| ShinmenTakezo said: http://www.gamasutra.com/view/feature/191007/inside_the_playstation_4_with_mark_.php This article is from April. Me, and many others on here it seems listened to Mark Cerny when he spoke. He addresses using edram would have been a complication and a UNIFIED MEMORY SYSTEM is better. That statement he makes tells you that you cannot have hUMA with an edram chip on die. Then there is the fact that AMD confirms this. Then you do a little research on what hUMA is and what it means. Finally you mix in a little logic, and wa-la. Your tons of evidence comes soley from MS and one "retracted" statement from AMD. Do some research and stop repeating things MS talking heads have been saying. These guys have been lying through their teeth since the reveal, yet you take their word like it's the gospel. |
He said it was a complication, not impossible. A complication means there is a hill to climb, not an impassible wall.
If you look at the memory diagram that I posted, you could have the DDR memory operating under hUMA and not include the ESRAM. This would mean the GPU would need to copy any data to the ESRAM or back to the DDR RAM. Not a big deal, because the ESRAM is reserved for the GPU anyway. The DDR memory would be unified and accessible to both the CPU and GPU. Or you could have the hUMA operating on the DDR memory and the ESRAM as two separate memory sets. The CPU and GPU would still need to copy memory to the ESRAM but the they would be able to access both the ESRAM and the DDR memory and address the same memory space. The only difference is that the ESRAM would be reserved for graphics only.
And again. Microsoft's developer documentation and during the Architectural Panel held during the reveal, Microsoft has said they're using coherent (heterogeneous) memory. This was confirmed by VGLeaks, this was also confirmed today by XboxOneDev on Reddit (who has been confirmed previously as an Xbox One Developer by the moderators) and lastly it was confirmed by Microsoft back in May during the Architectural Panel by the Distinguished Engineer Console Architect Nick Baker.
"We have to invest a lot in coherency throughout the chip. So there's been I/O coherency for a while but we really wanted to get the software out of the mode of managing the caches and put in hardware coherency for the first time on a mass scale in the living room on the GPU."
http://youtu.be/tLBVHZokt1Q?t=22m (Note this is set to the specific time frame that the quote is from.)
http://en.wikipedia.org/wiki/Cache_coherence
And because you don't believe me, here is ARS Technica's article on it:
http://arstechnica.com/gaming/2013/05/microsoft-talks-about-xbox-ones-internals-while-disclosing-nothing/
At the end of the day, which this definitely is, the bottom line is that the PS4 is where it was yesterday. It features hUMA. The Xbox One also features it, however to what extent, we don't know. But it is there. At the end of the day you are wrong on whether or not the Xbox One features heterogeneous unified memory architecture. It does.
