Xbox One (Durango) Technical hardware investigation

[Wynix]

And everybody else with some experience is saying don't rely on wishful thinking and speculation, because that road always ends in tears.

And what you're engaging in is wishful thinking and speculation. Hence, you're setting yourself up for disappointment.

Indeed it is speculation, that is pretty obvious, im unsure why that is discouraged in a thread about hardware investigation of a console where the specs are unknown.

The rumoured Durango GPU is not "roughly a 7770"... Yes the performance is, but there is a reason it's achieved by a totally different way, which is more CUs at significantly lower speed. Durango's CUs wont draw as much watts as 7770 or Bonaire. I don't have any problem believing that Durango's GPU will be based on GCN 1.1, but other than that, Bonaire is just one another configuration of that tech and isn't super important with regards to Durango, even if Durango has 14CUs, where two are disabled.

You appear to have misread my post, i never said it was using a 7770 or a 7790.

 

[Nisaaru]

I don't think its that simple.

The eSRAM is directly interface to what looks like pretty fast i/o bus with encoding and decoding logic on it. Durango might be designed to facillitate efficient servicing of outside devices like XTV, Kinect, display glasses, tabs or phones.

Do you really get the impression that they get the most out of the ESRAM?

The internal bandwidth of the GPU is designed to handle 128..384Bit GDDR5 memory systems(2..6 memory controllers) depending on the chip config. As the eSRAM is part of the GPU and not external why is it not connected with the whole internal bus width?
Why waste the only real advantage such a console design can give you over the same class of generic GPUs?

 

[DrJay24]

Because the 1.2Tflops rumour is just that, a rumour and 1.2Tflops GPU is roughly a 7770 which draws around 80W, the 7790 is just shy of 1.8Tflops and draws around 85W(while using much faster ram).

This combined with the fact that Sony has 1.84Tflops and MS having 1.2Tflops puts them way behind Sony and will make them look inferior, therefore it is entirely possible that the 7790 or something similar has made it's way into the NextBox at some point of it's development to narrow the gap between the two consoles.

I'm not saying it makes the rumours obsolete, but don't rely on old rumours too much.

Well without a tinfoil hat, we know VGAleaks has a recent (late 2012) MS document or dev kit and has been leaking the info piecemeal. So it is probably saner to believe in a solid leak than forum conjecture. The 7790 rumor is not based on any leak, it is literally just an idea floated here and spread around.

 

[function]

Do you really get the impression that they get the most out of the ESRAM?

The internal bandwidth of the GPU is designed to handle 128..384Bit GDDR5 memory systems(2..6 memory controllers) depending on the chip config. As the eSRAM is part of the GPU and not external why is it not connected with the whole internal bus width?
Why waste the only real advantage such a console design can give you over the same class of generic GPUs?

Isn't sram supposed to be lower bandwidth than dram? It might be that the sram macros simply don't have the bandwidth. As it is, Durango seems to have something like 4 times the bandwidth of Bulldozers L3, which perhaps isn't surprising as it's 4 times the size.

Perhaps texture reads and depth reads will be the real gain from Durango esram and not colour buffer writes (which can go in DDR3 if needed). If low latency helps GPU and maybe even CPU efficiency then that could be a bigger win than huge amounts of bandwidth.

And again, if you compare Durango to 7770, 7790, Trinity, Richland, PS4, etc then the BW figures for Durango don't look bad at all. It's got far more BW per flop, TMU or ROP than high end Trinity even without the esram. If you include the esram, and assume that most of that BW is achievable and most of it won't be wasted with copy then it's probably going to be fine.

 

[DuckThor Evil]

You appear to have misread my post, i never said it was using a 7770 or a 7790.

Lol...

What's this then?

it is entirely possible that the 7790 or something similar has made it's way into the NextBox

That wasn't my point anyway. You were trying to make a connection that Durango's GPU draws about the same as 7770 and that's why using a 7790 would make more sense as it draws hardly any more. I just pointed out that the CUs in Durango wont draw as much as either of those GPUs and that's why your reasoning of it possibly having a more beefed up GPU is based on a totally false premise.

The only way for the next Box to have a more powerful GPU is if they have raised their power consumption limits from what a 12 CUs at 800Mhz draws, that could be possible, but so far nothing points that they have done so. A 7790 or any new PC GPU doesn't change that in any way. MS has had all the information about AMDs possible solutions and they've had the building blocks at their disposal, their decision has likely been made long time ago.

