We've already covered the BC story in a XB360 vs PS3 BC thread. Is there any real reason for everyone to regurgitate the same POVs again?
GamePro Hands-on with 360: Halo 1/2 confirmed BC
- Thread starter dukmahsik
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PARANOiA said:
Well supposedly, they intend to work on the PS4 GPU together, though we'll see what actually happens there down the line. Still if so, at least we could be assured of something more of an exotic custom design come ~2011 rather than the G70 re-working. Of course they may go the straight 'adaptation' route again as well, who knows.
mckmas8808
Legend
Inane_Dork said:
Huh? Care to explain and little more.
london-boy said:
Agreed, but this isn't the case: The PS1 GPU isn't in PS2, which is why Qroach is quite obviously wrong.
Qroach said:
more complicated is purely relative - besides, since you fail to know exactly what's in the hardware in the first place, I doubt you're in a position to make any claims how complicated it is. We already had a thread on backwards-compatibility in which different possibilities were discussed. We pretty much know there's going to be some sort of PS2 hardware inside PS3 to help backwards-compatibility - without knowing what it is, there's really not much more beyond the previous speculation to discuss about. Obviously, I am trusting Sony's marketing division when they state "backwards-compatible with 13'000 titles" and assume that they'll obviously hit their target when they state so. The burdon on the proof is on them once launch day is here, but until they launch, the burdon of proof is on you to state explicitely why you think they'll fail on their target. No one is talking about if it's going to be challenging - of course it'll be - and putting words into my mouth obviously won't help your argument gain credibility either.
Question to you Qroach: Have you ever written an emulator?
Phil said:
But it's unarguable that the PS2's GS is basically the PS1 GPU. Just lots of them in one single chip. With things added obviously. That's a very very simplified explanation, but the point is that the architectures are so similar that emulation there would be trivial.
PS3 is *completely* different from PS2.
Unless the GPU in PS3 has something of a GS on it, or GS compatible behaviour. It's too early to state for a fact PS3 is *completely* different from PS2 until we know what the hardware BC support is.
London-Boy, I suggest you read up on what exactly the Graphics Synthesizer is and how it differs from the PSone's GPU. To address your other point: What if Sony's puts the full EE into PS3 and they only have to emulate the GS? Given this scenario, it wouldn't be that drastic different off hand.
Personally, I would see the opposite more likely: Have a GS in hardware on PS3 and emulate the EE and rest along with it. This would spare the headache of emulating the low latency high bandwidth eDRAM and if I remember correctly, Fafalada sees emulation of the EE as an easier task given the GS is used in quite unique ways for fullbuffer effects which would quite challenging to say the least. I'd have to dig up the thread though.
Still, at this point: we don't even know what really is in RSX, so there really isn't much point in arguing over what is more complicated without knowing "with what (CELL / RSX) you're supposed to emulating something that at this point is unknown (EE / GS / EE + GS)".
Personally, I would see the opposite more likely: Have a GS in hardware on PS3 and emulate the EE and rest along with it. This would spare the headache of emulating the low latency high bandwidth eDRAM and if I remember correctly, Fafalada sees emulation of the EE as an easier task given the GS is used in quite unique ways for fullbuffer effects which would quite challenging to say the least. I'd have to dig up the thread though.
Still, at this point: we don't even know what really is in RSX, so there really isn't much point in arguing over what is more complicated without knowing "with what (CELL / RSX) you're supposed to emulating something that at this point is unknown (EE / GS / EE + GS)".
Phil said:
See, EE and GS is the least of Sony's problems. It's that 48GB/s EDRAM bandwidth inside the GS that's the real biatch
Where are they gonna take that out from?!Easy, as I already stated, if they include the GS in hardware (Note: The GS + the eDRAM is on the same die already). Truth, is we don't know what they're putting in for a fact, so who are we to discuss what is challenging and what not? Especially when we don't even have an idea with what they're going to emulate it, given we still don't know the details of RSX.
One option is data compression over the existing BW. But all this has been said before, in the other epic BC thread, so a forum search will come up with all the answers and all the questions.
mckmas8808
Legend
Shifty Geezer said:
Yeah that thread should be called the BC Bible. It had lots of answers.:smile:
seismologist
Regular
london-boy said:See, EE and GS is the least of Sony's problems. It's that 48GB/s EDRAM bandwidth inside the GS that's the real biatch
There's only 4mb Edram on the GS. I'm sure it wont be too difficult to squeeze that from the L2 cache. Probably fairly trivial problem to work around. I dont see any issue with PS2 emulation on the PS3.
It seems like the biggest difficulty is in emulating the emotion engine. But Cell lends itself to that task nicely. And I dont think this is a coincidence. It seems like Sony has had BC planned from the get go.
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seismologist said:
Squeeze from where? There's less than 2MB total cache on Cell. Hardly trivial.
You might not see any issues with it, but you're not Sony
seismologist
Regular
london-boy said:Squeeze from where? There's less than 2MB total cache on Cell. Hardly trivial.
You might not see any issues with it, but you're not Sony
If I were Sony it would be even more trivial since I'd have all of the details
. But It's actually less than 4mb since for most games, half of that is allocated for the frame buffer.seismologist said:If I were Sony it would be even more trivial since I'd have all of the details
Exactly. That would mean splitting some memory between the main memory on PS3 and the Cell cache. Frame buffer here, rest there... All from existing games with no rewriting. PS2 games are not coded with standards in mind, one game does something one way and another does it another way. It's not like trying to run old DirectX games on new hardware. Completely different. Again, not trivial.
Could be wrong, and i'd love to be, but that's the impression i get.
Sony will have a much easier time with BC than MS in my opinion. I'm surprised that MS are bothering at all considering that it is "impossible", but too many people viewed it as a selling point for them not to try I guess. They did start late, because they gauging how important it was to people, with the hope that they wouldn't have to at all.
Johnny Awesome
Veteran
None of this will matter much in the end.
london-boy said:
Exactly, but then again, a *very* fast cache could make up for memory shortcomings if it can reload/fetch data quick enough in and out to make it a virtual 4 MB memory space. Given the implications though and the fact that it is a 48 GB/sec bandwidth and the low-latency eDRAM gives, *I* see EE emulation as an easier task. On the other hand, having a rather simple rasterizer with eDRAM in there seems like a waste to me if it can't be used in any other way apart from backwards-compatibility. And again, we still don't know what's built into RSX - maybe, they have something in there that could help the process significantly?
Regardless, Sony claims backwards-compatibility with 13'000 titles across both last consoles and I see no reason why they would state something that confident if it were clear that it's too big of a task. In fact, after 2 very successful generations, not having backwards-compatibility now would be a desaster (since many, as my self, see it as some sort of standard to expect from the PlayStation brand) and so I see that Sony factored this in as a necessity from the very beginning. It's something that will contribute in mindshare being passed on to the next generation and will ultimately be a factor in many of today's PlayStation owners who have an extensive library and a slowly old and breaking PS2. The importance of this should not be underestimated, thus I am very confident that Sony's claim will hold true, even if the accurate tested number in the end is + / - 1000 games or so that no one knows anyway.
Yep, I'm converted. If I could just communicate accurately now...Shifty Geezer said:
This guy already said exactly what I meant (in case you were wondering):mckmas8808 said:
valioso said: