Thursday, February 27th 2020

AMD Gives Itself Massive Cost-cutting Headroom with the Chiplet Design

At its 2020 IEEE ISSCC keynote, AMD presented two slides that detail the extent of cost savings yielded by its bold decision to embrace the MCM (multi-chip module) approach to not just its enterprise and HEDT processors, but also its mainstream desktop ones. By confining only those components that tangibly benefit from cutting-edge silicon fabrication processes, namely the CPU cores, while letting other components sit on relatively inexpensive 12 nm, AMD is able to maximize its 7 nm foundry allocation, by making it produce small 8-core CCDs (CPU complex dies), which add up to AMD's target core-counts. With this approach, AMD is able to cram up to 16 cores onto its AM4 desktop socket using two chiplets, and up to 64 cores using eight chiplets on its SP3r3 and sTRX4 sockets.

In the slides below, AMD compares the cost of its current 7 nm + 12 nm MCM approach to a hypothetical monolithic die it would have had to build on 7 nm (including the I/O components). The slides suggest that the cost of a single-chiplet "Matisse" MCM (eg: Ryzen 7 3700X) is about 40% less than that of the double-chiplet "Matisse" (eg: Ryzen 9 3950X). Had AMD opted to build a monolithic 7 nm die that had 8 cores and all the I/O components of the I/O die, such a die would cost roughly 50% more than the current 1x CCD + IOD solution. On the other hand, a monolithic 7 nm die with 16 cores and I/O components would cost 125% more. AMD hence enjoys a massive headroom for cost-cutting. Prices of the flagship 3950X can be close to halved (from its current $749 MSRP), and AMD can turn up the heat on Intel's upcoming Core i9-10900K by significantly lowering price of its 12-core 3900X from its current $499 MSRP. The company will also enjoy more price-cutting headroom for its 6-core Ryzen 5 SKUs than it did with previous-generation Ryzen 5 parts based on monolithic dies.
Source: Guru3D
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89 Comments on AMD Gives Itself Massive Cost-cutting Headroom with the Chiplet Design

#76
ARF
thesmokingman
You are implying all the perf gains AMD had are from chiplets. That's pure conjecture. Chiplets actually reduce performance especially in regards to cache and memory. This is where AMD's design has been steadily improving. Look at the single CCD chips, 3600 to 3800x, they all have half the write speeds of dual complex chips. Duh! From Zen 1 to Zen 4, it has been about improving the way the chiplets access the IO and memory.
The performance gain from 64 cores vs 56 cores. I hope you don't say that Intel's 56 cores are faster.
AMD EPYC™ 7742 @225W vs Intel® Xeon® Platinum 9282 @400W
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#77
gamefoo21
Mats
We already know this is wrong. The 3700X has a larger die size in total than the 8C APU counterpart.

The APU's have less cache at least, so they are in turn a compromise compared to the CPU's.
The 12nm I/O die takes a bunch of space and the APUs also have less cache don't they?

There's your shrink. I wonder if the desktop ones will be exactly the same or be different from the mobile editions.
Posted on Reply
#78
londiste
gamefoo21
There's your shrink. I wonder if the desktop ones will be exactly the same or be different from the mobile editions.
AMD has a policy of having as few different dies as possible. Same dies.
Posted on Reply
#79
ARF
londiste
AMD has a policy of having as few different dies as possible. Same dies.
As few different projects as possible due to lack of finances to support them ;)
Posted on Reply
#80
Makaveli
Raendor
So, does this mean 4000 series will be priced cheaper than current 3000 prices already or they will also discount the 3000 series further down? I was thinking about getting 3600 and moving my trusty 6700k to htpc, but if the prices will get even better, I don’t mind to hold on a bit.
How are you getting 4000 series will be cheaper than previous gen from this article?

When has a new Generation cpu ever been cheaper than previous gen?
Posted on Reply
#81
theoneandonlymrk
londiste
AMD has a policy of having as few different dies as possible. Same dies.
Consider just how many different designs they have put out in the last ten years, that's just in accurate.
Posted on Reply
#82
Mats
gamefoo21
The 12nm I/O die takes a bunch of space and the APUs also have less cache don't they?
You just repeated what you quoted from me? :D

In your previous post you said the APU is larger, I said it's smaller, there's a link to a pic in this thread.

gamefoo21
There's your shrink. I wonder if the desktop ones will be exactly the same or be different from the mobile editions.
A shrink and a compromise. The first two generations of Ryzen APU's have used the same die for both mobile and desktop.
Posted on Reply
#83
gamefoo21
Mats
You just repeated what you quoted from me? :D

In your previous post you said the APU is larger, I said it's smaller, there's a link to a pic in this thread.


A shrink and a compromise. The first two generations of Ryzen APU's have used the same die for both mobile and desktop.
LoL I think we were beating around the same argument.

I should have clarified an all 7nm monolithic Zen 2 CPU design would be smaller than a monolithic Zen 2 APU.

The previous gens were based on Zen and Zen+ that were monolithic to begin with too.

I really hope AMD doesn't kill PCIe 4.0 on the desktop APUs then. One point is that a monolithic die can use less cache to get similar or better performance as you don't need the big caches to offset the latency hit of chiplets.

I'm really curious to see the memory benchmarks of the Zen 2 APUs. Does it have full speed memory read and writes and the latency.
Posted on Reply
#85
gamefoo21
ARF



I like how the Intel gets sloppier timed ram and it's on CR:2 vs the 3950X.

I wants APU not CPU... Heh
Posted on Reply
#86
Mats
I don't expect PCIe 4 on desktop APU's, it makes no sense. Also, I don't expect different dies for desktop and mobile APU's, makes no sense either.
Posted on Reply
#87
Apocalypsee
Mats
I don't expect PCIe 4 on desktop APU's, it makes no sense. Also, I don't expect different dies for desktop and mobile APU's, makes no sense either.
It made sense to some, as there is limited PCIe lanes on APU so by having PCIe 4 it could have more bandwidth with fewer lanes.
Posted on Reply
#88
Mats
Given that the X570 boards needs active cooling, something I haven't seen in mainstream boards for years, it would surprise me if PCIe 4 was used in laptops.
It seems to be using too much power, and can run very hot.

Or does mobile Ryzen 4000 have PCIe 4?
Posted on Reply
#89
InVasMani
Vya Domus
The main advantage isn't even the cost saving, it's the fact that they can build processors that would otherwise be physically impossible to make due to hard limits in the manufacturing process. That's "priceless".
Just the ability to bin and filter the defect impact on the overall chip design is a big thing so I can't agree more. It's a much better setup than a stuck with what you got approach to the entire process when you could split it apart a bit and get better results in the grand scheme much more easily and have a more diverse product portfolio to offer at different price points. The fact is some degree of defects in the process is really a bit of a given and the bigger and more complex the whole product is the more difficult and costly they are to weed out.
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