AMD Announces Triple-Core Phenom Processors

MojoKid writes "AMD has officially announced their triple-core Phenom multi-core processor offering, suggesting a triple-threat of processors, from dual-cores to triple-cores and native quad-cores coming to market this year. While the term symmetric multi-processing (or SMP) suggests a balanced approach of multiple cores in an even number of engines working together on a single workload, AMD offers that an odd number of processors can slice at that workload just as efficiently. Time will tell how this architecture will scale amongst various multi-threaded applications and real-world usage models. AMD is definitely moving to make use of these quad-cores that don't quite make the cut by testing them fully as triple-cores and realizing some revenue, rather than throwing them away."

Comments

Single, double, triple, and quad

[Bryan Ischo]

Wouldn't it make sense to sell any part that had at least one working core? Meaning that if in making quad-core chips, W% of them ended up only having one working core, X% had 2, Y% had 3, and Z% had four, wouldn't it make the most sense to sell all of these chips?

This implies that they have a way to use all four cores independently. Maybe they can't; maybe one core is "special", like the "master" core that has to be working for anything to work. Also this implies that the cores can detect that their sibling(s) aren't working and switch to a mode in which the sibling is not used at all.

Also, a question - when a core doesn't function properly, is it somehow disabled completely so that it doesn't use any power? Or maybe a core that isn't being fed any instructions doesn't use any power anyway?

Re:Nothing new here.

[n dot l]

Sort of. Each core can run two threads at the same time (but both threads share the same cache, if I'm not mistaken) so it's somewhere between a hyper-threaded triple-core processor and 3 dual-core processors.

Re:I wonder how many GHz these can crank out

[Seumas]

Quite good, perhaps, but for less money you can certainly get better performance out of Intel. As much as I have loved AMD for the last decade, Intel is completely eating their lunch at the moment and Phenom and Barcelona are not going to save them. We can only hope that in the next couple of years, they have something in the pipeline that rescues them and their less than 15% market share, before someone gobbles them up.

Re:Fourth Core Unlocking

[level_headed_midwest]

There are a few possibilities:

1. The core is there and locked off via microcode like the extra quads on a cut-down GPU (e.g. Radeon x1900GT vs. x1900XT) and can be enabled with a microcode flash.
2. The core is there but the fuses that connect it electrically to the rest of the die are blown, so it is there but not able to be enabled.
3. The core was never there as the die only has three cores in it in the first place- you have a fully-functional piece of silicon, so there is nothing extra to enable.

Either way, it's really long odds you'll get a free core enabled. Nobody has been able to even upward-unlock the K8's multiplier and I know for a fact that is set in microcode (some guys on ExtremeSystems got a JTAG and found that out but not how to change it.) They will probably use the same method they used to disable one core on a dual-core die and sell single-core Manchester and Toledo-die chips and AFAIK nobody has unlocked any of those. I bet they have a few of the X3s be X4s with a bad die, but the X4 is a darn big chip at nearly 300 mm^2 and the cost reduction by using a native 3-core die would be mighty attractive to them so I guess that most will be #3 then.