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Mixing Memory

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bardos

Member
Joined
Sep 2, 2002
Location
Haiku, Maui
I've got a laptop which uses pc2-5300 667mhz DDR II memory. Fine and dandy. There is 1gb of 667mhz memory installed at the moment. Could this laptop also use 800mhz DDR II memory? I know it could use it and still run at 667mhz, but I am talking about the combination of the stick of 1gb 667 and the stick of 2gb 800.

thanks
 
No, two sticks of RAM cannot run different speeds at the same time.
 
Wouldn't the machine underclock the faster RAM to match the speed of the slowest stick? I've never personally done that, but I was always under the assumption that this was the way it worked.
 
So in reference to the OP, yes he can use both the 1gb and 2gb stick at the same time, but both will be throttled to 667mhz. I thought that was his initial question?
 
While success have been documented with such a move, it is not recommended in the least.

That said, the OP's question wasn't if he could use them together at the same speed (he knows it will do that), it was at their (different) rated speeds.

I know it could use it and still run at 667mhz, but I am talking about the combination of the stick of 1gb 667 and the stick of 2gb 800.
 
I've got a laptop which uses pc2-5300 667mhz DDR II memory. Fine and dandy. There is 1gb of 667mhz memory installed at the moment. Could this laptop also use 800mhz DDR II memory? I know it could use it and still run at 667mhz, but I am talking about the combination of the stick of 1gb 667 and the stick of 2gb 800.

thanks

With a laptop, I dunno.

With a desktop:

I do it with my Asus Maximus II Gene and it's fine. I bump the VDIMM to 1.90 V first before installing the sticks.

333 Mhz should be OK.

With the FSB at about 350-ish, prepare to raise the FSB termination voltage to 1.3 V on a 65 nm Core 2 Quad.
 
Motherboards usually read settings from memory in the 1st slot and set all other memory like the 1st one. Also it's recommended to use lower capacity modules in the first slots. New motherboards should see memory no matter in which slots you put them but some older boards had problems to recognize lower capacity memory when it wasn't in the first slots.
 
Well, I have discarded that idea...

However... two sticks of 800mhz DDR II *will* work fine together in a laptop rated at 667MHz??
 
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