True, but I already know all of that. I was looking for a more informed response. Even though the memory I want to buy meets all these specifications it may not be compatible in a configuration with my current RAM. This is what I need help with.

badger906 said:

1) always buy ram in pairs not singularly. you half you bandwidth by not doing so as they dont run in dual channel.

According to my motherboard manual, different types of RAM have these varying compatibilities:


What you are telling me is that I shouldn't buy a single stick of RAM but should instead buy a new dual configuration and waste one of my old sticks of RAM? I don't have much money and would rather not do that .

If I were to buy just this new single stick of RAM and install it in my fourth motherboard RAM slot, would it work? How would it affect the performance of my current configuration?

badger906 said:

if all of your ram sticks are indentical, all the same models, run on the same timings and are all of the same generation youll be fine.. but as youre asking about configuration then they obviously are mixed and matched.

your motherboard has whats known as dual channel lanes. this effectively doubles your rams bandwidth allowing for faster access and usage.

if you dont fit matching pairs into the correct colour coded slots it will work as single channel, and that speed will be governed by the slowest modual and thus halving the bandwidth, which translates to halving the access/transfer speed.

if all the ram is different speeds and brands again it will not work in dual channel. and currently as you have 3 sticks again its not running at dual channel.

yes your new stick of ram will work, but if they arent all thr same it will work in single channel mode, and if the new stick is even slower than the rest it will make the access speeds even slower than you currently have.

So let me get this straight, my Mobo has 4 RAM slots, 2 pairs for 2 dual channels. I currently have 3 sticks of RAM installed meaning that 2 of the sticks are running in dual configuration and 1 in single configuration?

What I want to know is if I purchase this single stick of RAM I linked, if it will lower or raise the overall performance of my RAM. You keep telling me "if the new stick is even slower than the rest it will make the access speeds even slower", how would I know that this is the case? I know almost nothing about RAM and that is why I posted here with the details of my current RAM as well as the RAM I want to add. Can you help me figure out if my proposed RAM addition is faster or slower than my current RAM?

The new stick will "work" in that it will give you 8 total if it is generally compatible and recognized.

Whether all 4 sticks will be in dual channel mode is another question and not knowable for certain until you try it.

If you are doing some task that can use more than 6 gb of RAM, you are better off with the 4th stick, even if it operates in single channel mode.

If the tasks you are doing aren't using more than 6 gb of RAM, it doesn't matter whether you have the 4th stick.

Do you know how often you fully use the existing 6 GB? If it's rarely, never, or unknown, there isn't much point in buying more, regardless.

ignatzatsonic said:

The new stick will "work" in that it will give you 8 total if it is generally compatible and recognized.

Whether all 4 sticks will be in dual channel mode is another question and not knowable for certain until you try it.

If you are doing some task that can use more than 6 gb of RAM, you are better off with the 4th stick, even if it operates in single channel mode.

If the tasks you are doing aren't using more than 6 gb of RAM, it doesn't matter whether you have the 4th stick.

Do you know how often you fully use the existing 6 GB? If it's rarely, never, or unknown, there isn't much point in buying more, regardless.

I don't very often use more than 6 GB of RAM, its just that I had someone offer to buy me a single stick and this is why I am looking into it. If its the case that I can't know for sure that the mixing sticks will run in Dual or not then I think I will reconsider.

Thanks for the advice.

If it's a gift, why not take it??

Worst case scenario: it runs in single channel, but is still MUCH better than not having it at all for those occasions when you need more than 6 GB.