But i really dont understand why they will not be able to make a 6 Core SKU, why they will not be able to disable 2 Cores from the CCX ??
Whether there is a limitation here or not I do not know, maybe others can chime in and help. However, the same prediction still applies to 6C/12T instead of 8C/8T, with a small throughput difference (and a price tad lower to match). It does appear to me though that as long as yields permit, 8C/8T makes more sense financially than 6C/12T while being close enough performance wise to not warrant doing both.
Each unit has 4 cores that share an L3 cache. I'd assume having 2 cores sharing an L3 while the other 4 shared an equivalent L3 would mess things up.
You can disable two cores and half the cache, i dont see any problem with that.
4 Cores active in one unit with entire L3 cache + two cores active with half the L3 cache in the next unit.
But that would still change performance since the L3 is shared. So one core could still obtain more data from the L3 fom the 4 core cluster as opposed from the 2 core with half of the L3 gone.
It seems that each core comes with an L3 slice of 2MB at same clock... Like INTEL, but with bi-star topology, instead of ring topology. Probabily disabling a core, disables only the L3 slice attached to it...Each unit has 4 cores that share an L3 cache. I'd assume having 2 cores sharing an L3 while the other 4 shared an equivalent L3 would mess things up.
Not happening, what you saying doesnt make financial sense. There is no way AMD will loose 4 Cores 8 Threads if there is a defect in just one of the Cores per CCX. Even on Bulldozer (CMT) we could disable one core inside each Module. Im pretty certain they can desable 2 Cores if needed per CCX to create a 6C 12T SKU.
Also, what if you have a defect in 1 core per each CCX ??? you loose the entire die ??? not happening, they will be able to disable Cores within each CCX.
If they already have that many defective units to make SKU's based on them that long before launch then they have big big huge gigantic problems.
Sure some months after release it would make sense if they gathered enough defective dies but not pre release.
As I said before,they might do this at some time but if one of the release skus is 6core they have huge yield problems.
Yeah,or you could just put the chipset and the bios on the die and do your segmentation by limiting clocks,much less wastefull,much more profit.No that doesnt mean they have yield problems, they sacrifice 2 Cores to create a 6C 12T SKU because they actually dont have a 6C 12T die.
Its called segmentation, you have one die to feel 2-3 segments.
Yeah,or you could just put the chipset and the bios on the die and do your segmentation by limiting clocks,much less wastefull,much more profit.
The 8c/16t zen is not supposed to be a desktop CPU.You will again have to sell a 180-200mm2 die for $200 and also, nobody will buy a 8C 16T with 2GHz clocks for desktop.
The 8c/16t zen is not supposed to be a desktop CPU.
No that doesnt mean they have yield problems, they sacrifice 2 Cores to create a 6C 12T SKU because they actually dont have a 6C 12T die.
Its called segmentation, you have one die to feel 2-3 segments. Some dies may be with defects, but you also have to disable cores from good dies as well in order to fill the market.
You save time and resources from creating 2-3 different dies by creating a single 8C 16T die and then you start to disable cores to create different SKUs.
No.. that's.. not correct at all.The 8c/16t zen is not supposed to be a desktop CPU.
No.. that's.. not correct at all.
Yeah,or you could just put the chipset and the bios on the die and do your segmentation by limiting clocks,much less wastefull,much more profit.
He must have misspoke, I mean AMD has said all along they intend the first Zen parts to be 8C/16T HEDT... Emphasis on DT.
Look at intel's HEDT offerings,all much lower clocked then "normal" desktop parts...He must have misspoke, I mean AMD has said all along they intend the first Zen parts to be 8C/16T HEDT... Emphasis on DT.
Look at intel's HEDT offerings,all much lower clocked then "normal" desktop parts...
http://www.intel.com/content/www/us/en/processors/core/core-i7ee-processor.html
Why?Because people buy those for semi professional workloads where the amount of cores is way more important then their speed.
AMD has done similar things before - disabling cores but leaving all of the L3 cache intact.
I wonder how many different Zen dies they are manufacturing? I mean, is there a 4 core die and an 8 core die? Or are they just going to disable cores and L3 cache to make 4 core chips to sell?
I also wonder what the lowest SKU will be? I don't think there will be any dual core Zen SKUs. But then the whole SR3, SR5 and SR7 naming scheme makes little sense, since none of those numbers corresponds to core or thread count. I suppose they want names that consumers can easily compare to the Intel equivalent?
My guess is that the SR3 - or the lowest SKU, whatever that is - will be a 4C 4T part. Possibly no L3 cache.