Microsoft Xbox Reveal Event - May 21, 2013

[sebbbi]

I thought Rage's megatextures were a kind of PRT implementation?

Yes, but Rage has a pure software virtual texture implementation. We have a similar software virtual texture implementation also in Trials Evolution (x360 game). Hardware PRT is more efficient than software implementation (and also more easy to utilize efficiently, because you don't need huge indirection textures to have large enough address space). Just like Carmack, I have been waiting to get this feature to the hardware. And it seems that it's finally becoming true

 

[lowlyMonk]

General consensus is 6T eSRAM.

Can you source how 32mb of 6T eSRAM = 1.2 billion transistors?

 

[MrFox]

Do we know this? or is this just an assumption? i missed the start of the tech panel.

From the wired link that others have posted above... there's a shot of the motherboard and it has 16 chips. 8GB was confirmed, so they are 4Gb.
http://www.wired.com/gadgetlab/2013/05/xbox-one/

 

[anexanhume]

Can you source how 32mb of 6T eSRAM = 1.2 billion transistors?

32,000,000 x 8 x 6 = 1.536b actually.

 

[(((interference)))]

I think that's the point. If you are making a play for the living room then it helps if you make it as similar as possible to other A/V components that you normally see an A/V cabinet.

Yes, but it doesn't have to be boring - the 360S design was much more interesting and still looked like a premium device (and one that should be mistaken for your set top box/DVR/Bluray player etc)

Sony's PS4 design looks like it'll be more interesting from the few glimpses we've seen.

 

[McHuj]

Can you source how 32mb of 6T eSRAM = 1.2 billion transistors?

~1.6B= 6 Transistors * 32 MB * (1024*1024) Byte/MByte * 8 bits/Byte

 

[Strange]

Can you source how 32mb of 6T eSRAM = 1.2 billion transistors?

32MByte * 1024KByte/MByte *1024 Byte/KByte * 8bits/Byte * 6T/bit = 1,610,612,736 Transistors for the eSRAM itself.

1.6 billion, I never said 1.2 billion.

 

[expletive]

Just listened again. He definitely said over 200GB/s in the memory subsystem, fwiw. The 2Gb/s was for Kinect data transfer.

 

[dragonelite]

Can you source how 32mb of 6T eSRAM = 1.2 billion transistors?

6 transistors per bit.
6 * 8 * 1024 * 1024 * 32 = 1.6 billion

 

[blakjedi]

Getting back to what I saw when I was pointed to partially resident textures, I came across the AMD presentation from GDC 2012 which showed that capability that became available in hardware in the 7970.

https://www.google.com/search?q=partially+resident+textures

second link from the top.

I am NOT stating that there's a 7970 in the xbox one.

 

[Proelite]

Not's not forget the total system bandwidth of the 360 according to Major Nelson.

 

[AstoundingHolmes]

Is it my imagination or are the buttons extremely shallow?

 

[MrFox]

6 transistors per bit.
6 * 8 * 1024 * 1024 * 32 = 1.6 billion

and that's just for the cells, from what I understand, there's a big additional overhead to make a complete array and interface it.
there's also a defect management necessary.

 

[Cjail]

Sorry if I say this but I think they are "adding" bandwidth there.
They are not giving individual bandwidth figures for CPU, GPU or memory type.

 

[shiznit]

Only way the specs make sense is if they plan on eventually moving the eDRAM off die to stacked memory to save costs, if that even saves any money. Otherwise the PS4 design is a much better use of the transistor budget.

Not really sure what they were thinking.

 

[Wynix]

Just listened again. He definitely said over 200GB/s in the memory subsystem, fwiw. The 2Gb/s was for Kinect data transfer.

6 transistors per bit.
6 * 8 * 1024 * 1024 * 32 = 1.6 billion

So 64MB eSRAM?

 

[expletive]

Not's not forget the total system bandwidth of the 360 according to Major Nelson.

This guy is talking about operations per clock in one breath, and then memory subsystem bandwidth in the next. This is not Majornelson.

Sorry if I say this but I think they are "adding" bandwidth there.
They are not giving individual figures for CPU, GPU or memory type.

Obviously but it still leaves roughly 40GB/s unaccounted for from what we know.

 

[blakjedi]

they had to have included the transistor budget of what is in the Kinect in that 5bn number.

 

[GrimThorne]

Interesting, the Wired article is also claiming Xbox One with both 1080p and 4K supported.

 

[bkilian]

Just listened again. He definitely said over 200GB/s in the memory subsystem, fwiw. The 2Gb/s was for Kinect data transfer.

maybe they doubled the ESRAM to 64 MB? That would take care of the "missing transistors" and the memory bandwidth.