Memory Upgrade Question

[faulkner132]

I currently have an AMD 2600+ with a single 512 MB DDR3200 stick (PNY) running on a BioStar M7NCG 400:
http://www.biostar.com.tw/products/m...me=M7NCG%20400

I noticed in the motherboard specs, the RAM can perform at dual channel, however the motherboard has 3 DIMM slots (Slots 1 + 2 dual channel). First of all, I didn't know the 2600+ was capable of taking advantage of dual channel RAM, so my question is this:
When it comes time for a memory upgrade, which would be better:
1) Getting a 2x512 set of memory and then using my existing 512 for a total of 1.5 GB (I'm wondering if I will lose dual channel by plugging in the third stick)
http://www.newegg.com/product/produc...82E16820145440
- or -
2) Getting a 2x1 GB set of memory and not using the existing 512 (2 GB total)
http://www.newegg.com/product/produc...82E16820145579

Just a few notes on my configuration:
- The CPU power is more than enough, I have no plans to upgrade it (for several years probably) or overclock it, so I want to get any performance boost from my RAM
- I use onboard video (I'm not a gamer) and have my resolution pumped up pretty high, so I would like to allocate 128 MB to it (overkill, but better to have too much in my opinion)
- I make extentive use of the Linux desktop switchers, so I have up to 15 applications open at any one time (not to mention the background services I have running)... it really stresses my current 512

I appreciate any input or insight you hardware experts out there can provide.

[Drunner611]

Yes, unfortunately you will lose dual channel with the 3rd stick. 2gb of ram might be overkill for that system, but for that price, go for it if you want it. Make sure if you only add 512mb more ram that it is the same manufacturer and model that you already have. This would be avoided by getting 2 new 512mb sticks alltogether as you mentioned.

[faulkner132]

So the AMD Athlon XP 2600+ definitely does support dual channel?

I can't find anywhere that is says it does (or doesn't for that matter)...

[Panama Red]

It's not the cpu that supports DC. It's the mobo/chipset that detemines DC support. I have an Asus A7N8X-E Deluxe mobo that has 3 slots and supports Dual Channel. Both yours and mine have the nForce2 chipsets. That's the key to DC support on those socket A mobo's. Doesn't make any difference which cpu we choose as long as it's compatible with the supported bus speeds. I happen to be using an 3000+ 400fsb cpu in mine.

My mobo manual has a chart that shows how the memory modules need to be installed in order to enable DC. I can use A1 & B1, A2 & B1 or all three. B1 on my mobo is the one that sits by itself. The other two are right next to each other. Double check your manual to see what configuratuion is required to enable DC on your board. You can use CPU-z to quickly determine if DC is enabled. The memory tab will say Dual Channel.

edit: Check page 5 of your manual. As long as the 3 sticks "play" with each other, you should be golden!

[faulkner132]

I see, thanks for the good explaination.

I'll probably just go with the 2x1 GB and not use my existing 512 MB (just keep it to test other machines). This way I am assured to get dual channel and 2 GB will be enough to where I should not have to worry about a memory upgrade again for the life of the hardware.