Asus P6T SE upgrade 6GB to 12GB

Sojourner

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I have 3 slots currently populated with Corsair PC3-10700H (667 MHz) DDR3 RAM (part # VS2GB1333D3) - is this 1333 designation indicate this is 1333 MHz RAM? It is running at 534.5 MHz per channel or about 1600 MHz across all 3 channels... is this a dual channel vs triple channel nomenclature that is unimportant to the actual memory speed? Speccy reports the individual DIMMs as 667 MHz, but running at 534.5 MHz...

So that's a little confusing.

The manual says:

"Due to Intel spec definition, XMP DIMMS and DDR3-1600 are supported for one DIMM per channel only"

"For system stability, use a more efficient memory cooling system to support a full memory load (6DIMMs) or overclocking condition"

I presume that statement 1 above applies to all DDR3 memory in excess of 1333MHz?

Should my current RAM be running at a higher speed than it is?

If I add an additional 6GB (3x2GB) RAM to the currently open slots (which according to the above will not support 1600MHz or above), will all the RAM run at no more than 1333MHz, even if I put something faster in those open slots?

How important is the QVL list provided by ASUS? My son insists this document is totally irrelevant because it doesn't include several of the 4GB DDR3 modules he found on NewEgg. This seems like backward reasoning to me - while that list MAY be out of date, assuming it must be because you couldn't find some RAM in the list doesn't follow. Maybe that RAM isn't on the list because it actually isn't supported! I'm talking about the "updated" list.

About the cooling - between the possibility of dropping the speed of all the RAM and the admonishment to enhance cooling when fully populating all 6 DIMM slots, I was thinking I would have to go to replacing all 3 sticks currently installed in the primary (orange colored) DIMM slots, with 3x4GB DDR3 RAM. There is no space in the case for additional cooling.

What might the consequences of populating the 3 open DIMM slots be, for cooling, and for the impact on memory speed of both clusters of memory? (A1-B1-C1 primary triple channel cluster and then A2-B2-C2 secondary cluster that presumably does not support RAM speeds over 1333MHz)

I don't have the specs on the RAM he picked out for me (3x4GB individual RAM sticks) but the stuff that Corsair makes that MAY match close enough what I have is :

http://www.newegg.com/Product/ProductList.aspx?Submit=ENE&N=100007611%2050001459%20600006050%20600006061%20600006076&IsNodeId=1&name=6GB%20%283%20x%202GB%29&Order=PRICE&Pagesize=20

only the first 3 match speed/latency/voltage 9-9-9-24, 1.5v, Cas latency = 9

The top one ALMOST matches the part # on my Current Ram (with a "G" added at the end) but the 3rd one (the 3x2GB kit) would be $15 cheaper;

Or would I be better off getting a totally new 3x4GB set of RAM and discard the 6GB I currently have installed, because of heat/speed issues?

Who knew adding a little RAM would be so complicated ...
 
Solution
The higher numbers are the _effective_ transfer rate so are usually double the _actual_ clock rate. A lot of mobo's support DDR3 but actaully run it as DDR2. Apparently this mobo runs it as DDR3 so your effective speed would be 3 times the actual clock rate - I think. RAM has gotten confusing due to the marketing hype. Here's a good explanation:
http://www.hardwaresecrets.com/article/Everything-You-Need-To-Know-About-DDR-DDR2-and-DDR3-Memories/167

http://www.hardwaresecrets.com/article/Everything-You-Need-to-Know-About-the-Dual-Triple-and-Quad-Channel-Memory-Architectures/133

What's in the QVL is what Asus has tested and guarantees So you are correct about your son's logic being backwards. That doesn't mean it won't run. It just means...
The higher numbers are the _effective_ transfer rate so are usually double the _actual_ clock rate. A lot of mobo's support DDR3 but actaully run it as DDR2. Apparently this mobo runs it as DDR3 so your effective speed would be 3 times the actual clock rate - I think. RAM has gotten confusing due to the marketing hype. Here's a good explanation:
http://www.hardwaresecrets.com/article/Everything-You-Need-To-Know-About-DDR-DDR2-and-DDR3-Memories/167

http://www.hardwaresecrets.com/article/Everything-You-Need-to-Know-About-the-Dual-Triple-and-Quad-Channel-Memory-Architectures/133

What's in the QVL is what Asus has tested and guarantees So you are correct about your son's logic being backwards. That doesn't mean it won't run. It just means it's not guaranteed to run. You can try it and if you start getting shutdowns or blue screens you'll need to swap it out for something else.

The heat must be dealt with. Maybe you can install larger fans since you don't have room for another one. If not, you'll probably need a new case that provides more cooling. Check your temperatures before installing the new RAM. Then install it and check the temps again. If you see a substantial difference, you'll need to deal with it one way or another - larger fans in existing case, new case, or 3X4Gb although the latter will put out more heat than the existing RAM but I don't know how much difference there will be. Heat is deadly to more than just the RAM - CPU, GPU, PSU, chipset, etc. - so you don't want to run it hot because of the possibility of permanently damaging other things as well.
 
Solution

Sojourner

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If I have to get a new case or add fans and whatnot it is not worth upgrading this system. By the time I sink all that money into RAM, fans (assuming they would fit which I am 98% certain they would not), an SSD drive, and a new video card, I've passed the point where it makes any sense, money-wise, to continue to work with this system. The hope being, of course, that the addition of a little RAM will solve my current issue with ONE game.

Is there no way to estimate the additional heat load or the probability of introducing a heat problem just by adding a little bit of RAM? Is the heat load likely to be less populating only the 3 currently used bank of memory? Is an additional 6GB of RAM in the second memory bank REALLY going to cause the system to overheat?

What the heck does "use a more efficient memory cooling system" actually mean, as I've never seen cooling suggested JUST for the RAM. Heat diffusers don't count - they don't really do anything anyway.

Since RAM is not returnable, buying and then trying is not an option I prefer to deal with. Surely SOMEONE has added RAM to this card before...