I think quite a few people here have some weird understanding problem on this situation...

 

[SenjutsuSage]

Lol...

What's this then?



That wasn't my point anyway. You were trying to make a connection that Durango's GPU draws about the same as 7770 and that's why using a 7790 would make more sense as it draws hardly any more. I just pointed out that the CUs in Durango wont draw as much as either of those GPUs and that's why your reasoning of it possibly having a more beefed up GPU is based on a totally false premise.

The only way for the next Box to have a more powerful GPU is if they have raised their power consumption limits from what a 12 CUs at 800Mhz draws, that could be possible, but so far nothing points that they have done so. A 7790 or any new PC GPU doesn't change that in any way. MS has had all the information about AMDs possible solutions and they've had the building blocks at their disposal, their decision has likely been made long time ago.

I think quite a few people here have some weird understanding problem on this situation...

True, and I'm completely fine with their GPU as it is now. I don't think they desperately need something stronger, but until Microsoft officially reveals what their more current plans are, of which all the rumors we have currently certainly can't be 100% described as such, we technically also can't say that they haven't been willing to increase their power consumption.

 

[Cyan]

Speculation only.

I am not sure it's only speculation, especially when the article says something that makes a lot of sense to me.

In the creation of Bonaire, AMD might be using functional parts and designs of other GPUs that have been proven to work well, and the numbers are so similar to Durango's GPU that I wonder if it's not based on it, and if the extra MHz aren't used to "emulate" the console GPU which, unlike a PC, doesn't have to handle layers like HAL and draw calls.

It’s no coincidence that Bonaire answers some of the questions we had after the Xbox Durango GPU leak early last month. According to VGLeaks’ data, Durango’s front end was capable of issuing up to two primitives per clock like Tahiti and Pitcairn, but the memory bandwidth figures pointed to a 128-bit bus. Now we have Bonaire — a 128-bit GPU that merges those two capabilities in a single part.

Spinning a new GCN part for Microsoft allows for a smaller die, lower manufacturing costs, and explains why AMD CEO Rory Read calls AMD’s console SoC’s “semi-custom” designs. It makes no sense for AMD to build and launch another GCN part just to hit a market target — but it makes a lot of sense for a cash-strapped company to design a new GPU that can target multiple markets simultaneously.

 

[Cyan]

The rumoured Durango GPU is not "roughly a 7770"... Yes the performance is, but there is a reason it's achieved by a totally different way, which is more CUs at significantly lower speed. Durango's CUs wont draw as much watts as 7770 or Bonaire. I don't have any problem believing that Durango's GPU will be based on GCN 1.1, but other than that, Bonaire is just one another configuration of that tech and isn't super important with regards to Durango, even if Durango has 14CUs, where two are disabled.

If we take the numbers into account I would say that Durango's GPU is the key evolution piece from the 7770 to the 7790. If we take into account the equivalent GPUs in the PC world, we get something like this:

Low end: less than 7770
Mid end: 7770, 7790, 7850, 7870
High end: 7950 7970
Enthusiast gamer: 7990 and above

At least as it stands right now.

I think that Bonaire is basically the "same" GPU in nextxbox, it's almost a perfect match. The thing is that being in an APU means it can get downclocked, just like low-power or low-cost, or also a mobile laptop variant. And that's the only difference you can find in it, if you ask me.

 

[Grall]

I think that Bonaire is basically the "same" GPU in nextxbox, it's almost a perfect match.

Right, perfect match. Apart from the eDRAM of course, the data move engines and the display planes thingamajiggies, and whatever other modifications were thrown in there and simply never publically disclosed... Yes, perfect.

It's not the same GPU. Just face facts, okay?

 

[astrograd]

Right, perfect match. Apart from the eDRAM of course, the data move engines and the display planes thingamajiggies, and whatever other modifications were thrown in there and simply never publically disclosed... Yes, perfect.

It's not the same GPU. Just face facts, okay?

1) The DME's, DDR3 RAM and eSRAM seem like they could be conjugates of normal DMA's, GDDR5 RAM and eDRAM. You want the GPU to see a certain bandwidth and those are two solutions to get the same outcome. The former works well with MS's goals for their platform, the latter is perhaps better suited for a wider range of PC's.

2) The display planes are totally separate things that AMD likely had nothing to do with (it's distinctly MS tech). It isn't entirely clear how flexible they are in terms of letting devs move resources from one plane to another.

