AMD "Tonga" Silicon Features 384-bit Wide Memory Interface

[Kaapstad]

In what could explain the rather large die-size and transistor-count of AMD's "Tonga" silicon, compared to "Tahiti," it turns out that the silicon features a 384-bit wide GDDR5 memory interface, and not the previously thought of 256-bit wide one. The die is placed on a package with pins for just 256-bit, on the Radeon R9 285, but it can be placed on a bigger package, with more pins, to wire out the full width of the memory bus. This isn't the first time AMD has done something like this. Its "Tahiti LE" chip was essentially a "Tahiti" die placed on a smaller package with pins for just a 256-bit wide bus, on the oddball Radeon HD 7870 XT.

What this means is that AMD's next performance-segment graphics card based on the "Tonga" silicon, could feature 50% more memory bandwidth than the R9 285. The stream processor count is still 2,048, but these are more advanced Graphics CoreNext 1.2 stream processors, compared to first-generation ones on "Tahiti," offering more performance per Watt. The TMU count remains 128, although there's no clarity on the ROP count. Estimates are split between 32 and 48. The R9 285 has 32, and so does "Tahiti."

http://www.techpowerup.com/205811/amd-tonga-silicon-features-384-bit-wide-memory-interface.html

384bit bus and memory compression, this could get interesting.

 

[CAT-THE-FIFTH]

I assume that fully enabled Tonga will become the R9 370X then?? If the R9 380X is 20NM as the rumours indicate,that might end up making things look a tad weird for the AMD 300 series.

 

[old gamer]

im guessing amd are trying to get this out of the door to take on the 970, my guestiemate is performance will sit between the 970 and 980



might of cofused myself here , i thought this was a 20nm card

 

[almighty15]

384Bit with the new delta colour compression will be very interesting!

Doesn't AMD's new system give 30-40% more efficiency when it comes to bandwidth? That would enable a 384Bit card to have bandwidth like a 512Bit part.

I also do hope that the rumours of stacked VRAM are true for the higher end cards.

We also need to see 4Gb standard for mid-range cards and 6-8Gb becoming the standard for higher end parts.

 

[CAT-THE-FIFTH]

I suspect it will be either 3GB or 6GB versions of the card.

 

[TonyTurbo78]

3GB ppffftt

 

[~Mike~]

I suspect it will be either 3GB or 6GB versions of the card.

Hopefully 6GB.

 

[humbug]

384Bit with the new delta colour compression will be very interesting!

Doesn't AMD's new system give 30-40% more efficiency when it comes to bandwidth? That would enable a 384Bit card to have bandwidth like a 512Bit part.

I also do hope that the rumours of stacked VRAM are true for the higher end cards.

We also need to see 4Gb standard for mid-range cards and 6-8Gb becoming the standard for higher end parts.

Yeah, with the Tessellation performance it should be about 30 to 50% faster than the 280X, which would put them around GTX 970 Performance.

 

[bru]

Not being funny or trying to diss AMD, Why haven't we seen anything from AMD about this. The slide in this article is from Hiroshige goto not AMD, so personally I'm very sceptical until AMD themselves tell us this is the case.

 

[CAT-THE-FIFTH]

Not being funny or trying to diss AMD, Why haven't we seen anything from AMD about this. The slide in this article is from Hiroshige goto not AMD, so personally I'm very sceptical until AMD themselves tell us this is the case.

Its been hinted by a few of the review sites(they are under NDA though),and the GPU is quite big for the specs of the R9 285 it appears.

 

[LambChop]

Look like AMD keep rolling out the big buses, maybe they should look up what efficiency means.

 

[bru]

Its been hinted by a few of the review sites(they are under NDA though),and the GPU is quite big for the specs of the R9 285 it appears.

Ok fair enough, the next Question is Why?

Why would AMD Design a Tahiti replacement that is going to be a midrange part, take the time to bring the new compression stuff to the table making it about 25% more efficient in its memory bandwidth needs and then completely make the whole process a waste by using a 384bit bus anyway.

It is never going to be an Hawaii replacement it is just not fast enough.

A 384bit bus make no sense on this chip.

 

[humbug]

Ok fair enough, the next Question is Why?

Why would AMD Design a Tahiti replacement that is going to be a midrange part, take the time to bring the new compression stuff to the table making it about 25% more efficient in its memory bandwidth needs and then completely make the whole process a waste by using a 384bit bus anyway.

It is never going to be an Hawaii replacement it is just not fast enough.

A 384bit bus make no sense on this chip.

Why would AMD Design a Tahiti replacement that is going to be a midrange part

It is never going to be an Hawaii replacement it is just not fast enough.

Is that a question or are you stating an opinion?

 

[David Bisset]

Look like AMD keep rolling out the big buses, maybe they should look up what efficiency means.

That'd be the same size bus as a 780 and a smaller bus size than AMD used previously.

Given the 970 & 980 look to suffer a small amount in high-res multi-way setups I'd say going smaller isn't necessarily a great thing for all situations. For a single-card setup or 'normal' resolutions I'd agree that 256 is fine especially with compression, but that doesn't cover all users or use cases. Personally I'd stick with 256bit but who can tell what will happen with e.g. increasing resolutions? Maybe we'll push on to 8k soon etc. As I don't buy top-end stuff it really doesn't impact me anyway I guess, I'll be using a sub-£200 graphics card in whatever my next build is too coupled with not that high a res monitor so it really won't impact me either way I guess.

 

[GoogalyMoogaly]

So a bus size of less than 512-bit?
I get the feeling people could be complaining abou that! Look what happened with Nvidias recent cards!
When Nvidia used a 384-bit it was a problem because it wasn't 512-bit.
When Nvidia used a 256-bit with compression it was a problem because it wasn't 512-bit.
Will AMD come under the same criticism or will a bus size of less than 512-bit become acceptable because 'compression'?

 

[humbug]

So a bus size of less than 512-bit?
I get the feeling people could be complaining abou that! Look what happened with Nvidias recent cards!
When Nvidia used a 384-bit it was a problem because it wasn't 512-bit.
When Nvidia used a 256-bit with compression it was a problem because it wasn't 512-bit.
Will AMD come under the same criticism or will a bus size of less than 512-bit become acceptable because 'compression'?

Thats ok, HBM is coming...

 

[triss]

Judge the cards when they come out imo , 900's seems to be doing better then a lot assumed they would these may well be the same. Only thing i hope is they are 6gb not 3gb

 

[stuie]

I cant imagine that they will be 3gb, in scrooge mcvida are putting 4gb on their cards. Im also hoping it will be 20nm too im hoping to pick up some super cheap 970 once all the 28nm stuff has blown over

 

[Mal X]

Look like AMD keep rolling out the big buses, maybe they should look up what efficiency means.

AMD are getting scared and need something to fill the gap between now and April ............... but it looks too late because most of us have already brought something

the only card that makes sense now is the 390X

 

[bru]

Is that a question or are you stating an opinion?

The question was in answer to response to CAT-THE-FiIFTH gave.

I am asking why would AMD make the new midrange Tonga a 384bit bus part when it isn't needed (even more so with the new compression) and it would encroach on their top end parts too much.