True 3D is much tougher than 2.5D

https://semiengineering.com/true-3d-is-much-tougher-than-2-5d/

by PaulHoule • 3 years ago

63 42 3 years ago

semiengineering.com

BlueTemplar• 3 years ago

It's still not "true" 3D because there's still clearly a preferred direction (it looks like lasagna).

Consider the human brain... or maybe not, since AFAIK it's still only a (heavily folded) surface ?

jayd16• 3 years ago

Is a grid not true 2D?

jfoutz• 3 years ago

Not quite. X and Y are floats. Z is ints. You can’t freely transform in all dimensions

dgb23• 3 years ago

Buildings with multiple stories are stacked lasagna, but they have beneficial scaling properties.

PaulHoule• 3 years ago

When I think of the convolutions of the brain I think a little of "3D NAND" products which are built around trenches

https://newsroom.lamresearch.com/Tech-Brief-Memory-Grows-Up-...

My understanding is that the cerebral cortex has several layers of active neurons "grey matter" in a folded but basically 2D structure and there are bunch of axons "white matter" that connect those layers to other parts of the cerebral cortex and also to other structures that are structurally different such as the brainstem, hippocampus, cerebrum, etc. that evolved at a different time.

pengaru• 3 years ago

Consider the human brain... or maybe not, since AFAIK it's still only a (heavily folded) surface ?

The glymphatic system of the brain piggy-backing atop the cardiovascular system further illustrates the packaging challenges though

swayvil5• 3 years ago

Sometimes I think that 3D doesn't actually exist. Just a fudgey gloss linking the way we see with a nice way to model it. A convenient illusion.

It's hard to rationalize because it is fundamentally irrational.

detourdog8• 3 years ago

Would you credit Brunelleschi for this illusion

https://en.wikipedia.org/wiki/Filippo_Brunelleschi

https://en.wikipedia.org/wiki/Perspective_(graphical)

swayvil5• 3 years ago

I'd credit biology, culture... the usual authors of our thinking.

pdpi• 3 years ago

What do you mean, 3D doesn't actually exist?

detourdog8• 3 years ago

That is why I asked about Brunelleschi. Since that is where I think our system of understanding 3-D came from.

swayvil5• 3 years ago

I mean that the world isn't actually composed of a 3d space filled with 3d stuff. That 3d is just a way of thinking about it.

bigodbiel• 3 years ago

holographic principle?

RobotToaster• 3 years ago

The same is true with 3d printing, most is just 2.5d.

cubefox• 3 years ago

Or 3D videogames, most aren't even stereoscopic.

iforgotpassword• 3 years ago

In video games, 2.5D has a different meaning already, it's referring to those not-really-3d ray casters from the 90s like doom and Duke nukem 3D.

js8• 3 years ago

How do you cool "true 3D"? With 2.5D, the cooler goes on top.

dogma11382• 3 years ago

With 3D the cooler still goes on top, 2.5D vs 3D is more about how the signaling and interconnect is structured. When the interconnects are still mainly planar it will be 2.5D when most of the interconnects are throughsilcon it’s called 3D.

Cooling 3D is more challenging because you need to wick the heat through the stack. It’s usually done by embedding additional metal layers for heat wicking but there is also a lot of research these days into micro channels for in-die liquid cooling.

the-smug-one• 3 years ago

Just how tall would these be? Micrometers, it seems like. I guess that the materials themselves are not heat conductive enough to divert the heat evenly throughout the stack?

This sounds sooo crazy to me :), I've just got 0 intuition about this stuff!

bitL• 3 years ago

Water pipe grid throughout the 3D piece?

wmf• 3 years ago

Yeah, there's been some work on silicon microchannel coolers to enable this.

SturgeonsLaw• 3 years ago

Keep your electrons in the fridge when you're not using them, if your electrons are already at room temperature then you're at a heat disadvantage right off the bat

madsbuch2• 3 years ago

It is kind of funny. A couple of times articles on HN about complexity theory with assumed knowledge of terms like P-time or NP-hard. In these instances some commenters complained that they could not easily understand what it meant.

I really had to read closely to understand that this is about chip design.

dtjb• 3 years ago

A quirk of HNs rule, post title must match article title. If nothing else it gets more people to RTA.

layer8• 3 years ago

The article mentions chips, stacking, packaging, memory and yield in the second paragraph, and foundries, dies, silicon, ICs and PCBs in the third (and that’s just 10% into the article), I thought it was obvious pretty quickly.

madsbuch2• 3 years ago

I agree, as I also had not problem understanding that is was about complexity theory when I see the term NP-hard.

True 3D is much tougher than 2.5D

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