3) I think the numbers match well enough that it sounds likely that AMD based their design for 7790 on Durango's GPU. They probably just adjusted their memory management setup a bit and changed the clocks. Is there anything else going on? 7790 gets 1.8Tflops at 1GHz. Durango's GPU would "only" get 1.54Tflops at that clock. The 2 extra CU's maybe?

 

[SenjutsuSage]

Why does it being an APU mean it can get downclocked? Couldn't it have been downclocked regardless? Are there some extra advantages of an APU that make the downclock less significant, or what?

Durango's gpu and the 7790 are clearly very similar. There's nothing else on the market quite as identical. The Durango GPU is just slightly different and modified, but they are very similar.

 

[AlphaWolf]

3) I think the numbers match well enough that it sounds likely that AMD based their design for 7790 on Durango's GPU. They probably just adjusted their memory management setup a bit and changed the clocks. Is there anything else going on? 7790 gets 1.8Tflops at 1GHz. Durango's GPU would "only" get 1.54Tflops at that clock. The 2 extra CU's maybe?

1.79TF * .8 (800Mhz) *12/14 (number of CUs)= 1.23TF

Surely just coincidence.

 

[function]

There's quite a spread of cards now, so it shouldn't be a surprise anyone that some of them come in kind-of-close to the Durango GPU is some way. I don't think AMD needed Durango to work out that the PC GPU market has space for a card with the 7790s characteristics (especially seeing as how it's different). AMD also have parts just below Durango (the 1.28TF 7770), and just above the 7790 with the 7850.

 

[arijoytunir]

if microsoft wants the most efficient gpu then they might have taken the 12 cus from an amd mobile gpu .

 

[Betanumerical]

The rumoured Durango GPU is not "roughly a 7770"... Yes the performance is, but there is a reason it's achieved by a totally different way, which is more CUs at significantly lower speed. Durango's CUs wont draw as much watts as 7770 or Bonaire. I don't have any problem believing that Durango's GPU will be based on GCN 1.1, but other than that, Bonaire is just one another configuration of that tech and isn't super important with regards to Durango, even if Durango has 14CUs, where two are disabled.

I was under the impression that GCN1.1 bought to the table multiple ACE's (something along the line of 8) where as every diagram and every bit of information we have so far has shown us that Durango only has 2.

 

[scently]

I was under the impression that GCN1.1 bought to the table multiple ACE's (something along the line of 8) where as every diagram and every bit of information we have so far has shown us that Durango only has 2.

Bonaire has 2 ACEs. The 8 ACEs seems to be unique to the PS4.

 

[Betanumerical]

Bonaire has 2 ACEs. The 8 ACEs seems to be unique to the PS4.

Does that mean that Bonaire is GCN1.0, its a question that seems hard to get a answer for .

 

[AlphaWolf]

if microsoft wants the most efficient gpu then they might have taken the 12 cus from an amd mobile gpu .

Mobility parts aren't really unique, their efficiency is achieved through binning. While console parts may also strive for great perf/watt, binning isn't possible. They will likely aim for lower clocks because of that goal of high perf/watt, but they need the vast majority of silicon produced to be able to hit the target.

Durango will be a unique APU, and while the GPU portion may bear the most resemblance to a certain PC part, I doubt it matters as it is probably still somewhat different.

 

[AlphaWolf]

Does that mean that Bonaire is GCN1.0, its a question that seems hard to get a answer for .

AMD has not distinguished it from a GCN part, but it has differences from previous parts. I don't think you'll hear AMD calling anything GCN 1.1, but some websites have given this designation to bonaire.

 

[SenjutsuSage]

I was under the impression that GCN1.1 bought to the table multiple ACE's (something along the line of 8) where as every diagram and every bit of information we have so far has shown us that Durango only has 2.

I don't think we've ever actually seen a diagram that tells us that much. We have a lot of info on the Durango GPU, but I don't think we've ever been given that in depth a detailing of all that it does.

The Durango GPU info has never gone that low level, to the point that we were exposed to the layout of the GPU's queues and pipelines, so I think we have no idea what it really looks like in there, whether its the same as your typical GCN GPU or whether there are changes like those described in the PS4 GPU.

I wonder if these console APUs will support turbo for both the CPU and GPU if either part isn't hitting all their allocated TDP? That would certainly be interesting. Maybe that's why they are both being clocked as low as they are, on both the CPU and GPU side? In such a case, it might not be such a bad thing that you have a pretty low TDP to start out with. Or maybe this is simply disabled or not present on the consoles?