05-08-2019, 07:34 AM
https://www.extremetech.com/gaming/29091...070-at-339
Quote:Hot Hardware reports on rumors that the Radeon RX 3080 XT will match the performance of the GeForce RTX 2070, but undercut that GPU on price, coming in at $330. This, of course, would match the old price on the GTX 1070, and might be read as AMD “restoring” the GPU market to its original, pre-RTX configuration.
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I’m skeptical of this claim for several reasons. First, it implies that AMD made a decision to build two different GPUs around a very narrow difference in core count. A 56 CU Vega 10/RX 3080 XT would have 3,584 GPU cores. A 60 CU Navi 20 (hypothetically branded as the RX 3090) would be 3,840 cores. That’s just a 7 percent difference in core count. Even if AMD goes for higher numbers of cores per CU (say, 128 instead of 64), the percentage gap between the absolute core count won’t change. While Nvidia used separate physical GPUs for the RTX 2070 and RTX 2080, the RTX 2080 has 1.27x more GPU cores than the RTX 2070. It seems unlikely that AMD would build two completely GPU designs solely on the basis of a 7 percent core difference.
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If AMD undercuts Nvidia’s GPU pricing and does so with GPUs that lack ray tracing, it could be read as a tacit admission that Nvidia has established ray tracing as a feature that customers will pay more for. When AMD introduced Radeon VII, it deliberately didn’t price that GPU any lower than the RTX 2080, despite the fact that the Radeon VII completely lacks ray tracing. It is possible that the company will do something similar here, or choose to split the difference by pricing below the equivalent RTX GPU it intends to compete with, but not so low as to imply that Nvidia has properly priced in the value of ray tracing. Despite reports that the PS5 will feature ray tracing, we’ve heard nothing about Navi 10 supporting this feature. And AMD has said it wants to wait to introduce RT until it can introduce it at the top to bottom of the stack. That could mean AMD is keeping quiet about ray tracing support on 7nm — or that it doesn’t intend to introduce the feature in 2019.
But as it stands, this rumor is, at best, incomplete. It implies an odd pricing structure that would require AMD to hit much higher clocks on GCN than it has ever demonstrated a capability to hit. The core counts also imply that AMD is relying heavily on efficiency gains to hit its performance targets, but efficiency gains in GPUs have been hard to come by of late. Vega was not, generally speaking, a large efficiency gain over previous versions of GCN. Could Navi change that? Yes. But historically, we’ve seen GPUs gain the most performance either by clock boosts (which GCN hasn’t been very good at) or core count increases (which this rumor implies have not occurred).
If this rumor is accurate, AMD either substantially improved Navi GPU innate efficiency compared with previous iterations of GCN or will content itself with slashing price, but not necessarily driving performance higher, with top-end performance at $500 that would still be below RTX 2080 Ti (albeit at a vastly lower cost). The proposed price structure makes limited sense without massive clock increases to drive performance in the upper tier products. And finally, it’s not clear why AMD would build two completely different chips between Navi 10 and Navi 20 if the difference between the two is just a 7 percent core count increase. This is much less of a gap than exists between the various Nvidia GPUs in their respective brackets and custom designs.