• Hey, guest user. Hope you're enjoying NeoGAF! Have you considered registering for an account? Come join us and add your take to the daily discourse.

VGLeaks rumor: Durango CPU Overview

ekim

Member
There are lot of differences to the 360 CPU being explained - are all those stock-Jaguar features?

something like this :
Like most recent high-performance x64 processors, the cores do not execute the x64 instruction set natively; instead, internally instructions are decoded into micro-operations, which the processor executes. This translation provides opportunities to parallelize beyond traditional superscalar execution.

Durango CPU cores have dual x64 instruction decoders, so they can decode two instructions per cycle. On average, an x86 instruction is converted to 1.7 micro-operations, and many common x64 instructions are converted to 1 micro-operation. In the right conditions, the processor can simultaneously issue six micro-operations: a load, a store, two ALU, and two vector floating point. The core has corresponding pipelines: two identical 64-bit ALU pipelines, two 128-bit vector float pipelines (one with float multiply, one with float add), one load pipeline, and one store pipeline. A core can retire 2 micro-operations a cycle.
 

Durante

Member
Looks really standard.

The Durango CPU does not support line or way locking in either L1 or L2, and has no L3 cache.
This was one of the rumored modifications. Doesn't look like it's happening.

No FMA either, I thought that might happen after the improved vector units rumor.
 

Durante

Member
There are lot of differences to the 360 CPU being explained - are all those stock-Jaguar features?
Yes, exactly, in every detail, it's the same song and dance we had for the GPU.

Depending on how cynically you chose to interpret it, it's either:
- a good faith effort to educate console developers who may not be familiar with PC architectural trends
- a marketing method to make the system seem more powerful and special, both to developers and particularly in case of leaks
 

monome

Member
hummm...

can MS pull out a Wii, and release Durango at a very affordable price?

the less customization etc, the fastest its components will be cheaper to produce etc...

720 being 100$ less than PS4 and launching globally day 1 are the only things that I'm interested from what I gathered on Durango rumors.
 
Durango CPU cores have dual x64 instruction decoders, so they can decode two instructions per cycle. On average, an x86 instruction is converted to 1.7 micro-operations, and many common x64 instructions are converted to 1 micro-operation. In the right conditions, the processor can simultaneously issue six micro-operations: a load, a store, two ALU, and two vector floating point. The core has corresponding pipelines: two identical 64-bit ALU pipelines, two 128-bit vector float pipelines (one with float multiply, one with float add), one load pipeline, and one store pipeline. A core can retire 2 micro-operations a cycle.

Pretty much exactly like a vanilla Jaguar.

9nbtrj8.jpg
 
Perhaps this is deliberate dissemination of misinformation prior to the unveil in April.

Why? VGLeaks have been bang on the money pretty much all the way through, why ruin that reputation?

It's far more likely that our esteemed "insiders" were being fed misinformation from MS to make Durango seem much stronger than it actually is. A last minute doubling of CPU power via IPC improvements or clock speed always seemed unlikely.
 

Sid

Member
hummm...

can MS pull out a Wii, and release Durango at a very affordable price?

the less customization etc, the fastest its components will be cheaper to produce etc...

720 being 100$ less than PS4 and launching globally day 1 are the only things that I'm interested from what I gathered on Durango rumors.
Anything can happen,I think both of them will be around the same price since the PS4 won't have an advanced camera like Kinect 2.
 

iMax

Member
Why? VGLeaks have been bang on the money pretty much all the way through, why ruin that reputation?

It's far more likely that our esteemed "insiders" were being fed misinformation from MS to make Durango seem much stronger than it actually is. A last minute doubling of CPU power via IPC improvements or clock speed always seemed unlikely.

How do we know this?
 

Reiko

Banned
Why? VGLeaks have been bang on the money pretty much all the way through, why ruin that reputation?

It's far more likely that our esteemed "insiders" were being fed misinformation from MS to make Durango seem much stronger than it actually is. A last minute doubling of CPU power via IPC improvements or clock speed always seemed unlikely.

