ram speed and channels

[Toxicfunk314]

Question.....I intend to buy the RAM at the link below because it's a deal.  My motherboard only supports one stick of 1866mhz memory per channel. Question is: Do I run these at 1866 in separate channels or at 1600 in the same channel? Your thoughts please...

http://www.newegg.com/Product/Product.aspx?Item=N82E16820231611

[Epic_Nex]

Is it the same motherboard in your signature?? and im not sure what you saying... are you saying your motherboard can only run memory as high as 1866mhz?

[Epic_Nex]

If it is the mobo in your signature, it has 4 slots for ram and each slot can run as high as 2000mhz, so you should have no problems using those ram sticks

[Toxicfunk314]

If it is the mobo in your signature, it has 4 slots for ram and each slot can run as high as 2000mhz, so you should have no problems using those ram sticks

I got caught up double checking things and doubting myself when I remembered this statement: Note: Only one DIMM per channel is supported for DDR3-1866MHz and higher speed as using an AM3+ CPU. from the supported memory pdf. Lol. If I wanted 4 sticks I would have to run them at 1600MHz. 

[-rascal-]

Thats not what the "Note" says.

Diretly from the Gigabyte GA-990FXA-UD3 motherboard manual:

"Note: To support DDR3 1866 MHz (and above) memory, you must install an AM3+ CPU first."

I'm running a dual-channel DDR3 2133MHz kit in my system...

[Toxicfunk314]

Diretly from the Gigabyte GA-990FXA-UD3 motherboard manual:

"Note: To support DDR3 1866 MHz (and above) memory, you must install an AM3+ CPU first."

I'm running a dual-channel DDR3 2133MHz kit in my system...

That is what the note says. That's a direct copy and paste. I think it very clearly says that when using an am3+ cpu only one stick of 1866 or higher speed memory is supported per channel.  Meaning, yes you can run 2133MHz in a dual channel configuration but only while using two sticks.  

[-rascal-]

That is what the note says. That's a direct copy and paste. I think it very clearly says that when using an am3+ cpu only one stick of 1866 or higher speed memory is supported per channel. Meaning, yes you can run 2133MHz in a dual channel configuration but only while using two sticks.

Wait which version of the manual was your quote from? Mine was from the 2013 English version.

They are simply referring that 1866MHz (and faster) memory is supported on AM3+ CPUs.

You can fit a socket AM3 on a AM3+ board, but the memory controller on the AM3 processors only officially supported up to DDR3 1333MHz.

[Toxicfunk314]

You can fit a socket AM3 on a AM3+ board, but the memory controller on the AM3 processors only officially supported up to DDR3 1333MHz

 

My quote doesn't come from the manual. It comes from the Memory support list. Try your sticks in a single channel and tell me what happens.

http://download.gigabyte.us/FileList/Memory/memory_ga-990fxa-ud3.pdf

[-rascal-]

My quote doesn't come from the manual. It comes from the Memory support list. Try your sticks in a single channel and tell me what happens.

http://download.gigabyte.us/FileList/Memory/memory_ga-990fxa-ud3.pdf

 

Hmm...interesting.

 

Maybe the GA-990FXA-UD3's RAM slots have designed so they need to run at separate channels to achieve 1866MHz or higher.

I'm using a different motherboard (ASUS Crosshair V Formula), and my RAM modules are installed in the same colour-coded DIMM slots -- maybe it varies from manufacturers.

 

This is interesting, I may have to do some testing later this week.

 

 

Regardless, try it in the same channel. If it doesn't work, install them into separate channels. It won't be difficult to move a RAM stick over one slot anyways.

If you can run the RAM at the higher frequency, certainly go for it. If it doesn't work out, 1600MHz isn't going to be a very big loss versus 1866MHz.

 

 

There have been reports of RAM frequencies of DDR3 1866MHz (or was it 2133MHz?) and above not working on AM3+ motherboards...but that is with 4 RAM sticks (all four slots occupied). You're only using two, so you shouldn't run into that that problem.

[Toxicfunk314]

There have been reports of RAM frequencies of DDR3 1866MHz (or was it 2133MHz?) and above not working on AM3+ motherboards

 

That memory support list I linked show's this to be true. Higher speed RAM is supported as long as it is under-clocked to 2000MHz.  

When I wrote the initial post I was just about to purchase the RAM linked when I started doubting myself. In doing that, I remembered reading that memory support list, and because at that time I was considering getting a 4x4gb set of ram, my memory of the post in question was flagged as an issue.  So I over-thought the situation and posted this question, without rereading the original material, and had myself confused about what I was associating the word 'channel' with. 

I realized my quandary was unwarranted shortly after posting this. The RAM in question is currently in my system, looking sexy, cheap, fast, and running at stock 1866 speed. Once you know, you Newegg!