The Cell advantage over Xenon isn't too surprising IMHO. When you program SPEs well, and with a workload suited to them, you can get really great efficiency. More so than on the PPE, and more so than on Xenon cores (both of which were really rather sucky "general purpose" cores).That...Is confusing. XBO processor is so much faster than the PS4 in that? Even assuming the PS4 is clocked at 1.6GHz (some benchmarks imply it's faster) and the XBO is 1.75, that's 9% faster, which would put it at about 106FPS in theory. So what's the extra coming from?
And Cell at 3x faster than Xenon? It's faster in some regards in theory, but even then 3x is at the upper bounds, close to double is what you would usually expect with absolutely perfect scaling to each SPU.
I don't agree with this one.A programmer's analogy.
Cell is like thirty or so drunk teenagers and two average teachers trying to herd them. Jaguar is like eight German Army generals.
The teenagers are so drunk that they have to cluster together to walk, but when it comes to breaking ice with bare fists, they will probably be a better fit. The thing is, GPU is like a swarm of intoxicated crows that's even better at it (except they use beaks, but that's just a little implementation detail).
And Cell at 3x faster than Xenon? It's faster in some regards in theory, but even then 3x is at the upper bounds, close to double is what you would usually expect with absolutely perfect scaling to each SPU.
How in the world did you arrive at such a number?
Can we get a tales from my ass for this post?
Like a large butt spewing shit?
there probably not comparable directly, but either way, one would expect a bigger jump in performance after 8 years :/Hmmkay, let's see if I can do a comparison based on gflops.
XBOX360 CPU
3,2 GHz PPC Tri-Core Xenon
77 GFLOPS (theoretical)
XBOX ONE CPU
AMD JAGUAR x86 8x1,75Ghz
112 GFLOPS (theoretical)
----------------------------------------------
PS3 CPU
Cell Broadband Engine CPU 6x3,2 GHz
ca. 100 GFLOPS real/ 230 theoretical(ca. 200 GFLOPS on matrix multiplication)
PS4 CPU
AMD JAGUAR x86 8x1,6Ghz
102 GFLOPS (theoretical)
Well I think that gamedevs need to use the GPU more in this generation, because the GPU GFLOPS went from like 200-300(PS360) to 1,85 and 1,3 TFLOPS.
Stats are from wiki and vgleaks.
Hmmkay, let's see if I can do a comparison based on gflops.
XBOX360 CPU
3,2 GHz PPC Tri-Core Xenon
77 GFLOPS (theoretical)
XBOX ONE CPU
AMD JAGUAR x86 8x1,75Ghz
112 GFLOPS (theoretical)
----------------------------------------------
PS3 CPU
Cell Broadband Engine CPU 6x3,2 GHz
ca. 100 GFLOPS real/ 230 theoretical(ca. 200 GFLOPS on matrix multiplication)
PS4 CPU
AMD JAGUAR x86 8x1,6Ghz
102 GFLOPS (theoretical)
Well I think that gamedevs need to use the GPU more in this generation, because the GPU GFLOPS went from like 200-300(PS360) to 1,85 and 1,3 TFLOPS.
Stats are from wiki and vgleaks.
It's not just the clock rates either. The Jaguar IPC is much better for branchy general purpose workloads than the last-gen CPUs, but still pretty distant from an Intel Core [whatever]. So you really have a factor of 3 or so difference in single-threaded CPU performance between PS4 and a decent (not even going into enthusiast territory) gaming PC.That 1.6 ghz really handicaps the cpus. You can't multithread everthing in a game to make up for it. Its better to have those fewer thread running at much higher clock rates.
Why would you put a dog in the trunk?
Mind me asking this probably not bright question, but what makes multithreading so difficult? aren't games running many dozens of processes anyway? can't they just evenly hand these to the different cores?
As far as I can see, even if the Cell is marginally better than the Jaguar CPU at some tasks, it's marginally better at tasks it was specifically designed to excel at.
What's we're seeing is that the 'tablet' CPUs in PS4 and Xbone are very nearly as good at the task that Cell was designed specifically as the Cell, despite the fact that they are low end, general-purpose CPUs.
It's a bit like finding out that your average family car from 2014 has almost the same 0-60 time as a supercar from 2008. Yes, the supercar is still marginally faster, but you still can't fit the family dog in the trunk.
Synchronization, and read-modify-write access to shared resources and data.Mind me asking this probably not bright question, but what makes multithreading so difficult?
Mind me asking this probably not bright question, but what makes multithreading so difficult? aren't games running many dozens of processes anyway? can't they just evenly hand these to the different cores?
Mind me asking this probably not bright question, but what makes multithreading so difficult? aren't games running many dozens of processes anyway? can't they just evenly hand these to the different cores?
Excuse my ignorance as I hardly know anything about the subject and this kinda tech talk in general but what would you say about the PS4/XONE's capabilities in general? Are they really as weak as some people make them out to be or do they have some kind of ''secret sauce'' or is there anything else people might be missing with the architecture/specs?Synchronization, and read-modify-write access to shared resources and data.
