Noob memory question

ennogs · 29 Sep 2009 at 00:49

Is there any performance difference bewteen say having 2 X 1 GB ram (same models) and just 1 X 2 GB ram?

Big.Wayne · 29 Sep 2009 at 02:48

Yes if the motherboard supports Dual-Channel memory, using just one stick will cut your bandwidth down and your crops will fail!

Kennysevenfold · 29 Sep 2009 at 11:03

5-6% difference.

Big.Wayne · 29 Sep 2009 at 12:04

Maximum Theoretical Peak Bandwidth is increased by 100% when running in dual-channel (128-bit) vs Single Channel (64-bit)

DDR2-800 (64-bit) = 3,200 MB/s

DDR2-800 (128-bit) = 6,400 MB/s

How these Theoretical differences pan out in the real world will vary depending on application and useage . . .

SMAndy · 29 Sep 2009 at 13:00

I ran some bandwidth tests with my old PC2-6400 a while ago. I didn't test it in single channel mode, but in dual channel, with memory at 880MHz, 4-4-4-12-2T, Sisoftware Sandra was giving me a total bandwidth of about 8600MB/s. the maximum theoretical bandwidth from a single stick is 6400MB/s, and you are very unlikely to actually get this.

Always go for dual channel, its the only way to go.

@Kennysevenfold: how did you get just 5-6% for single channel vs dual channel?

Big.Wayne · 29 Sep 2009 at 16:34

SMAndy said:
the maximum theoretical bandwidth from a single stick is 6400MB/s, and you are very unlikely to actually get this.

Don't you mean Dual-Channel? or are you talking about a stick of DDR3-1600

Greebo · 29 Sep 2009 at 16:43

SMAndy said:
@Kennysevenfold: how did you get just 5-6% for single channel vs dual channel?

Depends on how you test it I suppose. In memory bandwidth tests it will be much greater.

In overall system benchmark tests, it will probably only equate to 5-6% overall difference.