Highlights and insights from the Microprocessor Forum

AT THE MICROPROCESSOR FORUM in San Jose, The INQUIRER attended some interesting presentations, by proxy. Here are some of the highlights.

PowerPC
IBM has presented the new PowerPC. It's a watered-down, only-one-core version of the Power4. It adds the Altivec vector unit and with the reduced die size it becomes affordable and attractive to Apple.

It's not official that Apple is a customer though.

The new 64-bit PowerPC is a 64 bit machine that runs the 32-bit code natively, on the same pipeline as the 64-bit core.

We've been reminded that the PowerPC specification is originally 64-bit, but contemplates a 32-bit version. There have been two previous 64-bit PowerPCs that flopped.

The new PowerPC triples the pipeline length to achieve higher frequencies of 1.4 to 1.8 GHz in the 2nd half of 2003. We'll see at what frequencies Intel and AMD are running by then.

Banias
Banias is built from the ground up by Intel for the mobile segment of the market. It's intended to avoid the time it takes for its top processors to trickle down into the power consumption appropriate for that market segment.

Of course that's an Intel problem. VIA's processors are 'mobile' from the start.

Banias design targets ALL mobile segments. The processor will start its life as laptop processor and trickle its way down into the mini-notebook and then tablet-PC sub-segments.

The team from Israel responsible for the design figured a rule they are using to leave features out of the design. It's the 3x% rule. A feature that adds x per cent of performance is only desirable if it adds less than 3x% of power consumption as well. So, a feature adding 3% performance but 10% power would be dropped.

Using this philosophy they have reduced 1 watt from the cache power consumption but added 1 extra cycle to its access time.

Also, they claim 20% better branch prediction than other Intel processors (ie a 20% less cache miss ratio) I guess that means they go from a 95% hit rate to 96% or something like that?

For more snippets on Banias, wibble on over to Ace's Hardware Forum here.

Opteron
AMD's Opteron was presented in the server processor section.

There was a question asked about the non-mentioning of reliability during the presentation. It turns out Opteron implements ECC data protection mostly everywhere but it doesn't yet implement parity for internal registers.

Thus Opteron is not good enough yet for mission-critical servers but it's headed there.

AMD also aims to move the core of the server market from 2-way (ie 2-processor) servers to 4-way.

AMDZone has posted a zipped up PDF of the Opteron presentation given at the MPF which you can download from here.

VIA C3
Glenn Henry protested that the Walmart US$199 PC is known as the Lindows Walmart PC instead of the Centaur Walmart PC.

It sports an 800MHz C3, while the Lindows 133MHz Celeron is $499, also from Walmart.

He keeps stressing cheap and low power. Simplicity and reuse of infrastructure (Socket 370) keeps him there.

Glenn claims the C3 to be 'almost a Celeron'. He showed some benchmarks but he didn't compare it against Duron.

Another interesting bit is that the next generation VIA-Centaur processor is going to be an out-of-order execution but it's only in the paper-design stage as of now.

Another curiosity that I didn't know about is the AIS (Alternate Instruction Set) which is a way to directly access the C3 micro-operations. It could be interesting for the 40% of C3s used on non-PC products. µ

The writer is a friend of The INQUIRER.