AMD’s next-gen ‘Super Secret’ Navi GPU teased

AMD might be an entire generation behind with their Vega GPU architecture, but their next-gen Navi GPU architecture is due sometime in late 2018 and has turned up as the elusive “Super Secret” ID in AMD’s new driver.

AMD’s GPU Architecture Roadmap for the upcoming years

In the latest AMD’s drivers, there is code that shows “new_chip.gfx10.mmSUPER_SECRET.enable[0:0]“. The Vega architecture is GFX9. Navi is GFX10, which is what gave this new “Super Secret” chip away.

There are also other interesting strings shown

umr -O bits -f @demo/npi/newchip -lr gfx10
+reg gfx10 mmSUPER_SECRET mmio 0x12345670
+bit gfx10 mmSUPER_SECRET enable 0 0
new_chip.gfx10.mmSUPER_SECRET => 0x12345670
new_chip.gfx10.mmSUPER_SECRET.enable[0:0]

Someone spotted the new Super Secret ID in the latest Linux release of Radeon drivers, but it could be Team Red having some fun with us. Navi could be the first GPU from AMD that would see a scalable GPU design being deployed, with many smaller Navi GPU dies interconnected through AMD’s super-fast Infinity Fabric technology. This means AMD could drop GPU cores from each die, resulting in less cores per die but multiple dies added together would give us a Threadripper-like GPU design.

AMD’s Navi Roadmap for next year

AMD has also told us that their Navi GPU architecture would use “NextGen Memory” which is unclear if it’s not only HBM3 or GDDR6. Considering AMD is already using HBM2 in their current fleet of Radeon RX Vega graphics cards, the shift to GDDR6 or HBM3 would be very interesting. GDDR6 would be in general cheaper to produce.

About the code? Traditionally, the Linux driver code would be updated using the bear names of upcoming graphics architectures and that’s usually how the hardware leak scene becomes aware of impending new GPUs. This time however the RTG software team’s use of “Super Secret” appears to be somewhat of a humorous attempt to keep the code name of this particular chip under wraps. This shown code is referring to one specific Navi chip – not an entire architecture.

Update

Phoronix is dispelling the story going around that AMD’s next-generation Navi GPU architecture is referenced in Linux driver code. The snippet cited, which is from a patch back in July, isn’t for the AMD Linux driver itself but UMR, AMD’s open-source GPU debugger, whose work began about a year ago.

The purpose of the patch in question isn’t about supplying Navi/GFX10 GPU support either. Rather, this patch is just about allowing arbitrary new GPU information from a file to this UMR debugger. Where the “gfx10 mmSUPER_SECRET” comes from isn’t even any code for the UMR debugger itself, rather just code added to a demo file for showing off and testing the new functionality for UMR.

Source

• AMD Navi spotted in Linux drivers (Videocardz.com)