2x4GB or 2x4GB + 4GB

[Oakspirit]

I have 2 four gig sticks of Crucial Ballistix Sport which makes 8 GB. I also have a 4 GB stick of random ram that I pulled out of a desktop. Would it be better for gaming and light productivity to use the 2 four gig sticks or use the 2 four gig sticks plus my 4 gig stick I pulled out of a desktop?

 

[smashjohn]

Ultimately it depends on whether your motherboard supports that configuration. But also, memory kits are spec'd as kits. Introducing another stick might require adjusting your ram settings. You won't know until you test.

 

[compprob237]

[strike]It would knock your system out of dual-channel mode and thus adversely effect your RAM's performance.[/strike] All the sticks would also have their speed changed to match the slowest stick which is probably the 4GB random stick. [strike]Only consider it if you're using a lot of swap file space. "A lot" would be above 5GB of USED swap file space.[/strike]

EDIT: I was mistaken with my information. This is cleared up in my post below.

 

[Vic 40]

It would knock your system out of dual-channel mode

No,most likely will the added 4gb stick run in single channel mode and the other two still in dualchannel.This is called "Flex Mode".

 

[compprob237]

It would knock your system out of dual-channel mode

No,most likely will the added 4gb stick run in single channel mode and the other two still in dualchannel.This is called "Flex Mode".

Ah, you are correct when it comes to new motherboards. I'm mistaken in this case as the last time I considered dual-
and triple-channel was with an old DDR1 system I had. I was unaware of "Flex Mode" being introduced into the newer motherboard chipsets. Here's the quote from the manual that I was using about it:
"5. DIMMs installed into any three sockets will function in single-channel mode."
So, after reading your post I pulled up my old P6T's manual and read:
"You may install varying memory sizes in Channel A, Channel B, and Channel C. The system maps the total size of the lower-sized channel for dual-channel or triple-channel configuration. Any excess memory from the higher-sized channel is then mapped for single-channel operation."
Therefore, my previous post was mistaken. I will strikeout the incorrect information and add an edit note to the post. I am still correct about the speed of all the RAM sticks being set to the value of the slowest present stick, though. Even my newest motherboard suggests installing DIMMs with the same CAS latency.

So, now that I'm aware of Flex Mode I can suggest that Oakspirit go ahead and put that third RAM stick in.

 

[Vic 40]

the last time I considered dual- and triple-channel was with an old DDR1 system I had. I was unaware of "Flex Mode" being introduced into the newer motherboard chipsets.

No worries,i still answer based on old assumptions as well. 😉 You (i as well) really need to keep up with new developments,enough new stuf happened and happening.