X-bit labs

AMD’s Triple-Core Processors – Yield-Improvement Technique, Says Intel.

Category: CPU

by Anton Shilov

[ 10/08/2007 | 11:53 PM ]

The rather unique triple-core microprocessor by Advanced Micro Devices due in early 2008 is nothing else but a way to increase the amount of working processors based on the new micro-architecture and featuring so-called “native” quad-core implementation, claims chief technology officer from Intel Corp.

Recently announced plans to release central processing units (CPUs) with three cores for desktops inspired quite some interest among end-users, as there is certain trend towards multi-core chips, but right now a lot of software relates on single-thread performance and modern quad-core processors may not be really fast there. However, Intel Corp. believes it hardly makes sense to release tri-core microprocessors and the only reason why its smaller rival AMD does it is necessity to increase production yields.

“I wouldn’t make that much of it. This is a yield-improvement technique, plain and simple. IBM and Sony with their Cell processor – they have eight (processors) on that that chip, and they said, ‘well, seven is the actually the number and one is a spare, or one is dead’. I’m never quite sure whether there’s a dead one or not. It’s just like memory chips today… There are thousands of spare memory bits that are there to ensure sufficient yield,” said Intel’s chief technology officer, Justin Rattner, in an interview with Wired web-site.

The new quad-core AMD Opteron and the forthcoming quad-core AMD Phenom processors use monolith implementation, which means that all the cores are incorporated into a single piece of silicon. By contrast, current quad-core processors from Intel use multi-chip-package technique and incorporate two dual-core processors onto a single piece of substrate. Given that it is considerably easier to manufacture two relatively low-power monolithic dual-core dice than to produce one monolithic quad-core product, Intel’s approach does seem to make more sense from economic point of view, due to the fact that potentially AMD’s quad-core chips have considerably lower yields compared to Intel’s. Still, AMD claims that its quad-core CPUs can deliver better performance.

“So, yes, AMD has a four-core product. I’m sure when they looked at their yield losses, they said, ‘Wow, we can offer a three-core version of this if one of those cores are dead or slow or whatever it turns out to be’,” said Mr. Rattner.

But despite of being rather skeptic towards chips with three processing engines, Mr. Rattner indirectly admitted that such microprocessors will be better than dual-core offerings in applications that take advantage of multi-core CPUs. Nevertheless, quad-core will be even more preferrable.

“In terms of software, there’s software for one core and then there’s software for multiple cores. It’s not like, oh, we have a three-core problem but not a four-core problem,” Mr. Rattner concluded.