However, some of VGleaks data is old. The documents did not mention "100% GPU efficiency".
 

KidBeta

Junior Member
How do we know this?

Orbis was correct nearly 100%. Aside from ram amount.


However, some of VGleaks data is old. The documents did not mention "100% GPU efficiency".

Why would it, that wasn't related, it is obviously from the same document.

The information from vgleaks is identical to the information from the document your thinking of anyway :).
 

Durante

Member
It's far more likely that our esteemed "insiders" were being fed misinformation from MS to make Durango seem much stronger than it actually is. A last minute doubling of CPU power via IPC improvements or clock speed always seemed unlikely.
If we're speculating likelihood, I think it's even more likely that the people leaking specs don't understand them. E.g. they read "double-pumped vector unit" and think "oh wow, it's double-pumped, probably twice as fast as stock Jaguar!".
 

DieH@rd

Banned
hummm...

can MS pull out a Wii, and release Durango at a very affordable price?

the less customization etc, the fastest its components will be cheaper to produce etc...

720 being 100$ less than PS4 and launching globally day 1 are the only things that I'm interested from what I gathered on Durango rumors.

Price of the APU will be determined by its size and yields. Even though CPU and GPU seems to have no customizations, APU still hosts 32 MB ESRAM which is made [according to rumors] from staggering 1.5billion transitors [6 transistors per bit].

Durango's APU will be larger than PS4's... and definetley slower.
 

Reiko

Banned
Orbis was correct nearly 100%. Aside from ram amount.




Why would it, that wasn't related, it is obviously from the same document.

The information from vgleaks is identical to the information from the document your thinking of anyway :).

Do you mean this is all coming from the info SuperDaE leaked?

;)
 

Tratorn

Member
VGLeaks informations are from february 2012 iirc. Thats enough time to do other modifications like some rumours said.
 
However, some of VGleaks data is old. The documents did not mention "100% GPU efficiency".

This "100%" is a standard GCN feature and not really worth mentioning. All it means is that AMD are moving away from VLIW style architecture more towards Nvidia's Fermi/Kepler. In the end it makes literally no difference to the actual performance of the chip, just that the real world performance is closer to the theoretical maximum.
 
With PS4 I can't think of anything they got wrong other than the 8GB GGDR5 which seems to have surprised first party developers also.

They also were saying something about 14+4 CU's, which kind of possibly seems to be wrong? Things were so vague though it's hard to say if they were really "wrong".

No doubt for the most part the info was right. It was the same info a few people were already spreading around B3D and neogaf weeks prior.

This "100%" is a standard GCN feature and not really worth mentioning. All it means is that AMD are moving away from VLIW style architecture more towards Nvidia's Fermi/Kepler. In the end it makes literally no difference to the actual performance of the chip, just that the real world performance is closer to the theoretical maximum.

You have no idea if this is true. And if anything, it seems lately Nvidia is moving towards AMD architecture imo. The 100% efficiency thing is in reference to a confidential Microsoft Durango slide that some people have access too, it is likely not a generic GCN "feature", and likely applies to the Durango GPU as a whole including ESRAM.

I've heard a reason Nvidia cards get more performance per flop is lower latency caches than AMD, and ESRAM could fill something like that role for Durango.
 

Durante

Member
Anything can happen,I think both of them will be around the same price since the PS4 won't have an advanced camera like Kinect 2.
I think PS4 will be much more expensive since it won't force you into a 2 year contract to go with it.
 

Biggzy

Member
Price of the APU will be determined by its size and yields. Even though CPU and GPU seems to have no customizations, APU still hosts 32 MB ESRAM which is made [according to rumors] from staggering 1.5billion transitors [6 transistors per bit].

Durango's APU will be larger than PS4's... and definetley slower.

They seem like they will be virtually the same size.
 

Reiko

Banned
This "100%" is a standard GCN feature and not really worth mentioning. All it means is that AMD are moving away from VLIW style architecture more towards Nvidia's Fermi/Kepler. In the end it makes literally no difference to the actual performance of the chip, just that the real world performance is closer to the theoretical maximum.

