Originally posted by: OMG1Penguin
Isn't dual channel horridly overrated?
Yeah... pretty much with Athlon XP's. The bus that connects the memory controller (north bridge) to the memory is two 64-bit wide buses, hence the name dual, which is basically a 128-bit wide bus. But the problem is the bus that connects the CPU to the memory controller is only 64-bits wide. So the dual memory channels are pretty much choked by the FSB.
Pentium 4's also have a 64-bit data bus between the CPU and Northbridge, the difference is the Pentium 4's bus is quad pumped vs. AMD's double pumped. So you have a 400 MHz effective 128-bit link between the memory controller and the memory, and an 800 MHz effective 64-bit link between the CPU and memory controller. With the Athlon-64, you have a 400 MHz effective 128-bit link between the memory controller and memory, but only a 400 MHz effective 64-bit link between the CPU and memory controller.
There's also some differences in the way the nForce2 chipset handles the two memory channels that don't make it a "true" dual channel design when compared to Intel's I believe. But basically with Athlon XP's dual channel gets you about a 5-10% at best increase in memory bandwidth.
Where dual channel REALLY makes a difference is with integrated video since the GPU has no "onboard" RAM like a standalone video card does. So it uses system RAM. Since the CPU can only ever hope to saturate half of the 128-bit 400 MHz bus, the integrated GPU can use the other half of the whole 128-bit 400 Mhz bus which is part of the reason why the nForce2's IGP is the absolute best integrated graphics solution ever.