What means "dual channel"

As 64bit platform is getting common I was interested how dual channel is really a dual channel and what are the limitations. My computer vedors does not give me a lot of probablity to run dual channel with OEM memories, but I tried that.

I tried three different DDR modules in various combinations

1. 2x VDATA 512MB RAM DDR400 CL 3.0
2. 2x CANYON 512MB RAM DDR400 CL 2.5
3. 2x PQI 256MB RAM DDR400 CL 3.0

These are results of combinations with Auto detection settings

RAM combinaton                Mode                 Timing    Clk Throughput MB/s
2x PQI                        Dual Channel 128bit  2.5-2-2-5 200 1683
2x PQI + 1x CANYON            Single Channel 64bit 2.5-4-4-7 164 1198
2x PQI + 1x VDATA             Single Channel 64bit 3-4-4-7   ?   1159
2x PQI + 1x VDATA + 1x CANYON Single Channel 64bit 2.5-2-2-5 200  751
2x PQI + 2x CANYON            Dual Channel 128bit  2.5-4-4-7 164 1644

Manual setting

2x PQI + 2x CANYON            Dual Channel 128bit  2.5-4-4-7 200 1861

---

Email comment