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VGLeaks Rumor: Durango Memory System Overview & Example
- Thread starter Takuya
- Start date
phosphor112
Banned
It (the 7770) is also clocked at 1000Mhz as opposed to the 800Mhz that it's rumored at.
I'd say the benefits (in the long run) of having customized solutions (which bank efficiency) could imply that the GPU in XB3 (rumoured) may perform (given the two extra CUs as well) somewhere between 7770 and 7850. For the PS4, on paper it already bests 7850 and so there is a very realistic chance of it actually performing almost as well as 7870 (if not better).
dragonelite
Member
This is just a rehash of the leaks we already had?
Ol No Bones
Banned
they've also aimed for parity because developing on PS3 has been an uphill struggle, so reaching parity is an achievement.
its not that straightforward though. 7770 has only one triangle setup unit compared to two in the 7850. Durango is rumoured to have two as well, so that part of the architecture is not directly comparable to the 7770 architecture.
it sounds perhaps more like it could be a detuned 7850 with half the ROPs and fewer CUs. the rest of it sounds quite similar.
What would be the benefit in having two set ups in a closed box? The triangle set up for Django on paper is identical to PS4 at 1.6B/sec. So what is the other rumoured set up?
EDIT: Yes, I remember someone mentioning that it could actually be a detuned Pitcairn rather than tuned up Cape Verde.
Its the same because it has the two setup engines.
I am confused. The stock 7850 operating at 860Mhz is capable of outputting 1.72B poly/sec. At 800Mhz it drops to 1.6B. Are these values the "two set up" you're referring to?
the two setup engines, because its a pitcarin part and not cape verde like people originally though.
phosphor112
Banned
I totally forgot about that. Good reminder. Thanks.
The GDDR5 on the 7770 has a maximum bandwidth of 72 GB/s.
amstradcpc
Member
Each setup engine can proccess one triangle per cycle. So at 800Mhz per second it processes 800000 * 1 = 800000 triangles. You have 2 setup engines, so multiply 800000 * 2 = 1600000 triangles / second.
7770 has one triangle setup engine in it, which can do 1 triangle per clock.
7850 has two triangle setup engines, each of which can do 1 triangle per clock, for a total of 2 triangles per clock.
Durango GPU architecture leaks show it having two triangle setup engines and 2 tris per clock. So it can't literally be a 7770 architecture.
amstradcpc
Member
Yes, you are right, 1 MHz = 1.000.000 cycles.
Yes, I remember now. And you both are right (I just had a 'doh' moment). The Cape Verde 7770 does do 1B poly/sec at 1000MHz. Thanks for the succinct overview.
No
R10Neymarfan
Member
Nope. Hoping the custom GPU has the Tahiti architecture or something close to it.
LittleJohnny
Banned
Its not Tahiti, we know that for sure.
You really think MS would put together a harder to program for, weaker console? lol
specialguy
Banned
You guys are really taking this GDDR5 thing too far without understanding it. The 7770 stock has 72 GB/s BW with GDDR5. Basically the same as the rumored 68 GB/s the Durango has.
There's nothing that intrinsically makes GDDR5 better than DDR3, in fact it's worse because it has greater latency. GDDR5's benefit is it scales to higher BW.
Now, it is true Durango's CPU will share that 68 GB, but OTOH there's the ESRAM which makes it a whole nother ballgame.
Unfortunately, going by the leaks they seem to have done exactly that.
specialguy
Banned
But it has 16 ROPS like Cape Verde. Probably not a detuned anything, but it's own thing. Most of the stuff should be fairly modular. They would have had to do a fair amount of custom work for the memory interface of both consoles anyway, so it's not exactly like any PC part.
specialguy
Banned
I've been posting this stuff over B3D, but AMD has a new part supposedly to be coming in April, the "Bonaire" or 7790 GPU. It's supposed to slot between 7770 and 7850 on PC's.
Notable things about this guy are, it sports 768 SP's. Which is 12 CU's. In other words exactly what Durango is rumored.
http://translate.google.com/transla...radeon-hd-7790-bonaire-i-sweclockers-testlabb
Another thing is, it seems to be possibly clocked at 1075 mhz stock. The link calls it a overclocked model, but every spec sheet I've found claims 7790 is clocked at 1075 period (for example this link http://www.tomshardware.com/news/AMD-Radeon-7790-Saturn-GPU,21447.html ). Additionally a lot of links claim AMD wont allow overclocked 7790 so as not to encroach on 7850. Which would mean they all have to be the same clock.