While that's a standard feature, that's actually a good thing for both consoles. So yes, better efficiency is worth mentioning.
 

i-Lo

Member
Why? VGLeaks have been bang on the money pretty much all the way through, why ruin that reputation?

It's far more likely that our esteemed "insiders" were being fed misinformation from MS to make Durango seem much stronger than it actually is. A last minute doubling of CPU power via IPC improvements or clock speed always seemed unlikely.

I should clarify I didn't mean vgleaks, rather MS, in terms of the information being out of date. But you're correct on vgleaks has been mostly on the money pertaining to previous leaks.
 
If we're speculating likelihood, I think it's even more likely that the people leaking specs don't understand them. E.g. they read "double-pumped vector unit" and think "oh wow, it's double-pumped, probably twice as fast as stock Jaguar!".

Yes, that has been my theory from the beginning. The same way the color and Z compression was misinterpreted, the way improved efficiency was misinterpreted, even the way DMEs were misinterpreted. I'm sure in one of these threads I suggested the exact same explanation as you just did for where the "Durango CPU is 200GFLOPs" rumor came from.

Of course, it doesn't help that when AMD says "double pumped" they mean "it takes 2 cycles" and when Intel says it they mean "it runs at double the clockspeed".
 

Tomcat

Member
all those thinking that these consoles will be inexpensive should be ready for a reality check. Thurrott said that their prices will be high. The number 6 was mentioned :p
 
Price of the APU will be determined by its size and yields. Even though CPU and GPU seems to have no customizations, APU still hosts 32 MB ESRAM which is made [according to rumors] from staggering 1.5billion transitors [6 transistors per bit].

Durango's APU will be larger than PS4's... and definetley slower.


No, the 6T per cell is for SRAM. Durango will use ESRAM which is just edram. Same as WiiU
 

KidBeta

Junior Member
VGLeaks informations are from february 2012 iirc. Thats enough time to do other modifications like some rumours said.

I do not think they have enough time they want to release this year.

They have to get the beta dev kits out do not forget.

They had dev kits ~ month ago no?.

They would have been near final.

They would have to have time to be produced.
 
While that's a standard feature, that's actually a good thing for both consoles. So yes, better efficiency is worth mentioning.

But it's only more efficient because the theoretical maximum is much lower. Put it this way, using AMD's old architecture the theoretical max FLOPs of chip X sat at around 4.5TF, the real world performance was 1.5TF (efficiency of 33%), on the new architecture, the theoretical maximum is just 1.5TF which is now matched by real world performance because of architectural changes, however it's basically the same as before. All AMD did was bring their max performance down from ridiculous levels under VLIW to more realistic levels for GCN. Basically aping Nvidia.
 

Reiko

Banned
But it's only more efficient because the theoretical maximum is much lower. Put it this way, using AMD's old architecture the theoretical max FLOPs of chip X sat at around 4.5TF, the real world performance was 1.5TF (efficiency of 33%), on the new architecture, the theoretical maximum is just 1.5TF which is now matched by real world performance because of architectural changes, however it's basically the same as before. All AMD did was bring their max performance down from ridiculous levels under VLIW to more realistic levels for GCN. Basically aping Nvidia.

Ah.
 
all those thinking that these consoles will be inexpensive should be ready for a reality check. Thurrott said that their prices will be high. The number 6 was nentioned :p

Umm, no. I think Sony already said 599 is out. Tho I think with 8GB of GDDR5 a high end SKU of 499 is likely for PS4. Likekly then also a 399 SKU, which might not be too gimped since all models should include a hard drive (then again, I'm worried with Blu Ray Standard, games will average more like 25-50GB's which will eat HDD space fast)

It's worth keeping in mind both Durango and Orbis should be closer to 300mm of silicon vs 500mm in 360/ps3 at launch. Keep that in mind, the price could be quite managable. ESPECIALLY for Durango imo, where you're looking at dirt cheap RAM (really dirt cheap) on top of only 300mm of silicon.
 
Top Bottom