To dual channel or not dual channel..

[Helvetica Blue]

Evening..

just had a prob with my PC where it wouldn't boot.. or even run through the BIOS.. pinned problem down to a dodgy memory stick (I tested my 1Gb remaining one in all 4 channels and it worked in all of them).. so I decided to replace the memory..

I'm going to get a pair of 1Gb sticks and run them in dual channel mode.. but then I had an idea.. I've still got a perfectly good 1Gb sitting there doing nothing.. which brings me to my question..

I know I can't run dual channel with 3 sticks.. but in real-term performance.. will the advantages of running 3Gb in single channel mode outweigh those of running 2Gb in dual-channel mode? My suspicion is that the single channel 3Gb mode will perform better but was wondering what others think?

[system7]

Dual-channel adds about 5% performance.

Why not just buy a single replacement 1 GB stick of similar memory.

I've never found it to be that critical, so why not hope for the best? :D

There's a complication with the 945 chipsets. For 4 sticks of memory they prefer single sided too.

So Double Sided Corsair Value Select only works up to 2 GB as I understand it. Above that you need TwinX.

[Helvetica Blue]

Yeah I might just buy the single stick but I'm aware that the mobo calls for matched pairs..

[system7]

You can identify what you have with CPU-Z and look for a match:
http://www.cpuid.com/cpuz.php

It's your call. Matched pairs come from the same batch, it's not that they get tested in any particular way. So one batch of Kingston might be made with hynix chips, another might be Infineon or something. You follow? I've mixed all sorts of stuff and still got dual-channel. Just I wouldn't bet my life on it. :)

[Helvetica Blue]

Well I'm going to run 4Gb memory in total after an upgrade.. now I've made a wee error getting the extra sticks.. I'm assuming that running 800Mhz memory in a board which only supports up to 667Mhz will simply result in the memory running at the fastest speed the motherboard will allow?

[system7]

I'm sure DDR2-800 will be fine, since it's usually backward compatible, so you may as well get the newest. But it will clock at 333 MHz (DDR2-667 speed) with an Intel chipset and a FSB 266 processor here, which is what is meant by the word "Supports". Though you may be able to overclock more easily, if that's your bag.