Nvidia RTX 3080 and Ampere: Everything We Know

[harlan4096]

Here's what we know and what we expect from the Nvidia RTX 3080 / Ampere GPUs.

Nvidia's Ampere architecture will be the next major upgrade for GPUs from Team Green, and will find its way into the upcoming GeForce RTX 3080 Ti, RTX 3080, RTX 3070 and RTX 3060 graphics cards. Or perhaps Nvidia will throw us all a curveball again and change the model numbers. Whatever. The GPUs should rank high on our GPU hierarchy and list of the best graphics cards. We know Ampere is coming, and Nvidia CEO Jensen Huang is set to deliver a keynote on May 14 that will get us all "amped" for Nvidia's latest technologies. Here's what we know about Ampere, including potential specifications, release date, price, features, and more.

First, it's important to note that all of the rumors and leaks of the past year or so are unconfirmed, and any claims of pricing are complete fabrications/guesses.

No GPU company releases pricing details months in advance of a product's launch. Nvidia is very tight lipped about what it's working on, and the transition from the Turing to Ampere architecture is going to be particularly big for the company. Nvidia won't say anything publicly until just before launch, so potentially next week we'll have some concrete details (at least on GA100).

We're as excited as anyone about Nvidia's next generation GPU architecture, but we also want to separate fact from fiction. There's precious little of the former that can be proven, and potentially plenty of the latter, so take everything with a grain of salt. Let's also point out that Ampere is critical for Nvidia, on many levels. Recently, in it's Super Spring laptops announcement, Nvidia revealed that "15 million RTX GPUs" have been sold. That sounds nice, but damn if that doesn't seem awfully low for a GPU architecture that's been around for over 18 months.

The problem is that Nvidia doesn't normally provide hard data on the number of units sold. The current Steam Hardware Survey suggests that there are about four times as many GTX 10-series GPUs in the wild as RTX 20-series GPUs, but the statistics behind Steam's survey are opaque at best so we can't be too sure about real figures. Regardless, the attitude of many with RTX 20-series was to "wait and see," with the sage advice being that the first generation of any new technology — ray tracing hardware, in this case — might be interesting, but generation two will be where it really takes off.

Ampere is ray tracing Gen2, in other words, and after a relatively slow start for ray tracing hardware and the RTX 20-series (from our perspective), Ampere has a lot to prove. The RTX 3080, RTX 3070, etc. (which is what we're calling them for now) need to provide not just better performance in games using traditional rendering techniques, but a dramatic increase in ray tracing performance would open the doors to doing more RT effects without tanking performance.
Nvidia GeForce RTX 3080 and Ampere At A Glance: 

• Up to 128 SMs / 8192 GPU cores (for RTX 3080 Ti)
  
• The GPUs should be much faster than the RTX 20-series
  
• Nvidia's first 7nm part should be much more efficient than Turing
  
• Release Date: We expect to see Ampere in 2020, probably fall
  
• Price: RTX 3080 likely to cost around $699-$799 (but we hope it's lower)
  

Let's be real clear on this: We don't know for certain what Nvidia is going to change with the Ampere architecture. The only expectation is that it won't be a simple die shrink of Turing from 12nm to 7nm. Beyond that, there are many things Nvidia can potentially do to make the RTX 3080 and other Ampere GPUs better. Here's the quick roundup of some of the rumors.

First, the fundamental building block of Nvidia GPUs is called a Streaming Multiprocessor (SM). Its AMD analog is the Compute Unit (CU), and at a high level, it's relatively safe and easy to compare the two companies' GPUs based on SMs vs. CUs. The Turing architecture brought plenty of changes to the SM configuration, and it's a safe bet that Ampere will bring additional changes.

Turing added RT cores and Tensor cores, for ray tracing ray/triangle intersection calculations and deep learning FP16 calculations, respectively. Beyond the RT and Tensor cores, the CUDA core is the major GPU hardware in Nvidia graphics cards. For Turing, Nvidia switched from having 128 CUDA cores per SM to 64 CUDA cores. Turing also added a dedicated integer (INT) pipeline to each CUDA core, which allows for concurrent INT and FP (floating-point) calculations.

Previously, a shader core would have to switch from doing FP to doing INT, which reduced overall efficiency and throughput. The Turing CUDA cores also added support for rapid packed math (FP16) calculations, which basically double the computational power of FP32 but with reduced precision — FP16 is useful for certain types of calculations.

We're really condensing everything that changed with Turing here, but beyond the above, there were changes to the L1/L2 cache, support for Variable Rate Shading (VRS), mesh shaders, Texture Space Shading (TTS), Multi-View Rendering (MVR), and enhancements to Simultaneous Multi-Projection (SMP). Most of those are now part of the official DirectX 12 Ultimate API, and also have support in VulkanRT. Oh, and the NVENC hardware got a major upgrade that added hardware accelerated encoding and decoding of higher resolutions and more codecs like VP9 and HEVC.

Conventional wisdom is that it's not a great idea to do massive architecture changes at the same time as a major change in lithography. Nvidia is already doing the lithography change going from TSMC 12nm FinFET to TSMC 7nm FinFET, so perhaps there won't be as many architectural changes as in Turing. However, we do expect the ratios of the various core types in the SM to be altered.
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