So if 1075 is stock, I'm really hopeful for a Durango clock bump to at least 1 ghz.
There also seems to be some claims Bonaire is GCN 2.0, which is also interesting. If it's the same as PS4 it probably doesnt mean a lot though. It wouldn't surprise me.
Also another thing pointed out on B3D, 7790 spec sheet lists:
Is exactly the same as the Durango ESRAM BW I think. A little odd/coincidental anyway.
Notable things about this guy are, it sports 768 SP's. Which is 12 CU's. In other words exactly what Durango is rumored.
http://translate.google.com/transla...radeon-hd-7790-bonaire-i-sweclockers-testlabb
Another thing is, it seems to be possibly clocked at 1075 mhz stock. The link calls it a overclocked model, but every spec sheet I've found claims 7790 is clocked at 1075 period (for example this link http://www.tomshardware.com/news/AMD-Radeon-7790-Saturn-GPU,21447.html ). Additionally a lot of links claim AMD wont allow overclocked 7790 so as not to encroach on 7850. Which would mean they all have to be the same clock.
So if 1075 is stock, I'm really hopeful for a Durango clock bump to at least 1 ghz.
There also seems to be some claims Bonaire is GCN 2.0, which is also interesting. If it's the same as PS4 it probably doesnt mean a lot though. It wouldn't surprise me.
Also another thing pointed out on B3D, 7790 spec sheet lists:
Is exactly the same as the Durango ESRAM BW I think. A little odd/coincidental anyway.
phosphor112
Banned
So, it's settled, you think it'll be a more powerful and easier to develop for console.
No I think that's a ridiculous statement to make on Durango being harder to develop for with no basis at all.
Gemüsepizza
Member
No basis at all? What? The memory solution with DDR3/eSRAM etc. on the Durango seems to be definitely more complex than the unified RAM solution with only GDDR5 on the PS4. Add to that the relatively low power (=more optimization needed), and you have a console which is harder to develop for.
Gemüsepizza
Member
That's what the rumors say, yes. If you don't want to believe them, ok.
PS: I was talking about system architecture, not about "coding tools". Which btw. can be used to some extend by PS4 devs too (Visual Studio for example).
PS: I was talking about system architecture, not about "coding tools". Which btw. can be used to some extend by PS4 devs too (Visual Studio for example).
phosphor112
Banned
Boolean operators, how do they work? Your post had a suggested "and" statement, "harder to program for, weaker console." So that means you're implying that you believe neither of those will happen. If you worded yourself wrong, then I understand. ;]
What the actual fuck are you talking about?
Seriously, you're babbling and you aren't saying anything that makes sense.
Let me help you out, because I'm tired of your posts.
Uhhh, ok? Let's see where you're trying to go with this.
100% wrong. Let me buy a high end card with DDR3 ram. Oh wait, I can't. You know why? Because you need the "intrinsic" benefit of the high BW that GDDR5 has. And if you want to use the 7770 as an example of low bandwidth you're just playing stupid. The 7770 has a 128 bit interface. You have to have a much higher bit depth (dual or possible quad channel) to achieve those numbers with DDR3. You look at typical BW's for ram on PC and you see maybe 30 or so max for DDR3 and that's at the highest clock rates that are barely supported on mobo's.
Worse for what? Or do you just want to say it's worse. DDR3 is worse. (hurrr). And yes, GDDR5 does have higher BW, which is what matters with VRAM and rendering. DDR3 works wonders for things like the i7 so it can do heavy CPU functions, but not only do we know that APU's are bandwidth starved machines (low latency isn't needed) but we are talking about two very weak CPU's in these consoles... it's not going to make a huge difference.
Individually or combined, you cannot achieve the bandwidths of the GDDR5. You can't, it's impossible. And the low latency won't give you the benefits of the 70 GB/s difference. You might be able to use it for the CPU as CPU tasks are latency sensitive but the eSRAM is on the GPU not the CPU. So instantly you'd increase latency there. Not only that but ANY TIME you increase bandwidth, you increase latency. So the DDR3 in the Durango is going to be MUCH HIGHER than the ones in PC's. It's a fact. That's why low latency high bandwidth memory solutions like embedded memory is super costly and hot.
Gemüsepizza;50337021 said:
If you want to believe that, it's okay too.
