Revision as of 22:39, 16 December 2017

Die sizes

Hello Dahaka88, You've recently added a number of die dimensions to a number of microarchitectures such as Zen, Skylake, and Coffee Lake. In an effort to ensure accuracy on WikiChip, I'm wondering where did those dimensions come from? Thanks --David (talk) 19:56, 15 December 2017 (EST)

The die dimensions are estimated through knowing die size (Xmm2) and physical die height and width relative each other, I will give you "Zen-Ryzen" die example;

Ryzen Die Size 213mm2 which is AMD's number, so I assumed it is correct, then I took the picture of die from the wikichip, :https://en.wikichip.org/w/images/thumb/3/3f/amd_zen_octa-core_die_shot.png/950px-amd_zen_octa-core_die_shot.png

and actual die shot after the delid of the Ryzen CPU,

https://farm5.static.flickr.com/4353/35620962953_8a12c79f69_b.jpg

https://www.overclockingmadeinfrance.com/wp-content/uploads/2017/09/RyZen-Die-Shot-3.jpg

and I measured the width and height by pixels, (2nd picture 1024x448 pixels flickr one),

1024/448 = 2,2857~ so wide side is "2,2857a" narrow side is "1a"

so mathematical equal of 213mm2 is 2,2857a X 1a = 213, 213/2,2857 = a x a = 93,188~ so a = 9,6534~ then multiply a with 2,2857 and 1 for getting dimensions

~22,06 x 9,65 = 212.9 the dimensions I got, of course actual dimension require direct measurement, but mathematically this is pretty close "estimated" die size dimension, :also thats why I used "~" symbol to mention that. I hope that helps how I did this estimated die sizes. — Preceding unsigned comment added by Dahaka88 (talk • contribs)

I see alright. Part of the reason I was asking was because AMD refused to give us exact dimensions. The two die areas we have listed I personally confirmed with AMD, so those are correct. BTW a Zen Zeppelin is actually 212.97 mm2 according to my notes from Hot Chips. You might want to make sure the ratio of your dimensions match the ratio of the images (except for some images like the Skylake server dies, I think the aspect ratio of that image is off). --David (talk) 22:38, 16 December 2017 (EST)