Back to Top

AMD’s Arcturus GPU is Big Vega, y’know, for science

AMD 7nm Vega GPU

The AMD Arcturus graphics card codename has been bandied about for a while now, and the latest leak suggests it could be destined to play a starring roll in an upcoming Radeon Instinct MI100 graphics card. A BIOS file for said GPU, dug out by prolific leaker Komachi Ensaka on Twitter, promises a ginormous workhorse fit with over 7,000 stream processors (SPs) ready to take on Nvidia’s data centre Tesla chips.

Arcturus leaks have been around for a little under a year now, and we’ve known for some time that, whatever it may be, it isn’t intended for our gaming PCs. Sadly, Arcturus is without 3D engine, leaving it with just the silicon required for uber-parallel number-crunching favoured by AI and HPC applications.

So while gamers wait with bated breath for the Big Navi golden goose, HPC boffins will be living it large with a ‘Big Vega’ graphics card. That should come as no surprise as AMD insisted it would be holding onto GCN-based architectures for compute cards during the hand-over to the RDNA architecture for gaming chips.

It’s not going to be exactly Vega, however, and it appears some significant changes have been made to the GCN architecture with Arcturus.

The leaked MI100 will likely lead the Radeon Instinct lineup. With between 7,680-7,936 SPs, the MI100 will soar far above the 7nm Radeon Instinct MI60, a compute accelerator with 4,096 SPs. Previous Linux patch posts suggest this is achieved via a doubling of Compute Units (CUs) from 64 to 128 – thus dramatically improving raw compute performance.

The MI100’s GPU is listed as “A1 XL.” While unlikely at this time, that does leave the door open to an “XT” GPU later in life, perhaps one with the full 8,192 SP compliment. Three PCI device IDs have been found flying the Arcturus banner in the past, which suggests two further cards in the lineup may also be on the way.

While a little pricey for gaming graphics cards, such as the RX Vega 64 and RX Vega 56, high-bandwidth memory (HBM2) has proven worthwhile for accelerators. The MI100 is expected to be packed with 32GB of the stuff.

This will not be the first GCN card to make the change to 7nm, however. At the beginning of 2019, AMD released the gaming-focused Radeon VII as a prelude to AMD Navi, some of the best graphics cards for gaming, later that same year.

Of all of our guesses as to what the AMD Arcturus GPU is for, it now appears only one could potentially take form over the coming months. That would have Arcturus GPUs sitting within the Frontier Supercomputer, set to take the crown as the world’s most powerful in 2021, and built by AMD and Cray for the Oak Ridge National Laboratory.

We may find out a little more regarding Arcturus, and perhaps even Big Navi, over at AMD’s March 5 Financial Analyst Day. Stay tuned for the live stream closer to the day.

Back to Navigation