AMD: Navi Speculation, Rumours and Discussion [2019-2020]

It would be interesting to see the reception if those leaks are true and the deltas trend over to general game performance. What would people value more? A noticeable bump in rasterization or one in RT?

 

The problem is, one may become indistinguishable from the other as more and more games become RT enabled thanks to the consoles. It'll be a shame if Big Navi does hold up to these performance rumours but it let down in RT performance. I'll be genuinely torn as to which to get.

 

I'm in the same boat. I play competitive games where all I want is to be able to play 1440p240 with low settings, but when I play single player I'm going to be looking for 1440p120 with the ray tracing pizzazz.

 

RT +dlss is a good combo on Turing and Ampere. This is what Rdna2 will have to beat imo.

Anyway, can't wait for reviews...

 

AMD is a polygon monster. It has 8 Rasterizer at 2.3 GHz. When i see the values between the two benchmarks the old one (fire strike) was polygon bound, the newer benchmark (time spy) is shader bound. Intersting that AMD can ceep up with 5000 Shaders with Nvidiass 10.000 Shader.

 

Yah, I can see that perspective. Even though time spy has way more vertices and triangles per frame, the ratio is heavily skewed towards computer shader invocations, where in fire strike the ratio of compute shader invocations to triangles is massively lower.

Edit: It'd be interesting to know if there are enough vertices and triangles in fire strike to bottleneck before the rops max out your bandwidth.

 

Anybody understand this:

[PATCH] drm/amdgpu: correct the cu and rb info for sienna cichlid
https://lists.freedesktop.org/archives/amd-gfx/2020-October/055069.html

 

So were the Linux/Mac OS info about Cu/RBE incorrect?

 

Lol

 

Because they've been searching for a benchmark where the 6080 beats the 3080, and Firestrike Ultra is it? It's little different than Nvidia finding out gaming Ampere runs Doom Eternal super well, far better than the average uplift, and putting out a video benchmark of it after the announcement.

GPU archs seem to be diverging this year over what they run efficiently. There's a large disparity in performance gains per title for Nvidia and AMD both, and even Intel's HPG is fairly title dependent on performance versus the competition. So trying to go through recognizable titles seeing what works best more relevant than ever for PR.

 

Don't seem to understand this. Is there an issue with the 3DMark13 FireStrike benchmark?

https://www.3dcenter.org/news/hardware-und-nachrichten-links-des-22-oktober-2020

 

Depending on how far you want to go back: I remember the family party that was HD 2000 series.

3DCenter says Fire Strike is an overperformer by 19% with RDNA1 already, so this might carry to the next generation. They insinuate to not take RX 6000 perf in this particular benchmark as indicative for general performance. That's what I read from the original german posting.

 

Yes 5700XT does very well in FSU, though I don't think it's anywhere near 20%, that's probably a cherry picked AIB OC result. Average score is closer to 2070s. OTOH leaked score could be cherry picked AIB OC results too.

https://www.guru3d.com/articles-pages/xfx-radeon-rx-5700-xt-thicc-ii-ultra-review,22.html


Also what is up with that update patch and CU count? Jawed redemption arc or just BS?

 

I'd say it's nothing in particular, just a setup code for SKUs with different amount of shader arrays. It even says so in the next commit:

Skip disabled sa to correct the cu_info and active_rbs for sienna cichlid.

 

Ok, yeah it does state that the list of node pointers is provided to the CU so there should be no need to fetch them again.

The stack and result queues on Ampere are likely fixed size and relatively small. Nvidia's patent didn't make any accommodation for spilling out to memory so I assume AMD will handle edge cases more gracefully. Hopefully AMD goes into detail on the inner workings of their RT flow.

 

You don’t need a deep stack to efficiently handle traversal, whether it’s stored on dedicated memory, registers or cache.
For instance see this recent Intel paper:
https://software.intel.com/content/...es/wide-bvh-traversal-with-a-short-stack.html

Generally speaking a high performance SW implementation of BVH traversal on a GPU is probably not going to use a variable amount of state for the stack, as you want to avoid going off chip (and perhaps even off L2) and keep all of your data on registers and/or shared local memory.

 

3DCenter cites their calculation basis in their linked article. According to that, it's not an outlier or cherrypicked result, but an average FS Ultra score vs. their calculated 4K performance index, which is based on the results from Kitguru, Overclockers Club and Tweakers.

 

True but those recommendations are of course keeping in mind quality of PSU and possibility of being paired with a high power Intel CPU. With a 3900X, you shouldn't have any problem running either a 3070 or N22 (which I'd expect is <200W).

Since the consoles are based on RDNA2, the RT performance could actually be better on Big Navi in the long run as games could be optimized for it.

 

Seems to imply that Navi 21 is the only GPU where ROPs and shader arrays are disabled.

I wonder if ROPs are bound to shader arrays.

So Navi 21 could be 60 CUs (WGPs?) with 96 ROPs (48?) with a single shader array entirely turned off and the corresponding set of ROPs, too.? It would seem AMD has a choice of at least 8 shader arrays when choosing which one to turn off.

If Navi 2x GPUs have a monster last level cache, then consoles games will not be built to take advantage of it, because consoles don't have such a monster cache.

 

Performance drop off at 4K is pretty big for 5700XT. This is really not a 4K GPU. Even if 5700XT was as fast as 2080 in FSU on average which X doubt based on review that I posted, you are still looking at maybe 15% according to TPU at 1440p. which is a reasonable res to use.

But anyway, I agree that extrapolating any kind of gaming performance from leaked FSU scores with an unreleased GPU that appears to be a pretty BIG departure from RDNA1 is completely pointless.