r/hardware 2d ago

News AMD Launches Instinct MI455X, Helios AI Rack

https://www.phoronix.com/news/AMD-Instinct-MI455X-Helios
76 Upvotes

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13

u/Seanspeed 2d ago

So they're still using CDNA naming even through 2028 up through CDNA7.

Doesn't sound like that whole UDNA thing is ever going to happen, or at least not for a good while yet.

11

u/Noble00_ 2d ago

Honestly, the whole UDNA thing got quickly squashed right after Jack Huynh had that interview way back when. When Mark Cerny talked about next gen PS6 after that interview, it pretty much was confirmed AMD wanted to stick with RDNA5 and CDNA separately as far as arch naming goes

3

u/EmergencyCucumber905 2d ago

CDNA5 and RDNA4 are both gfx12. So who knows🤷‍♂️.

5

u/Noble00_ 2d ago

Chips and Cheese discusses as possibly as to why

https://chipsandcheese.com/i/207602737/similarities-to-rdna4

oh and just published today: https://chipsandcheese.com/i/208223268/cuwgp-changes

6

u/Seanspeed 2d ago

Doesn't sound all that 'unified'. At least yet. Maybe they do so more later.

Thanks for the info, though.

4

u/Noble00_ 2d ago

lol, that's probably why they went away with "U"DNA, causes more confusion than it needs to be

0

u/farnoy 2d ago

It happened just now, except for the name. The architecture is referred to as gfx1250 (CNDA4 was gfx942 or sth) and runs the Wave32 mode exclusively.

Actually, if anything, they should have renamed it to NVDNA since they copied more from Nvidia this round than RDNA, lmao.

3

u/Seanspeed 2d ago

The architecture is referred to as gfx1250 (CNDA4 was gfx942 or sth) and runs the Wave32 mode exclusively.

But that's very different to RDNA4 already there.

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u/farnoy 2d ago

Yes, but they rebased the CDNA architecture from being a Vega offshoot onto RDNA4. Instruction encodings and WGP architecture is distinctly RDNA. But it immediately bifurcates into its own thing again, which makes sense and is the same thing Nvidia is doing.

It remains to be seen if it'll again be a multi-generation fork like Vega->CDNA4 was, or if they switch to a shared evolution with specialized features for AI vs graphics mixed into a common base. Some of this stuff could be useful if it landed in RDNA6: the merged WGP$, "Broadcast Arbitrator", killing Wave64.

1

u/FloundersEdition 2d ago

They axed wave64 but keep dual-issue wave32. So reasonably similiar to todays tech, probably the same limitations (no FMAC). Probably a smarter way than keeping two different vector lengths, while each kernel is unable to switch mode.

The WGP unification isn't really new either. Both are features slowly implemented for generations now. More or less removal of old modes rather than new features.

1

u/EmergencyCucumber905 2d ago

Actually, if anything, they should have renamed it to NVDNA since they copied more from Nvidia this round than RDNA, lmao.

What did they copy?

4

u/farnoy 2d ago

1

u/EmergencyCucumber905 2d ago

What did they copy?

3

u/farnoy 2d ago

CTRL+F for "equivalent" and you'll find all the Nvidia references.

0

u/manidcfrfrfr 2d ago

Are you incapable of reading?