AMD Updates CPU Launch Schedule - Phenom 9850 Due In a Few Weeks

[Kougar]

Yeah, it would likely be more power efficient I'll grant, but I could toss together some pretty old parts to make them too. And server boards aren't very power efficient, or made for overclocking dual CPUs.

You raise another question though, because isn't the Cell processor in the PS3, most often a 7-core chip, instead of the 8-core chip it's supposed to be, because of defects?

From what I understand, most Cell chips do indeed have a non-functioning core, so I have to wonder how AMD will manage to pump out 12-core processors that are faultless. I am no fab worker, so I'm really not going to guess at that.

Man, the answer is even more complicated than I thought. I quoted IBM's documention directly below. This was my understanding, that one is usually disabled due to the extremely low yields Cell processors had. It was around 15-25% yields during the first year iirc. Apparently however they built in a spare to begin with.

The Cell BE processor is a chip consisting of nine processing elements (note the PS3 has one of them disabled, and one of them reserved for system use, leaving seven processing units at your disposal).

I'm sure if AMD retains enough market share until they launch 12-core products, then they will eventually launch a version with a few cores disabled to sell off the mostly good chips. 100% yields is not possible, although Intel has been darn close with some of their better fab facilities.

 

[Rob Williams]

Oh, that's interesting. I thought the Cell was an 8-core chip with one disabled... I didn't know about the spare chip solely for system use. So I guess AMD could do the same thing. Produce a 13-core processor and up the yields, and disable one core if it happens to come out perfect, haha.

Good find.

 

[madmat]

Yeah, it would likely be more power efficient I'll grant, but I could toss together some pretty old parts to make them too. And server boards aren't very power efficient, or made for overclocking dual CPUs.



Man, the answer is even more complicated than I thought. I quoted IBM's documention directly below. This was my understanding, that one is usually disabled due to the extremely low yields Cell processors had. It was around 15-25% yields during the first year iirc. Apparently however they built in a spare to begin with.



I'm sure if AMD retains enough market share until they launch 12-core products, then they will eventually launch a version with a few cores disabled to sell off the mostly good chips. 100% yields is not possible, although Intel has been darn close with some of their better fab facilities.

The quad core Phenoms are 100% yield chips since the Phenoms are a pure quad core design versus Intel with their dual dualcore approach, although they've taken to selling the failed quads as triple cores.

 

[Merlin]

Maybe we can see a little competition between Intel and AMD.
But AMD is going to have to do better.

:techgage::techgage: Merlin :techgage::techgage:

 

[Kougar]

The quad core Phenoms are 100% yield chips since the Phenoms are a pure quad core design versus Intel with their dual dualcore approach, although they've taken to selling the failed quads as triple cores.

Well, I was talking about 100% yields in terms of wafers. Technology is just not there yet. That was why IBM designed the extra core into the Cell chip, to increase yields. If you want to get extremely technical, even if a Intel/AMD Quad CPU "works" when fabbed it doesn't make it a 100% yield, because it likely won't meet the top tier bin target, as far as quality goes.

Rob, I also thought it was an 7 or 8 core chip with one core disabled, was the first I'd ever heard of it being 9 cores. Makes me wonder if they use the same policy for their Cell Blades?

 

[Rob Williams]

Rob, I also thought it was an 7 or 8 core chip with one core disabled, was the first I'd ever heard of it being 9 cores. Makes me wonder if they use the same policy for their Cell Blades?

This is a bit confusing, to say the least. From what I can gather, each Cell CPU contains nine cores, but ten threads. There are eight SPEs, each of which are single-threaded, and then the Power Processor Element, which is unlike the other cores, but is still considered to be one. So, it's nine cores, but ten threads.

http://www.research.ibm.com/cell/images/cell-diephoto.jpg

http://www.research.ibm.com/cell/heterogeneousCMP.html

So I am assuming that the PPE is exclusive for system use, while the eight SPEs are what's used for all of the required calculation.

"The Cell B.E. processor is a multi-core broadband processor based on IBM's Power Architecture. A single chip contains a Power Processing Element (PPE) and eight Synergistic Processing Elements (SPEs). Each SPE has an on-chip local store. The PPE has an on-chip L1/L2 cache. Also on the chip are memory and I/O controllers.

The PPE is a general purpose 64-bit RISC processor with 2-way hardware multithreading. L1 cache for the PPE is 32KB instruction and 32KB data. Each of the eight SPEs is a special purpose RISC processor with 128-bit SIMD (Single Instruction Multiple Data) capability and 256KB local memory."

http://www-03.ibm.com/technology/splash/qs20/pdf/cell_be_systems_whitepaper.pdf

From what I can see, Cell Blades and the PS3 share the identical processor, and both probably use them in a similar manner.