Carmack happy with PS4 system specs

@rarson @Devils-DIVISION  This is more of an article than that of the article this belongs to hah.

@Devils-DIVISION

AMD's blog seems to confirm that the PS4 is using a semi-custom APU, but it's not really clear whether they mean that it's using an APU + GPU, nor is it clear that the near-2 TFLOPS is total power or what. I guess we'll just have to wait for final specs.

@rarson

I see. That's pretty interesting. 

I can't wait to see the full specs-sheet in the near future. Hope I find you in a similar setting, so I can through you some more brainteasers.

Cheers!

@Devils-DIVISION

Well, packaging, price, and in AMD's case, a heterogeneous architecture. By 2014 or so, we should see them releasing chips that can do CPU and GPU instructions automatically, fully heterogenous. They won't be separate components anymore. This will really help push GPGPU compute, which in turn means that more software will take advantage of the processing power provided. I'm sure you'll still have dedicated GPU cards, but it won't be necessary to buy one to get good GPU performance (as it is, the current AMD APUs have pretty decent GPU performance anyway).

I said that Sony's not using an APU, but I'm basing that off the reports that they are using a "CPU." If you don't know, "Jaguar" is the core architecture that is replacing the "Bobcat" cores in Brazos 2.0, the low-power chips AMD is currently using in smaller devices, laptops, and a few desktops. Brazos is an APU design, and Jaguar is meant to be used in APUs as well (Kabini and Temash).

My point in mentioning it is that Jaguar is not slated to be put into anything that ISN'T an APU, and the initial reports when Sony decided to go with an x86 architecture is that they were planning on using an APU along with a discrete GPU chip. I would imagine that aside from a few console-specific optimizations, whatever AMD is providing Sony is going to be largely based off the products that were already in the pipeline. Hence, it would not surprise me if the Jaguar-based "CPU" in the PS4 is actually an APU. I can think of a couple reasons why Sony would report it as a CPU, primarily because that's the term that most people are familiar with. Sony was also rumored to be working on some kind of APU-GPU synchronization technology with AMD similar to, but different from, Hybrid Crossfire (which would marry the GPU power of the APU with the power of the GPU, for even more performance).

In other words, if those initial rumors were correct, and Sony just hasn't elaborated on the full specs yet, it could have even more GPU power than we're expecting, and a pretty interesting APU/GPU architecture that could show a lot of potential. I have no doubt that Jaguar will be robust, but it's interesting to see how Sony has stepped away from making the CPU the central, powerful center of the console and is going with something far more GPU-based. That, along with the choice to use 8GB of fast GDDR5 instead of regular DRAM, is a really good choice that I think will offer an excellent tradeoff between performance and cost. The move to x86 also means it's going to be MUCH more developer-friendly, which is great.

@rarson

Gotcha! Thank for taking the time to correct me.

If the lack of a dedicated/unique GPU decreases shader counts, what real benefit does that faster communication provide with an APU setup?

@Devils-DIVISION 

You're still confused. An APU is a CPU with the GPU on the same die. It's not on the motherboard anymore, it's moved directly onto the same die as the CPU.

There's no physical difference between a GPU that is located on a graphics card versus one that is located on a motherboard (other than PC motherboards with integrated graphics tend to use system RAM instead of graphics RAM for the GPU). All console GPUs are located on the motherboard (that is, they were until the Xbox 360 die shrink that moved the GPU onto the CPU); the reason that it's on the motherboard is because the GPU is fixed hardware and not designed to be replaced. The only thing the card does is make upgrades easier by making the construction modular.

There is, however, a big difference between putting a GPU on die, versus on a card. Having the two on the same die enables them to communicate faster, but it also creates packaging limitations. You're physically limited by size and thermally by TDP. For this reason, shader counts tend to be lower on APUs than, say, a mid-range graphics card. But every console GPU ever has been "on-board" in the same way, so I'm not sure what your concern is. It is no more or less on-board than any other console GPU.

