Nvidia Ampere Discussion [2020-05-14]

I think it’s fair to assume GDDR6X is going to account for a significant chunk of the power budget. It would explain the relatively svelte 220W TGP for the 3070.

I wouldn’t bet on AMD smoking the 3080 In pure raster. Best case Big Navi will come with a 384-bit bus at 16Gbps which puts it at exactly the same bandwidth as the 3080. It should make for a very fun matchup though especially if RDNA2 clocks high.

you think the 320W is for a 20 GB model? Otherwise 3080 is 10 GB and 3070 is 8 GB, which shouldn’t be that much of a difference.
 
3070 is GA104, 3080 is GA102 this time around.

I don’t understand the relevance other than number of SMs, RT and tensor cores, or if they’re built on different nodes. The fact that 3070 has the same number of cores as a 2080 super and 3080 has the same number of cores as a 2080 ti confuses me because the power consumption difference has grown to 100W. I can only understand it if the 3080 has a greater ratio of RT and tensor cores, or if it’s built on a much worse node.
 
I can sort of see the 3080 to 3070 power draw difference. On memory bandwidth alone, you have 25% more from extra channels which also use GDDR6X vs 6, which is 48% more data being moved around. Add in more SMs running at a higher clock.....

50% of 220W = 110W + 220W = 330W. So given the alleged specs, the power difference seems reasonable. But the 3080 providing 50% more performance over a 3070 seems like an unusually large gap.


EDIT:

If one looks at the chip tier list, it makes a bit more sense:

Titan -> 3090 (very large chip)
Ti -> 3080 (very large chip)
*80 -> *70 (large chip)
 
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@ninelven yah looking at it the 3070 will probably have roughly 2/3 the number of cores. So the numbers start to line up. 2070 to 2080 (edit: wrote 3080 here) was about 4/5.
 
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se-filtra-la-zotac-gaxojto.jpg


Zotac RTX 3090
https://www.hd-tecnologia.com/se-filtra-la-zotac-gaming-geforce-rtx-3090-trinity-holo/
 
Seems to be 2+ thick but can be used vertically thanks to 2slots bracket.

Yeah the angle threw me off. It's probably pushing 3 slots like most big AIB cards.

It'll be interesting to see how the founders edition compares in temps and clocks. Nvidia is jumping through all sorts of engineering hoops on the FE version but so far AIB models look like standard fare.
 
One of the twitter leaker wrote that the 3090 (82SMs, 24GB, 920GB/s) has 350W and the 3070(TI) with 3072 cores has 250W. That would put the 3090 in another efficiency league than the 3070(TI)...
For comparision: RTX2070FE had a 175W TDP and the RTX2080TI FE 270W. The difference was bigger...


A 3070 ti would make a lot of sense, because there's a perfect spot at 270W to fit another card into the lineup.
 
It only becomes an issue if AMD comes up with something as fast or faster and more power efficient. Especially for mobile.

I'm thinking this is very possible for non-DXR/RTX games. Transistor density has increased much more than the SM count has. I have a feeling a lot of that is going to RT cores and tensor cores, but hopefully a good chunk to making the SMs wider, or something that can improve general compute performance. I have a feeling ampere will show great improvements in RT performance, especially with DLSS, but performance in non-DXR/RTX games will not improve as greatly. In a sense, like RTX 20x0 series, I think they're betting on the future. Curious to see how it plays out with UE5 and Cryengine, which seem to be doing things like GI without using DXR on PC.
 
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