AMD's Navi GPU architecture might be powering their current gaming graphics cards but the red team might also be working on a separate line of GPUs for AI and HPC markets, one that would be replacing the Vega GPU based Radeon Instinct Lineup in 2020.
AMD Arcturus GPU Listed For Support, Possible Next-Gen Radeon Instinct 'MI100' HPC / AI Accelerator With Launch in 2020
The AMD Arcturus GPU is the one we are talking about and it has shown up in leaks quite a few times. The Arcturus GPU first appeared back in 2018 through Linux (Phoronix Forums) and was later confirmed by an AMD employee that they will be using designated codenames for the chip itself rather than using family-codenames that might expose the product/marketing name. AMD Arcturus GPU will be the first to fall in that line but at the time, other details were not mentioned.
Yesterday, HWiNFO added preliminary support for AMD Arcturus in its latest v6.13-3945 BETA release. In addition to that, Komachi_Ensaka revealed a series of chips that are marked under AMD's AI family and Arcturus seems to be one of them. The AI family also includes other GPUs such as Vega 10, Vega 12 and Vega 20. Judging by the AI name, the list might be mentioning the AMD Radeon Instinct based GPU accelerators as all three Vega GPUs listed have been featured inside a Radeon Instinct graphics cards for HPC and Artificial Intelligence. Arcturus also falls in the same list but looking at how the chips are mentioned in top-down order, the ones at the bottom for each family are also the latest additions to each specific lineup.
LLVM 9.0 also featured support for Arcturus which is rumored to be branded under the GFX9 (GFX908) family which are Vega parts but considering this would be a new launch, something needs to be changed if AMD isn't planning a simple rebrand of their top Vega Radeon Instinct accelerator in 2020. The same Linux Patch (LLVM 9.0) also listed down three SKUs, & did mention GL/XL brandings. So for instance, AMD has Vega 10 which are featured on the Radeon RX Vega 64 and RX Vega 56 graphics cards. They both use the same GPU but different variants with different core configs with the Vega 64 featuring the XT and the Vega 56 featuring the XL variant.
We have only seen little details which are also speculation at best such as the GPU cache info that is part of the Virtual CRAT (vCrat) size. The GPU cache correlates with the CU count. In the case of AMD Arcturus GPU, the cache size has been increased and so have the CU count from 64 to 128. That is twice as many CUs as Vega 10 which would give us 8192 stream processors if AMD is using 64 stream processors per CU like their current and modern-day GPU designs. Now AMD already released their Radeon Pro Vega II workstation series cards but remember, they are aimed at the workstation market and are based on Vega 20, a chip that is clearly mentioned in the list above. It is not to be related to Arcturus which is a separate part/chip and aimed at a different market, AI.
We know that AMD has rDNA 1 GPUs planned for the next few quarters before moving to rDNA 2 which is basically Navi 2 if rumors are accurate. Now Navi is from the ground up a gaming-oriented architecture first and the deployment in consoles and gaming graphics cards is evident of that. It is why AMD still uses Vega to power its HPC / AI stuff as it was designed for HPC / AI in mind.
So if AMD wants to continue with Vega architecture as their top design for HPC / AI accelerators, than Arcturus can be a fully custom-designed chip for the Radeon Instinct lineup. Over at his blog site, Komachi also posts more about the AMD Radeon Instinct MI100 which he believes is based on the Arcturus chips. AMD's current flagship Radeon Instinct accelerator is the MI60 which is based on the 7nm Vega 20 GPU. One thing that we may see happen is that since Vega saw a refresh from 14nm down to 7nm, Arcturus may bring the 3rd refresh down to 7nm+ which is something AMD is eyeing for 2020. Some of the new features that have been listed for the new Mi100 Radeon Instinct accelerator include the following:
XDLOPS & New Vector ALU & BF16.
Packed Math Ops -Float And Int.
Sq Exectuin Prefetch for shaders.
32/33/34/45 TCC & L2C.
8SE and CS launch Rate.
Cashe Hierachy Lantency
GDS (GWS / Ordered append).
— 比屋定さんの戯れ言@Komachi (@KOMACHI_ENSAKA) August 14, 2019
That's all as far as the details we have got on AMD's Arcturus chip. When it launches is something we would only know when it's officially revealed by AMD and given the specs, don't expect it to be introduced as a consumer gaming card as Navi has taken up that task.