As Intel and AMD prepare for battle once again, we check out the processor offerings for 2008 from both companies.
Nehalem, Intel's code name for its next big leap in CPU technology, is named after a small town near the northwest corner of Oregon. The name originally refers to a north-western tribe of Native Americans known more commonly as the Tillamook.
In keeping with the company's tradition of premiering new CPU microarchitectures in even years, Nehalem will represent a fairly significant enhancement over current Core 2 processor technology. In fact, the buzz around this new processor class has indicated that it will represent the biggest set of changes since Intel released the Pentium Pro in 1995.
We've outlined the most important new features below:
Integrated memory controller - This is perhaps the biggest news and the biggest philosophical/structural change in Nehalem. Intel has confirmed that this processor will mark the demise of the Northbridge memory controller. By integrating the memory controller - the logic chip used to handle the input and output of data moving to and from memory - on to the CPU core, Intel will circumvent the throughput limitations imposed by the front-side bus.
The result will be data transfer rates up to 32Gbit per second. This is an important consideration, given Intel's ambitious multicore plans for this new chip. Intel's name for its new memory controller is the Intel QuickPath Interconnect.
The decision to move to an integrated memory controller has stirred some controversy amongst AMD fans, who have derisively commented that Intel finally understands what AMD did many years ago. Beyond reducing memory access speeds and latencies, the integrated memory controller should also offer reduced power consumption.
DDR3 memory - Another big architectural change is the shift to faster DD3 SDRAM.
Native quad-core, octo-core and beyond - Nehalem is being constructed from the ground up to permit native (meaning all cores on a single die) quad- and octo-core functionality. Given this, it's easy to assume that we'll see dual-die 16-core processors in 2009.
Integrated graphics - In September 2007, Intel announced that Nehalem would also have the capacity for integrated graphics, meaning that 3D graphics processors would be located on the same chip as the CPU. The important distinction between Intel's integrated graphics and AMD's approach is that in Nehalem, the graphics processor will not be integrated at the die level. Instead, it will be on the same piece of silicon, but on a separate die.
Other enhancements in the Nehalem microarchitecture include an improved version of hyperthreading and dramatically improved simultaneous multithreading, which will allow multiple processor cores to pool available cycles and memory to better handle CPU-intensive applications. Improved shared caching at the L2 and L3 levels will further help these processors perform more effectively.
It's important to note that Nehalem does not represent a reduction in die size. This shift will come in 2009 when Intel shrinks the Nehalem architecture to 32nm in the processor family currently code-named Westmere. Assuming Intel stays on its tick-tock routine, in 2010 we'll see another brand new processor microarchitecture, currently code-named Gesher.
In terms of specific CPUs, the first wave of Nehalem desktop chips (currently code-named Bloomfield) will be released in late 2008. Internet speculation has indicated that the quad-core variants of these Nehalem-based Bloomfield processors will likely feature 8MB of shared L3 cache and sport three separate DDR3 memory channels. It's likely that we'll also see octo-core variants of Bloomfield in the fourth quarter of 2008 as well.
On the server side, Intel has two chips in development code-named Beckton and Gainestown. Internet rumours have indicated that Beckton will be a native octo-core CPU (with 16 cores available in a dual-socket configuration), while Gainestown will be more like Bloomfield.
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