Intel Developer Forum 2014

Page 5 - Seeking answers? Join the AnandTech community: where nearly half-a-million members share solutions and discuss the latest tech.

dealcorn

Senior member
May 28, 2011
247
4
76
"Tablet Innovation: Experiences, Usages, and
Opportunities with Intel’s 2015 Tablet Roadmap" (SF14_TABS002_100f.pdf) touts X86 support for Android SDK apps, NDK apps, and game engines Unity, Marmalde, Epic Unreal and Adobe AIR & Flash. None of this will help apps that are no longer supported or where the code is lost. For everyone else and especially Android gaming applications, does heavy lifting remain to be done? Compiler flags will need to be set to create the correct target. Is code redesign typically required? Will Cherry Trail face a substantively level playing field for Android gaming?
 

witeken

Diamond Member
Dec 25, 2013
3,899
193
106
Wow, this schematic vs layout vs fin count is intense. Fin count is no different from layout count at the end of the day. However the amount that fin/layout count differs from schematic count is higher on a finfet process (assuming iso-performance). Planar transistor can vary its width without counting as a new layout transistor up to a certain point. Finfets, without being able to vary the height of a fin, you can only add more fins.
So, how many fins does one schematic transistor consist of, on average? I think it's quite high since Mark Bohr said transistors are often made with 2 and 3 or 4 fins and William Holt said it's very uncommon to use 1 or even 2 fins, so wouldn't that mean that if Broadwell on average has 2 fins per schematic transistor, that the apples to Apples comparison would be (in this fictional case) 2.6B transistor for Core M vs 2.0B for A8?

Sanity check: then it would be possible to put 2.82B fins ~ planar transistors in the same area as A8, which is 41% more which means A8 has 30% less transistors, which is close to what Intel claimed (35%), but it's less than 35% because Intel is using a lower density process. Thoughts?

According to Holt, now Intel often uses often 1 or 2 fins. I wonder how the layout transistor count changed from Haswell(-Y) to Broadwell(-Y). Is it half as much? I also wonder what this meant for density. How much does it improve density? Mark Bohr said the 14nm process has a 0.51x neutral density scaling, but the real density scaling is 2.2x (0.45x), so is that difference caused by reduction of fins?
 

TuxDave

Lifer
Oct 8, 2002
10,571
3
71
So, how many fins does one schematic transistor consist of, on average?

I would tell you, except I would need to hire you first. :p

Mark Bohr said the 14nm process has a 0.51x neutral density scaling, but the real density scaling is 2.2x (0.45x), so is that difference caused by reduction of fins?

I didn't see this quote but it could be several things. Better current/um could improve density as you don't need as large of a transistor to achieve the drive strength you need. Or is he talk about w/ features vs w/o features.
 

witeken

Diamond Member
Dec 25, 2013
3,899
193
106
I would tell you, except I would need to hire you first. :p
Okay, any less detailed information you care to share?

I didn't see this quote but it could be several things. Better current/um could improve density as you don't need as large of a transistor to achieve the drive strength you need. Or is he talk about w/ features vs w/o features.
If you take the transistor estimate (gate*interconnect) and compare it with 22nm, you get a 0.51x scaling, but if you look in the real world, Core M has a 2.2x higher density than Haswell-Y:

14nmFeatureSize.png

BDW-14nm.png


2.2x scaling: http://intelstudios.edgesuite.net/im/2014/pdf/2014_Intel_IM_Holt.pdf page 21

BTW, fast reply. (although I'd rather have a slower but more informative answer)
 

witeken

Diamond Member
Dec 25, 2013
3,899
193
106
The 2.2x area reduction looks like the final result so you can't isolate it to one variable. The improved transistor drive strength helps, but design methodology and design choices can also lead to that 2.2x reduction.

So the reduction in fins per transistor is negligible, as opposed to what Bohr and Holt have been saying?
 

witeken

Diamond Member
Dec 25, 2013
3,899
193
106
It's definitely not negligible, it's quite significant. I just want to get some credit too. :p
Now that I figured you work for Intel, I should try and ask what you are working on? Also, have you ever heard of something called Icelake?
 

III-V

Senior member
Oct 12, 2014
678
1
41
Now that I figured you work for Intel, I should try and ask what you are working on? Also, have you ever heard of something called Icelake?
If I remember correctly, Dave's a uarch guy.
 
Last edited:

TuxDave

Lifer
Oct 8, 2002
10,571
3
71
Now that I figured you work for Intel, I should try and ask what you are working on? Also, have you ever heard of something called Icelake?

I can do my best to answer academic questions. So if you want to know what's a schematic, what's layout, what's in a CPU, <insert generic engineering question here>, I'll be glad to help out. But I generally abstain from anything specific to my work. Sorry!
 

witeken

Diamond Member
Dec 25, 2013
3,899
193
106
I can do my best to answer academic questions. So if you want to know what's a schematic, what's layout, what's in a CPU, <insert generic engineering question here>, I'll be glad to help out. But I generally abstain from anything specific to my work. Sorry!

I already saw that when I just (re)read a whole bunch of your posts. But I tried.

Then what do you work on if we ignore code names?
 
Last edited: