AMD: Pirate Islands (R* 3** series) Speculation/Rumor Thread

no-X said:
Thank you. Do you have any idea, what could be those two rectangles at the right border of the GPU?
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The PCI Express Interface probably? I was pondering too, if that were additional memory controllers, but they do look very different from the ones that are aligned with the L2-Caches at the side of the CUs. I don't think that AMD went through the trouble of designing different memory controllers for one chip.

The rotated position in which Tonga is mounted on the PCB does imply that it might be a shorter routing from the short side to the PCIe connector as well.
 
CarstenS said:
The PCI Express Interface probably? I was pondering too, if that were additional memory controllers, but they do look very different from the ones that are aligned with the L2-Caches at the side of the CUs. I don't think that AMD went through the trouble of designing different memory controllers for one chip.

The rotated position in which Tonga is mounted on the PCB does imply that it might be a shorter routing from the short side to the PCIe connector as well.
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The area is far too large to be the PCI Express interface.
 
Q5MVBsz.jpg


All the six GDDR phy clusters are visible. The display interfacing is at the lower left edge, the PCI-E is north of that.
 
I still fail to see where you see addtional MCs. I'll concede that they have approx. the same size, yes. But a visually totally different structure.

Nh3Qjtb.png
 
I stand corrected. Thanks for pointing that out :)

Even more impressive by AMD to increase the transistor and functional density without sacrificing other important things! I updated my article accordingly.
 
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A 384 bit 32 CU Tonga could have done significantly more damage than the current 285.

Why did AMD not release it right away?
 
Looks like Tonga is essentially Tahiti, with an updated ISA and double the setup pipes. The command processor is also quite a bit larger. And it took the the more compact memory phy padding from Hawaii, to cut down on the die-size.
 
Why go 384-bit on Tonga if you're not increasing shaders or ROPs? Unless AMD are upping the ROPs to 48(which imo should've been on Tahiti) or 64(staggered again?) or 96(which sounds la-la land).

And TR's Scott Wasson vindicated,

Another question these numbers raise is whether Tonga natively has a 256-bit memory interface. Generally, the size of a chip like this one is dictated by the dimensions of the I/O ring around its perimeter. Since Tonga occupies almost the same area as Tahiti, it's got to have room to accommodate a 384-bit GDDR5 interface. Surely we'll see a Radeon R9 285X card eventually with a fully-enabled Tonga GPU clocked at 1GHz or better. If I were betting, I'd put my money on that card having a 384-bit path to memory.
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RecessionCone said:
That way the rebrand into R9 380X comes with something new?
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Or because the channel inventory for Tahiti was in the stratosphere? I think that makes more sense. I don't see why one would leave a considerable amount of money on the table for over 10 months just to make a lineup look better. Especially since it was already a bit of disaster anyway... The other reason would be yields, but that's not very realistic either for 28nm.
 
fellix said:
Looks like Tonga is essentially Tahiti, with an updated ISA and double the setup pipes. The command processor is also quite a bit larger. And it took the the more compact memory phy padding from Hawaii, to cut down on the die-size.
Click to expand...
Are there ECC-enabled Tonga derivatives as well? I am not sure right now.


WRT to why AMD did not yet release a „full Tonga“: Until a few weeks back, R9 280-cards were priced VERY compellingly here in germany, probably clearing stock from the channel. That might have played a role.
 
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