I’m pretty sure that the next time I go to a trade show where new silicon is being announced, the next tool I need in my backpack is a set of calipers in order to measure the die size. While die size doesn’t in of itself mean much as a number on its own, it is the end result of lots of hard work, focused co-design between silicon engineers and the semiconductor fabs, and ultimately there’s a fine balance between features, die size, performance, power, and at the end of the day, cost. With AMD showcasing the first x86-based 8-core CPU to move into the 15 W power envelope, finding out the die size is one of the elements of our investigation into how AMD has created its new Renoir / Ryzen Mobile 4000 product.

When I first saw the silicon, I wasn’t able to take pictures. Instead, I had to guess the size by manually placing it next to a 8-core Zen 2 chiplet from AMD’s monster 64-core Threadripper 3990X. We’ve known the die size for a while now, at 10.32 x 7.34 mm, or 75.75 mm2. My guess at the time that the new Renoir APU was almost exactly double the Zen 2 chiplet, and I mean it was scary how close to double the size it was. At the time of the announcement of Ryzen Mobile 4000, I had stated in our article that I estimated 150 mm2 for the die size. Turns out, I wasn’t too far wrong.

This image is not to scale.

Later at CES, I went up to the AMD booth and this time they were more than happy for me to take photographs of the new silicon. The 3990X was also there, so I could place the two side by side and get a reasonable reference photograph on which to do calculations. This is the point of the event where I should have remembered to bring calipers! Taking photographs of chips is actually quite hard, making sure you get them lined up perfectly to get the same perspective, but also having enough light to get clear defined silicon edges.

In our picture, the Renoir chiplet you may notice is very slightly angled to the camera, which we’ve compensated for in our measurements.

With that in mind, here are our numbers.

The Zen 2 chiplet on the left, measures 10.32 mm by 7.34 mm, which is a ratio of 1.406 to 1.
In our image, the chiplet measured 265 pixels by 189 pixels, which is a ratio of 1.402 to 1.

In our image, the Renoir SoC measured 282 pixels by 350 pixels, which is a ratio of 0.806 to 1.
If we take the corresponding pixel dimensions, that gives us 10.98 mm by 13.59 mm, a ratio of 0.808 to 1.

This means that the die size of an eight-core Renoir APU with eight 2nd Gen Vega compute units, according to our calculations, 149.27 mm2.

Die Sizes
AnandTech x y Die Size Process Cores EUs/
AMD Zen 2 Chiplet 10.32 7.34 75.75 mm2 TSMC N7 8 -
Intel Ice Lake 11.44 10.71 122.52 mm2 Intel 10 4 64
Intel Tiger Lake 13.64 10.71 146.10 mm2 Intel 10+ 4 96
AMD Picasso 19.21 10.92 209.78 mm2 GF 12 4 11
AMD Renoir APU 13.59 10.98 149.22 mm2 TSMC N7 8 8

That’s pretty close to my 150 mm2 estimate, and I’ve also spoken to a few trusted individuals who have been tracking Zen 2 die structure sizes and graphics structure sizes, and they came out very similar, within 1mm2 or so.

At 149.27 mm2, assuming that AMD is achieving the same defect ratio on the silicon as reported by TSMC for the standard N7 process (0.09 defects per cm2), the process yield should be around 90%. Obviously that doesn’t take into account manufacturing for yield, or the distribution of the power/frequency of the chips within a wafer, but it’s still rather impressive.

Before AMD announced this new chip, there was a good deal of speculation as to how AMD would build it: either four cores with more graphics, or with eight cores and graphics only a little better. One factor of that was the die size: at 200 mm2, one would have expected AMD to definitely use eight cores. For sub 125 mm2, in order to maintain GPU performance, perhaps a quad-core design only have been suitable. However, AMD is claiming a great win here: eight Zen 2 cores, with frequencies at 1.8-4.3 GHz at 15 W, and despite fewer graphics compute units (down from 11 to 8), a higher per-compute unit performance claim of +56% means that performance is actually higher. All just shy of 150 mm2.

We are living in the future. I can’t wait for more.

It's worth noting that AMD's official number for the Zen 2 die size is 74 mm2. This is derived from the floorplan of the chip, which during manufacturing has additional space added to ensure clean die seperation between adjacent die prints. Ultimately what we get as the consumer is that seperation lane (known as a scribe lane) from one side of the die to the other, which is just slightly bigger than the floor plan that AMD supplies to the fabrication plant / TSMC. With calipers, what we get is that additional space, which is above AMD's quoted size.

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  • Fataliity - Tuesday, January 14, 2020 - link

    Actually 2 cores of Ice Lake is about 25mm, (I think 22mm), 4 cores is about 50mm. So 8 cores would be 100mm. 166.52
  • extide - Tuesday, January 14, 2020 - link

    Actually 4c is 30mm2 https://en.wikichip.org/wiki/intel/microarchitectu...

    So -- that puts it almost exactly at 150mm2 like Renoir.
  • cheshirster - Wednesday, January 15, 2020 - link

    ICL has AVX-512 and a large part of silicon dedicated to TB3.
    I'd say it is densier.
    But don't forget this is 10+ already, not the original 10nm.
  • e36Jeff - Tuesday, January 14, 2020 - link

    You're slipping Ian, you were off by 0.52%. I expected better of you.
  • AlB80 - Tuesday, January 14, 2020 - link

    How many PCIe lanes for gfx does Renoir have? x8 or x16?
  • shing3232 - Tuesday, January 14, 2020 - link

    Also, Renoir cut down L3 by Large margin.
  • Lord of the Bored - Tuesday, January 14, 2020 - link

    "This image is not to scale."
    Well, color me disappointed. Thought we were going back to the days of REAL COMPUTERS that filled up an entire filing cabinet.
  • MDD1963 - Thursday, January 16, 2020 - link

    Would be nice to see a desktop APU (R5-4600G?) equivalent with 6c/12t, and enough GPU power to match a GTX1050 or so at gaming.... (IF folks thought the 2200G/2400G sold well, the above should sell by the proverbial freighter-full!
  • maroon1 - Thursday, January 16, 2020 - link

    Gtx 1050 ? You must be joking
    Current desktop APU barely match GT 1030 GDDR5

    And Renoir is barely better than current APU in the GPU side
  • Korguz - Friday, January 17, 2020 - link

    " And Renoir is barely better than current APU in the GPU side " ahhh so you have bench marks that show this ?? post a link so the rest of us can see then too

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