Intel switched to fast memory devices for its upcoming Nehalem processors by integrating a memory controller to get over the front side bus constrain faced by DDR3 today and to provide all the bandwidth advantages for its users. The performance memory should be caught up by the memory controller bandwidth providing a high level of RAM performance once the new processors are here.
Although Intel platforms lack the high clock speed advantages offered by the latest memory modules (going up to 2000MHz these days), the performance memory industry is struggling to go for the big prize. The memory bandwidth faces a big problem when it comes to front side bus (FSB), for the simple reason that it limits the bandwidth, mainly as it follows: 8.53 GB/s for the 1066MHz FSB (266 MHz QDR) memory, 10.66 GB/s for the 1333 MHz (333 MHz QDR) modules and 12.8 GB/s for the enthusiastic 1600 GHz (400 MHz QDR) models.
The dual-channel memory managed to overcome the bandwidth limitations of the FSB, going up to12.8 GB/s for the DDR2-800 and up to 32 GB/s bandwidth for the DDR3-2000 model. Still, the ultra-expensive DDR3-2000 models need to be given a hand by overcloking the FSB, otherwise there will not be such a dramatic increase in performance as expected. Also, to reach a 32 GB/s bandwidth, users need to have a processor capable of supporting a 4GHz FSB (1000 QDR).
Intel seems to have managed to eliminate those "FSB brakes" by designing Nehalem's architecture to use 64-bit memory controllers which are connected directly with the processor's silicon. This new design should bring a bandwidth utilization of as much as 90%, a nice jump from today's 50-60% utilization.
According to some sources, the mainstream Nehalem CPU, also known by the name of Lynnfield, Will have the capacity of providing almost the double of the current bandwidth, namely about 18.5-20.1 GB/s for the DDR3-1333 modules.
Perhaps now is the right moment to purchase some DDR3 modules, if you haven't done it already, and wait for the Nehalem processors to come. Two of these are being now prepared by Intel. The Bloomfield aims for the new Core Extreme title and will come with a triple-DDR3 controller. That means that users will be able to go to 30 GB/s bandwidth when using three or six DDR3-1333 modules. Lynnfield, on the other hand, will offer only a simple dual-channel DDR3-1333 controller when it will arrive in Q1 2009.