Curious question, what is the point in disabling portions of hardware? Is it for heat/power consumption reasons? What is the point of having them at all? Can they be software unlocked or is it hardware based?

itBourne:

It's because of production yields (how many chips of a batch are actually working).

When making the chips, a lot of things can go wrong. Sometimes it's just a single part of a chip that doesn't work right.

In the PS4's case, there are 20 compute units (CU) on-die vs. the 18 CU's available for the developers to use.

This is done because if any 2 of the 20 CU's are tested as faulty, but the rest of the chip works perfectly, they will simply be disabled, and the remaining 18 are the fixed number, that developers have access to.

Even if a chip is 100% perfect, with 20 working CU's, two will still be disabled.

This is because the developers needs to know exactly what hardware is in the console, so it's no use for them if 10% of the PS4 consoles has 20 working CU's, 25% has 19 working CU's, and 65% has 18.

They need to code for the lowest denominator, in this case 18 CU's.

Every complicated chip has redundant parts, for better yields.

@itBourne:

Also piggybacking on what Fangrim said, since developers develop for 18 cores, the 2 extra cores can be turned on to provide extra power. I would imagine, this is a defined "list" by Sony in the form of silent updates. So, if you have 20 functional cores, and a game runs lower than desired spec, say 50 fps, Sony can define a list of games in which the two extra cores activate.

So, in the worst case scenario where you have a working system, the game runs perfectly as the developer intended. I'd imagine this feature is not available yet though.

If one takes an HD7870, removes two of the 20 compute units, then down-clock the chip from 1ghz to 800mhz, you get 1.8 tflops, which is pretty much on par with what Sony has advertised.

But... after giving that image a thorough looking over, I'm not counting enough Texture Units. It should have 80 with a portion of them disabled.

"But... after giving that image a thorough looking over, I'm not counting enough Texture Units. It should have 80 with a portion of them disabled."

It's 72 for PS4, 48 for XBOX ONE.

PS4 has essentially a Radeon 7870ghz, with lower clocks (800mhz) and 2 CUs disabled, meaning 1152 shaders, 72 TMUS and 32 ROPs. It also has modifications to its compute performance.

It is most likely ever so slightly faster than a Radeon 7850.

Xbox One has a 7790, but with lower clocks (853mhz), and 2CUs disabled.

This means 768 shaders, 48 TMUs, and 16 ROPS.

It is about as fast as a Radeon 7770.

7850 v 7770.

Its a pretty large gap.

Basically speaking yes.

Technically speaking no.

Wii U = AMD 4000 series GPU
5000 series
6000 series
7000 series
PS4 = AMD R9 270

Kinda funny someone bothers to make a comment and cannot spell extremetech. /s

@jack_of_all

I dont see how that is relevant at all, Maybe if it was a website telling ppl how to write sentences and it was filled with false info, them i call them out on it but spell by own words wrong then yes maybe , but no this is a website with tech in their name talking about system architecture and they are getting things that are obvious wrong.

Kind of* funny that/how* someone bothers to make a comment,* and cannot spell "extremetech"*.

Please. Don't go grammar nazi over typos. Unless the /s means it was a joke.

I kind of get the point they're making, that in terms of raw power the CPU and GPU are normally 50/50 but for this gen the GPU is massively more powerful than the CPU - this is what they mean when they say it's similar to the Wii U and in that respect, they're correct - but that's pretty much the ONLY similarity.

No, sir. My name is Hickok. Bill Hickok.

It's worse than that, a stock 7870 is 20 CU's, 2.56TFLOP/s at 1GHz. PS4's GPU however, has been cut down to 18 CU's, 1.843TFLOP/s at 800MHz.

XBOX ONE's situation is actually even worse as MS devs confirmed the same situation.

A stock 7790 is 14 CU's, 1.792TFLOP/s at 1GHz, XBOX ONE's GPU has been cut down to 12 CU's, 1.310TFLOP/s at 853MHz.

@Beast a 7870 is a middle range card between £130-£200 so even if its downgraded its not a shit. Oh and cos ts apart the 7000 series (R series) there great at being overclocked.

Its not that easy to spend a little more.

See, everything is on one die. You are limited to how large you can really build a processor by the technological limitations of the manufacturing process.

Because PS4 and Xbox One both pack everything onto a single die, CPU, GPU, memory controllers etc, the die is now pretty huge.

A Radeon 7870 die BY ITSELF for example is only 212mm squared with about 2.8 billion transistors.

PS4 and Xbox One's dies are about 350mm squared with around 5 billion transistors. The maximum transistor budget here was about 5bn transistors.

Its about the size of a Radeon 7970 (R9 280) which is still a fairly high end graphics card.

In order to make the GPU much more powerful and have the redundancy for yields they currently have (disabling 2 CUs) then the die size would begin to get out of control, making it vastly more difficult and more expensive to manufacture.

Which makes it cost a lot, lot, lot more.

If you wanted a (7970ghz) R9 280X on there, in addition to the CPU and everything else, the die would easily be 450mm+ squared. You have the size of the GPU which is as we know is about 365mm squared, and then everything else on top.

An R9 290 has over 6 billion transistors, on a die 438mm squared. They cost about £300/$400.

A much larger die than what the consoles have now is impractical in cost and manufacturing and heat terms. You're talking about a die larger and more expensive to produce than an R9 290!!!!

The only usable solution would be to have separate chips, a separate CPU and GPU which again only increases cost, manufacturing, assembly, cooling, complexity etc.

They were determined to keep costs down as much as possible which is why they both went for APUs, and thus limited by that technology.

Its like the final episode of the Sapranos. You gonna go to make a comment and when you click add th-

Timezone thing maybe.... RIP

I thought the more common complaint about Uncharted franchise was how the main cast are the good guys acting so nonchalantly while killing hundreds in cold blood (aka the dissonance between gameplay and story cutscenes). They just did it again in Part II.

Sorry just had to say this lol! RICKYYYY!

Man Cuba Gooding Jr was miscast in that movie, but that part was cringey it was sad and funny at the same time man.