AMD at CES

[Nunz]

we should know in a month or two how the 3d cache will do

but i'll have it under water so it should be fine

i will need a new block as i'm sure the solid copper bar it got on the threadripper won't work

and may not any of the current am4 waterblocks without new mounting as it maybe a taller chip

The issue with the cache+die changes is that your cooling doesn't matter - the limitation becomes the ability of the IHS to transfer the heat to your cold-plate. That's why the 5000 series will still hit 80c even with a custom loop. The thermal density is high and thermal transfer is the limiting factor.

The stacked cache and shaved die will only make that worse, unless they came up with some new method, but everything I've read says they know that the thermal transfer capabilities will be worse - hence the reduced core speeds.

They've said the chip height is not changing, so all AM4 blocks will work. That's the "Z-Height" that was referred to.

 

[demo]

Barely wins 3 and ties 3.. and the 3 that "tied" were the CPU limited benches. It's just crap marketing slides and don't mean anything, but showing 3 ties isn't exactly what I'd call high faith in your product.

Bit weird. Never seen a marketing slide with so many 'ties'

That said, there will be plenty of games that do benefit from the extra cache and those that don't.

 

[bill dennison]

Bit weird. Never seen a marketing slide with so many 'ties'

That said, there will be plenty of games that do benefit from the extra cache and those that don't.

games will likely need to be coded alittle different for 3d cache or a patch

new games after release maybe better

 

[bill dennison]

I'd hate to clean thermal paste off the new AM5 processors.

would be interesting if they can socket a water block over that tall odd shape IHS

 

[Nunz]

games will likely need to be coded alittle different for 3d cache or a patch

new games after release maybe better

The cache is no different from the cache already existing on the chip - the only thing new is the way they placed the cache. Software doesn't see anything different.

Adding cache is not a 1:1 performance increase. I said it a while ago, that 15% is generous and likely will not be that number in gaming applications. You'll see more boost in workstation loads and synthetic benchmarks, though.

 

[pax]

They were talking about putting in cooling layers in 3d stacked chips. One model was using empty silicon thats used to help dissipate the heat and another fancier model had actual liquid cycling between the layers... I wonder if they skipped it this time for this one off 7nm cpu and achieved their temp goals with the slight clock drops.

All those gaps in the IHS of the am5 model might be for some cooling system...

 

[Nunz]

The more layers mean the worse the thermal transfer. The empty silicon would just make already poor thermal transfer a larger issue - direct-die is king for that very reason. I'm no engineer, but it makes sense to me. You want to be as close to the heat source as possible, and extra layers are pulling you further away from the heat source. I would not want a liquid layer in the silicon itself unless it was part of a connected system that interacted directly with that liquid.

 

[andino]

There was some talk about in die liquid cooling for the last few years that was gaining traction. The chips would have channels in place for a liquid to cool the hottest parts of the CPU in the die and then that liquid would be sent to the IHS for cooling. It cycled from heat alone so there was no need for a mechanical pump in die. Pretty sure that they were contemplating using that tech in the near future.

https://arstechnica.com/science/2020/09/researchers-demonstrate-in-chip-water-cooling/

https://www.extremetech.com/computi...r-cooling-for-future-high-performance-silicon

With AMD going to multiple layers it would be easier for them to put that kind of cooling system in place.