Question Binning and yields

[Hulk]

I realize that binning is a big secret and we don't know exactly how manufacturers test processors for functionality and clocks vs. voltage.

What I'm wondering is if there is a cutoff point where low performing parts are simply discarded?

For example, let's look at the current Ryzen 5000 stack. Basically this is a question of chiplets I would think?

Each 5950x is going to require two fully functional 8 core chiplets. One chiplet will need at least one core that can reach the advertised 4.9GHz target.

Each 5900x is going to need two chiplets and the Anandtech review indicated it consisted of two six core chiplets.

Each 5800x requires one fully function eight core chiplet with one core that can reach 4.7GHz.

And finally the 5600x requires one chiplet with six functioning cores.

What does AMD do with the chiplets that only have 5 or less functioning cores? It seems as though we should be seeing 10 core parts right? Or are quad core parts available or going to be available?

How about 12 core parts consisting of 8 core chiplets plus 4 core chiplets, or 5+7?

How about the chiplets with seven functioning cores? Sure they can be used in the 5900x and 5600x but wouldn't they be more profitably utilized in a 14 core part?

Or how about taking all of those chiplets with only 3, 4, or 5 working cores and sell them to corporations in bulk for systems not needing a lot of compute?

I'm just curious as to the economics vs technical feasibility of such configurations.

 

[DrMrLordX]

What I'm wondering is if there is a cutoff point where low performing parts are simply discarded?

There could be any number of reasons why a die might be discarded, or rebranded as something silly enough that they may as well be discarding it. See: FX9590 from years ago. The modules were intact, but leakage was so bad that they really couldn't sell them as anything but "enthusiast" CPUs.

What does AMD do with the chiplets that only have 5 or less functioning cores?

That assumes that AMD's most-common defects in N7 wafers cause entire cores to be fully non-functional; furthermore, look at the R5 3300x for some idea of what they might do with those chiplets in the future. TSMC N7 is mature enough that defects of that type may be pretty rare and may take awhile to accumulate.

 

[maddie]

I realize that binning is a big secret and we don't know exactly how manufacturers test processors for functionality and clocks vs. voltage.

What I'm wondering is if there is a cutoff point where low performing parts are simply discarded?

For example, let's look at the current Ryzen 5000 stack. Basically this is a question of chiplets I would think?

Each 5950x is going to require two fully functional 8 core chiplets. One chiplet will need at least one core that can reach the advertised 4.9GHz target.

Each 5900x is going to need two chiplets and the Anandtech review indicated it consisted of two six core chiplets.

Each 5800x requires one fully function eight core chiplet with one core that can reach 4.7GHz.

And finally the 5600x requires one chiplet with six functioning cores.

What does AMD do with the chiplets that only have 5 or less functioning cores? It seems as though we should be seeing 10 core parts right? Or are quad core parts available or going to be available?

How about 12 core parts consisting of 8 core chiplets plus 4 core chiplets, or 5+7?

How about the chiplets with seven functioning cores? Sure they can be used in the 5900x and 5600x but wouldn't they be more profitably utilized in a 14 core part?

Or how about taking all of those chiplets with only 3, 4, or 5 working cores and sell them to corporations in bulk for systems not needing a lot of compute?

I'm just curious as to the economics vs technical feasibility of such configurations.

What is hardly ever discussed here by silicon enthusiasts is what is the cost, marketing included, of maintaining a separate SKU. By all I've seen and read, this is apparently assumed to be a negligible value. Maybe we should rethink this.

 

[Mopetar]

What does AMD do with the chiplets that only have 5 or less functioning cores? It seems as though we should be seeing 10 core parts right? Or are quad core parts available or going to be available?

There will probably be some quad-core parts eventually. Depending on the design AMD uses, a chip that has exactly 5 functioning cores is highly unlikely. TSMC publicized the defect density for their 7nm process last year because it was quite good and worth bragging about publicly, but that information suggests that AMD should be seeing around 95% yields on their chiplets.

Put another way, almost all of their chiplets are capable of being sold as 8C parts because they don't have anything wrong with them. However, not all chiplets will be able to hit the required clock speeds to be used in a 5950X or other high-end part, so they'll artificially disable cores to make chiplets where 6 of the remaining cores can hit the clock speeds to make a 5900X and so on down the line.

If they do have any chiplets that aren't being used in the current lineup, they're being set aside for future products. We'll eventually see some quad-core replacements, but that won't be until the market for anything above that is saturated. Some of those 4-core chiplets might also find their way into EPYC parts since there's strong demand for server CPUs that have smaller numbers of cores that run at higher speeds.

What is hardly ever discussed here by silicon enthusiasts is what is the cost, marketing included, of maintaining a separate SKU. By all I've seen and read, this is apparently assumed to be a negligible value. Maybe we should rethink this.

What makes it more expensive outside of any additional time spent testing in order to figure out which bin something needs to go into? You rarely see much marketing for specific CPUs either since the focus is on the lineup as a whole and typically the halo products.

The underlying hardware is the same so it doesn't matter if you sell 100 model A CPUs or 50 model A 50 model B CPUs since you use the same packaging, etc. for each and still have to ship them somewhere. Maybe it's more expensive if one of them includes a cooler or something, but that's about it.

 

[Hulk]

@Mopetar,

Great information. Thanks for responding. The 95% yields really is the key here.