Up to this point we'd used the Gigabyte P35C-DS3R motherboard exclusively, but now we switched to an Asus P5K3 Deluxe WiFi AP model, which only supports DDR3 and has better control over CPU and memory timings than the Gigabyte.
The first surprise is that using like-for-like settings shows the Asus in a very poor light. With the FSB at 440MHz and the memory set to 1,408MHz with tighter latency timings of 9.0-9-9-25 than the Gigabyte would allow, we saw performance that was five percent slower overall than the Gigabyte. Every part of the system was faster apart from the CPU, which delivered ten percent less performance!
We had hoped that the Asus would enable us to overclock the processor to a faster speed, albeit on standard voltage. However, the CPU maxed out at the same 440MHz/1,760MHz FSB and the memory wouldn't go to the next step after 1,408MHz, which is 1,467MHz, so we used the only option available and pulled the latency timings even lower to 7.0-7-7-20. This improved performance to the extent that it nearly matched the Gigabyte, but not quite.
First, we need to give a big shout out to Intel, for creating its Core 2 processor, which is not only a great performer at stock speeds, but also overclocks like a, ooh, like a really good overclocker.
Now to the bad news - not to be too gloomy about this, but the bottom line is that it can only be advised to steer clear of DDR3 at present, as in terms of performance, which is what it's all about, it's a waste of money.
Even fast DDR2 is, as we have demonstrated clearly, only worthwhile if you are actually overclocking, as it enables you to raise the front-side bus, without your memory causing a bottleneck.
DDR3 will of course come into its own as speeds increase still further, enabling even higher front-side bus speeds to be achieved. For now though, DDR2 does its job, just fine.