@naryanrobinson @putonekas17 You telling me that the RSX from 2006 with it's "1.6TFLOPS" has almost the same exact processing power as a HD7850 from 2012 with 1.7TFlops? The RSX does not perform any better than a absolete 7800GTX, let alone to a 660GTX. Keep dreaming

@rarson If it is indeed an APU, then perhaps they incorporated an HD 7870M-7970M, underclocked with low TDP? 

@Eldeorn From what i've read, the RSX is based on the G70-71 chip, equivalent performance to a 7800GTX, which has around 400 GFlops SP. The Cell is rated around 200 GFlops. That 1.8TFlops is PR bs for sure. I agree, the ps3 real compute performance should be around 400-700 GFlops. My HD4870 has 1.2 TFlops SP and was realeased in 2008...

http://blogs.amd.com/fusion/2013/02/21/amd/

AMD's blog says it's an APU, but it's pretty ambiguous about what they mean. It does seem to indicate that "near 2 TFLOPS" is the total system power. I guess we'll just have to wait for the full specs.

@naryanrobinson

I have my doubts. For starters, we don't really know much about the CPU. In fact, Jaguar is slated for APU use only, so it's entirely possible that Sony is using an APU and simply calling it a CPU to either hide an ace up their sleeve or for simplicity's sake. It was rumored back when the x86 switch leaked that Sony was using an APU and something akin to Hybrid Crossfire (but different). Assuming it does use an APU (an 8-core, no less), then it's certainly possible the machine could have over 2 TFLOPS of processing power.

I just find it a little unlikely that they'd use Jaguar cores if they weren't going to go with an APU. Not that Sony can't afford it, but I doubt AMD would go back and redesign something as a CPU that was never meant to be in the first place, and the benefits of having a heterogeneous architecture are obvious. I hope they are using an APU, because that would make the machine even more interesting from a tech standpoint.

@putonekas17 Care to back that up with any *actual* facts?

@putonekas17 @naryanrobinson @Eldeorn If you mean based on that it's target is 1080p 60hz, then it requires 4x the power indeed (pixel fillrate and pixel shader operations)?

I've been digging through more material on the net, and while its quite easy to find specs on the PS3 (wikipedia), there is very little on the actual PS4 chip. 

According to swedish wikipedia (most likely based on rumors from devkits), the PS4 GPU has 1.84 TFlops. 

According to Sony, the PS3 RSX has 1.8 TFlops and a total of 2.1 TFlops with the cell included. People question this however, since in real-world applications, it would meassure at around 400-1000GFlops on the GPU.

@naryanrobinson @Eldeorn You're wrong, the PS4's GPU has 4 times more computing power than the PS3's RSX.

@naryanrobinson @Eldeorn Yeah, I stand corrected after looking over some spec papers out there. The GPU mainly differs with the updated feature set it has, which could be considered as "more powerful" even if it's not actually faster - some operations it does is either simpler or more efficient. The ability to flush more data from a faster RAM is ofcourse what really makes it more powerful.

On a different topic i might add

@jeffrobin Have to agree - the actual shooter part of the gameplay was really fun. AI was unpredictable, weapons had a nice feel to them and they all were fun and useful.

One thing that sucked though was the way-too-short and non-epic ending. You collected all these toys and explored every little thing, and then it suddenly was over just like that. The last 1/3rd of the game should have been harder, and three times as long, to make it feel just about right. IMO.

Another thing was the user interface mouse cursor. When you lowered sensetivity for mouse look, it affected the mouse cursor too for some stupid reason, and made it nearly unusable. That, I hated most of all.

@Thanatos2k @Eldeorn @edant79 It was a good game with great graphics for a console and awesome level design. Check out each environment in that game so different, very impressive. It's only problem was it's length and fetch quests. If Id had made it under 10 hours without so much of the get the fandoogle for the conflibralator it would have been much better.

Sucked though? Why?

@Eldeorn @edant79 @Thanatos2k Rage sucked though.  That's the actual problem.