Consoles Vs PC bandwdith

[pjbliverpool]

Im calling complete BS on this one. Yes HSA is going to have its advantages but 1) its nothing you cant get around on the pc given enough raw power or enough engine scaling and 2) since when did ea ever push the limits in anything? The real reason for this is that pc gamers dont really care for that yearly recycled shite so ea thought they'd cut their losses in that segment and massage the console gamers balls at the same time by claiming its for performance reasons. Meanwhile you'll have crytek or similar releasing cysis 4 or similar in a year or two that craps all over EA's best and runs on midrange level pcs just fine.

Sorry for being blunt.

 

[blakjedi]

Question: what are the real constraints of bandwidth? Does the CPU have set maximum instruction limit? Two instructions per cycle per thread times 1.6ghz. Outside of gpgpu that represents the theoretical maximum of instructions that could be made available to the gpu?

At 100 percent efficiency does that number easily saturate the bandwidth? To me it seems that the CPU is what will hold back the PS4 if anything.

 

[Shifty Geezer]

1.6 billion 4 byte SP floats = 6.4 GB/s per op. Googling, one core performs 4 SP FMADDS, so 25.6 GB/s peak per core. 8 Cores means 205 GB/s peak theoretical data consumption via the CPU for floating point calcs alone.

Although I think I misunderstand what you're asking.

 

[Rangers]

Im calling complete BS on this one. Yes HSA is going to have its advantages but 1) its nothing you cant get around on the pc given enough raw power or enough engine scaling and 2) since when did ea ever push the limits in anything? The real reason for this is that pc gamers dont really care for that yearly recycled shite so ea thought they'd cut their losses in that segment and massage the console gamers balls at the same time by claiming its for performance reasons. Meanwhile you'll have crytek or similar releasing cysis 4 or similar in a year or two that craps all over EA's best and runs on midrange level pcs just fine.

Sorry for being blunt.

yeah. it's pretty obvious just an excuse and the real reason is "they dont sell that well on PC".

PC seems an odd place for sports games anyway, as like most genres they work way better on a controller.

 

[joker454]

If pc power was the limiting factor then why did so many companies, including EA with their own game Battlefield, showcase their wares at the show on pc's? EA had a monstrous pc setup right when you walked into the main e3 hall, why purposely bottleneck their games when they could have just run them on ps4's?

 

[blakjedi]

1.6 billion 4 byte SP floats = 6.4 GB/s per op. Googling, one core performs 4 SP FMADDS, so 25.6 GB/s peak per core. 8 Cores means 205 GB/s peak theoretical data consumption via the CPU for floating point calcs alone.

Although I think I misunderstand what you're asking.

No. You old geezer. That's exactly what I was looking for... I missed the 4madds... So it messed up my calculations. Ok so the CPU will not be the limiting factor... Efficiency will. Without that multiplier I wasn't getting 205. Thank you sir. So both systems are actually bandwidth starved... Wow

 

[Shifty Geezer]

In principle, but that's true for the GPU too. A GPU can consume terabytes per second of information if you were to feed the ALU's 100% of the time working on new data in (and data out, which I didn't factor into my BW calculations. You need to write the data out to RAM, so that's potentially twice as much peak BW needed). The BW for feeding the ALUs comes from the cache, and that's the whole issue of the memory system within a computing architecture - balancing fast, local stores with cheap, slow stores and massive, slothful permanent storage. This is also why peak FLOPS and OPS and MIPS numbers get pretty meaningless, and it's actual achieved, sustained performance that really matters.

 

[blakjedi]

I see. So in terms of directional capability you would just halve the bandwidth in the ps4 to figure out how much is available at any moment for read/write operations. Understanding that I get how advantageous the ps4's full cpu/gpu to RAM bandwidth number is.