Technical Comparison Sony PS4 and Microsoft Xbox

So the PS4 requirements for OS will come out of thin air ?

 

Yeah, but since when was a 2GB OS reservation considered low for a games console?

Look how much the iPhone 5 can do with only 1GB, surely double that would be enough for whatever Sony wanted to do.

Having 3GB reserved seems quite unnecessary - if it is indeed true.

 

interesting interview on next gen consoles with 4A developer !

 

TBH i doubt many games will use MSAA, the general direction is post processing like FXAA or SMAA, i think especially SMAA is pretty good und needs far less perfomance.

I agree, i would be shocked, if the PS4 doesnt reserve some GPU time for the OS.

Nobody is arguing that the GPU in the PS4 isnt better, but i very much doubt you will see multi games that run 30 FPS on X1 and 60 FPS on PS4 (sebbi explained why); i think the main difference will be in resolution (pixel and texture).
Exclusive games is a different matter, i think Naughty Dog will simply "crush" everyone next gen

 

This is true, do we know anything about the performance of the given ROPs on given formats?, this might be a reason for them picking a high number if some run at 1/2 or even 1/4 speed and are common then it would be worthwhile no?.

 

Radeon 7770 GE vs 7850 benchmarks. Ok, lets compare the benchmark results with the card specifications.

ALU (GFLOP/s): 1280 vs 1761.28 (+38%)
Bandwidth (GB/s): 72 vs 153.6 (+113%)
Fillrate (GP/s): 16 vs 27.52 (+72%)
Texture sampling (GT/s): 40 vs 55.04 (+38%)

Actual performance in Anandtech benchmark (all games):
- Average: 1070/1689 = 1.58 (+58%)
- Minimum gain (Battlefield): 61.2/43.3 = 1.41 (+41%)
- Maximum gain (Batman): 62/36 = 1.72 (+72%)

Performance gain is limited by each game's/engine's bottlenecks. Battlefield seems to be mostly ALU or TEX bound (or both). Thus it only gains slightly more than the 38%. It represents a modern game engine. Older games/engines tend to be more fill rate bound (simple pixel shaders with less ALU/TEX instructions). Thus Batman's performance gain (+72%) is identical to the raw fillrate improvement from 7770 -> 7850. To support that extra fillrate and extra TEX you of course need extra bandwidth. That +113% BW improvement is enough to feed the +38% TEX and +72% fill capabilities of 7850.

Unfortunately we do not have any official ROP or TMU information about the consoles, and neither any ALU (FLOP/s) information for Xbox One. The only official information we have is the bandwidth figures: 200+ GB/s for Xbox One (XBox One reveal tech panel) and 176 GB/s for PS4 (Sony's PS4 press release). It's too early to draw any conclusions about that information, except that memory bandwidths of those devices are quite similar. And that's good since memory bandwidth is one of the most important thing for GPU compute (future engine graphics pipelines are also mostly compute based).

 

I'll be cheeky and do this then. Making an assumption that both GPU's are clocked at 800MHz. XBox One & PS4. Based on best available information.

FLOPS 1200 / 1840 (+53%)
ALU (GFLOP/s): 1200 vs 1840 (+53%)
Bandwidth (GB/s): 170 vs 176 (+3%)
Fillrate (GP/s): 12.8 vs 25.6 (+100%)
Texture sampling (GT/s): 32 vs 51.2 (+60%)

That will give me worst return of around 55% and a best of 100%, dependent upon what the game engine is limited by?

 

Improved fill rate and texture sampling rate needs extra bandwidth in addition to ROPs and TMUs. Otherwise it's going to become bandwidth limited. If you compare Radeon 7770 -> 7850, there's +113% extra bandwidth to feed that +72% fill rate and +38% texture sampling rate.

In your chart the worst case return is %3 (bandwidth). This occurs if the engine is already bandwidth bound.

 

Thanks for the intelligent breakdown sebbi.
Won't the ps4 have much more general bandwidth though to fill those rops? Durango only has 32mb sram to play with, is it really a fair comparison to say ps4 has only 3gb/s bandwidth advantage? In most cases wouldn't liverpool soc have much more wriggle room?

 

Go to Vgleaks, copy between ESRAM and DDR 3 are not free. Xbone has more than 6 GB/s deficit in memory bandwidth...

 

This probably further solidifies 3Gb RAM reserved on Ps4 likely. He obviously just cant day it cause of NDA so he talks around it like that.

 

That's a bit of a stretch ....

 

Still, given their transistor budget going with ESRAM to support DDR3 kind of blew away most of their options. Cost wise I don't know how that compares to PS4 though. Given what we know, would the overall SoC cost more than PS4's? Is the total BoM even that much lower than PS4's? Minus Kinect.

 

The transistor count is a bit misleading because it's not necessarily proportional to the die area. An SRAM array is extremely dense compared everything else. I wouldn't be surprised if both SoC end up just a bit above 300mm2. So about the same cost.

Savings for using DDR3 instead of GDDR5 could be more than enough to counterbalance the additional cost of Kinect2 versus the PSEyes. Both consoles could have a very close BOM, depending on what Sony decides to bundle.

 

No it doesn't if fact it says nothing other then he expects them to use a non infitessimile portion of it for the OS. 2GB's which i think is probably the local spot for Sony to end up is still 25% of the overall ram which is not a small amount.

 

I still understand why any console would need such a huge amount of memory for the OS...

They need remember what these things were built for..GAMES...

Ditch the bloated OS and give the extra RAM and processing power to the developers to improve the GAMES...

 

There is enough RAM even with the bloated OS. If these were the simle game boxes of old, they likely would not feel it necessary to stick 8GB in there.

 

Also, given that each Xbox One will come with a HDD standard, wouldn't it be possible to just stream in asset if the RAM has been used up? 5gb of RAM is a lot but I would imagine that a mixture of RAM access and streaming in assets should do.

 

I have been thinking the same

PC games must work perfectly with just 2 GB of system memory + 1 GB of graphics memory. Windows XP is still widely used, and there is a 32 bit version of Windows Vista, 7 and 8. You can't just drop support for all of these operating systems. Also most players are using a 1080p display, but 70% of the players (according to Steam Survey) have 1 GB of less graphics memory. PC games must support 1080p flawlessly on graphics cards that have only 1 GB of memory.

Bottom line: A PC game must work perfectly with just 3 GB of memory (total). All current PC games do so. A 2+ GB graphics card is only needed for super high resolution gaming (2560x1440+), and less than one percent of gamers have monitors like that.