Not all parallelization is difficult -- there are problems, such as shading pixels, which are what we call "embarrassingly parallel" -- and that's why it's even possible to use exceedingly parallel computing platforms such as GPUs efficiently. The difficulty comes in when trying to effectively parallelize algorithms which are not embarrassingly parallel. It's not unusual for an efficient parallel version to be far more complicated to design, write, maintain and debug than semantically equivalent serial code.
Consider calculating the sum of all elements in an array (a list) -- a reduction operation. Serially, you jsut iterate over the list and add each element to the total sum until you are done. Probably 3 lines of code.
To maximize parallelism, you need to do something akin to this:
Suddenly you have log(N) time steps, each with synchronization between them, and need to take care of where you are addressing your array in each step and element. And that's just reduction, which is pretty damn simple to parallelize in the grand scheme of things.
I could go on and on about this (I teach a lecture about it after all ) but that's the central idea.
They are weak compared the pc counterparts, where cpu are tons of times more advanced. The only 'new'things it's the high number of ACE in the ps4, but surely can't beat the global performance of the more advanced gpu in the pc market. But will be interesting to see how much will improve the ps4 graphic in the future.Excuse my ignorance as I hardly know anything about the subject and this kinda tech talk in general but what would you say about the PS4/XONE's capabilities in general? Are they really as weak as some people make them out to be or do they have some kind of ''secret sauce'' or is there anything else people might be missing with the architecture/specs?
There's alot of conflicting stories about it actually, some people say they this gen of consoles is so ''weak'' they won't even hold out for 5 years, while others say they are perfectly fine functioning consoles that will bring us great games and graphics in due time. Its kind of confusing. : (I like to believe they are powerhouses though )
weak relatively to PC, overall PS4 and XBONE should be much more capable than PS3 and X360, so we will at the very least get the same gameplay with better graphics than before, so I'm don't be too worried about itExcuse my ignorance as I hardly know anything about the subject and this kinda tech talk in general but what would you say about the PS4/XONE's capabilities in general? Are they really as weak as some people make them out to be or do they have some kind of ''secret sauce'' or is there anything else people might be missing with the architecture/specs?
There's alot of conflicting stories about it actually, some people say they this gen of consoles is so ''weak'' they won't even hold out for 5 years, while others say they are perfectly fine functioning consoles that will bring us great games and graphics in due time. Its kind of confusing. :\ (I like to believe they are powerhouses though )
They are weak compared the pc counterparts, where cpu are tons of times more advanced. The only 'new'things it's the high number of ACE in the ps4, but surely can't beat the global performance of the more advanced gpu in the pc market. But will be interesting to see how much will improve the ps4 graphic in the future.
That strongly depends on what sort of task you're trying to run. If it's a computational task with excellent opportunities for patterned instruction-level parallelism, then yeah, a well-made Cell program has a good shot at winning. But in a lot of cases it probably won't be possible to optimize code for Xenon or Cell to compete with Jaguar; Jaguar simply has a much snappier pipeline for highly sequential code with interesting behaviors, thanks to things like lower execution latency and much less bullshit.CBE has the highest peak performance among all of them. Xbox 360's CPU runs at higher clock speed so will outperform Jaguar in rare cases where code is highly optimized to avoid stalls.
Jaguar will run most code faster, but the CPUs from last gen will run highly optimized code faster.
Synchronization, and read-modify-write access to shared resources and data.
Not all parallelization is difficult -- there are problems, such as shading pixels, which are what we call "embarrassingly parallel" -- and that's why it's even possible to use exceedingly parallel computing platforms such as GPUs efficiently. The difficulty comes in when trying to effectively parallelize algorithms which are not embarrassingly parallel. It's not unusual for an efficient parallel version to be far more complicated to design, write, maintain and debug than semantically equivalent serial code.
Consider calculating the sum of all elements in an array (a list) -- a reduction operation. Serially, you jsut iterate over the list and add each element to the total sum until you are done. Probably 3 lines of code.
To maximize parallelism, you need to do something akin to this:
Suddenly you have log(N) time steps, each with synchronization between them, and need to take care of where you are addressing your array in each step and element. And that's just reduction, which is pretty damn simple to parallelize in the grand scheme of things.
I could go on and on about this (I teach a lecture about it after all ) but that's the central idea.
/hijacksOne difficulty in multithreading is to even out this stuff, so that each core never runs out of work and doesn't spend time being idle. The more sophisticated it gets, the more time you'll need to spend on writing and debugging the code.
They are weak compared the pc counterparts, where cpu are tons of times more advanced. The only 'new'things it's the high number of ACE in the ps4, but surely can't beat the global performance of the more advanced gpu in the pc market. But will be interesting to see how much will improve the ps4 graphic in the future.
Thanks.Thanks godelsmetric, Durante, lightchris, wonderdung for your replies regarding parallelism
weak relatively to PC, overall PS4 and XBONE should be much more capable than PS3 and X360, so we will at the very least get the same gameplay with better graphics than before, so I'm don't be too worried about it
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