Sorry, Microsoft making a hard to program for console just doesn't make any damn sense from past history.
phosphor112
Banned
I guess unless it does move engine stuff near automatically along with accessing their eSRAM accessing... but automatically dealing with hardware is highly inefficient.
So, it's pick your poison... It's like if someone just ran code on the Cell and it automatically separated jobs into the different SPE's... very inefficient.
Gemüsepizza
Member
It makes sense because they wanted 8 GB of RAM for their non-gaming stuff, so at that time they thought it was the only way to achieve it and that it was worth it. The Durango does not seem like a pure gaming console, so it is really not surprising that there are some trade-offs regarding game performance. And that's what the rumors say. You can of course ignore them, but it's pretty laughable to then call out others for "wishful thinking".
It's not that difficult in practice as memory handling is straight forward- only difficult part is keeping everything in the pre defined limitations (as with everything)
And considering the ESRam will have a lot less contention with other fragments of game code it is much much easier to manage (both space and bandwidth wise) than having everything lumped into the main ram pool-don't have hundreds of things going through ESRam... Only specialized tasks
I'm not sure I follow this.
How is this simpler than one pool of memory? With one pool of memory I make an allocation, and that's it, it's in memory, and sans considerations about the cache friendliness of algorithms I'm probably not going to think much further about it.
With two pools of memory I have to think about what should go where, when, and how to schedule data movement between the two, in order to optimise usage (and, from a bandwidth pov, achieve something less than one fatter pipe going to one pool of memory could allow). This requires more programmer sweat equity.
weren't you the one that said you would give every rumor an equal chance , including always online and no used games?
Why disprove these now ?
Remember ANYTHING can happen
For all we know MS has become just as arrogant and insane as sony was at the begining of this gen after seeing the success of the xbox and now believe that as long as the XBOX logo is on the device it will sell millions price and functions be damned.
or are you realy thinking that they are incapable of making a complicated devkit that they sent to devs with the message "deal with it "on it like sony did in the past ?
Sony's fuckup is't an unicum that only happens when the stars align .
ms could very well become "THAT" company this gen .
Galacticos
Banned
Reiko starting to show his true colors.
AgentP
Thinks mods influence posters politics. Promoted to QAnon Editor.
The eSRAM is not about making thing simple, it is about giving the GPU a work ace that is higher bandwidth and not shared with the rest of the system. If your main pool of memory is high enough bandwidth then contention doesn't matter and it is as simple as it gets. The question becomes is a 176GB/s shared going to be higher than 102GB/s dedicated (ignore the size)? I would expect so, I would guess the GPU in Orbis to have ~130+GB/s left over. You can guess the expected GPU bandwidth by looking at the GPU itself and comparing it to the PC parts and their dedicated memory bandwidth.
I don't see how juggling maion RAM, eSRAM, Move engines, etc. is simple - mark my words devs are going to complain.
statham
Member
interesting.I've been posting this stuff over B3D, but AMD has a new part supposedly to be coming in April, the "Bonaire" or 7790 GPU. It's supposed to slot between 7770 and 7850 on PC's.
Notable things about this guy are, it sports 768 SP's. Which is 12 CU's. In other words exactly what Durango is rumored.
http://translate.google.com/transla...radeon-hd-7790-bonaire-i-sweclockers-testlabb
Another thing is, it seems to be possibly clocked at 1075 mhz stock. The link calls it a overclocked model, but every spec sheet I've found claims 7790 is clocked at 1075 period (for example this link http://www.tomshardware.com/news/AMD-Radeon-7790-Saturn-GPU,21447.html ). Additionally a lot of links claim AMD wont allow overclocked 7790 so as not to encroach on 7850. Which would mean they all have to be the same clock.
So if 1075 is stock, I'm really hopeful for a Durango clock bump to at least 1 ghz.
There also seems to be some claims Bonaire is GCN 2.0, which is also interesting. If it's the same as PS4 it probably doesnt mean a lot though. It wouldn't surprise me.
Also another thing pointed out on B3D, 7790 spec sheet lists:
Is exactly the same as the Durango ESRAM BW I think. A little odd/coincidental anyway.
Phonomezer
Banned
No it doesn't. Especially when you consider they're the only manufacturer getting exclusive releases from the makers of CryEngine and Unreal Engine. They would've worked closely with them during the creation of Durango.
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