dpg said:
This is correct too. But if you are lucky, you will be able to overclock the slower RAM.
Here are two example from my previous PC (motherboard).
1. When I have all 4 DDR slots full, all RAM would workat DDR266 even when all are DDR400
2. If I have up to 3 slots full, I will be limited by the slowest RAM I have. In my case, it was a 256MB DDR333 with two 512MB DDR400. All will run at DDR333.
3. But my DDR333 could work at DDR400 speeds with the same latencies as the DDR400. So when I set the speeds and latencies manually (you have to experiment with this and stress test for few hours using Memtest86+), I could ran all of them DDR400 speeds.
4. But when I installed the other 256MB which was a DDR266, but this also could run at DDR400 speed, I couldn't overclock it even to 270MHz.
It could be any of these two reasons.