Microsoft's Xbox 360, Sony's PS3 - A Hardware Discussion
by Anand Lal Shimpi & Derek Wilson on June 24, 2005 4:05 AM EST- Posted in
- GPUs
Will Sony Deliver on 1080p?
Sony appears to have the most forward-looking set of outputs on the PlayStation 3, featuring two HDMI video outputs. There is no explicit support for DVI, but creating a HDMI-to-DVI adapter isn’t too hard to do. Microsoft has unfortunately only committed to offering component or VGA outputs for HD resolutions.
Support for 1080p will most likely be over HDMI, which will be an issue down the road. If you’re wondering whether or not there is a tangible image quality difference between 1080p and 720p, think about it this way - 1920 x 1080 looks better on a monitor than 1280 x 720, now imagine that blown up to a 36 - 60” HDTV - the difference will be noticeable.
At 720p, the G70 is entirely CPU bound in just about every game we’ve tested, so the RSX should have no problems running at 720p with 4X AA enabled, just like the 360’s Xenos GPU. At 1080p, the G70 is still CPU bound in a number of situations, so it is quite possible for RSX to actually run just fine at 1080p which should provide for some excellent image quality.
You must keep one thing in mind however; in order for the RSX to be CPU limited and not texture bandwidth limited at 1080p, the games it is running must be pixel shader bound.
For example, Doom 3 is able to run at 2048 x 1536 at almost 70fps on the 7800 GTX, however Battlefield 2 runs at less than 50 fps. Other games run at higher and lower frame rates; the fact of the matter is that the RSX won’t be able to guarantee 1080p at 60 fps in all games, but there should be some where it is possible. The question then becomes, as a developer, do you make things look great at 720p or do you make some sacrifices in order to offer 1080p support.
One thing is for sure, support for two 1080p outputs in spanning mode (3840 x 1080) on the PS3 is highly unrealistic. At that resolution, the RSX would be required to render over 4 megapixels per frame, without a seriously computation bound game it’s just not going to happen at 60 fps.
Microsoft’s targets for the Xbox 360 are far more down to earth, with 720p and 4X AA being the requirements for all 360 titles. With a 720p target for all games, you can expect all Xbox 360 titles to render (internally) at 1280 x 720. We’ve already discussed that the 360’s GPU architecture will effectively give free 4X AA at this resolution, so there’s no reason not to have 4X AA enabled as well.
Most HDTVs will support either 1080i or 720p; those that natively support 720p will simply get a 720p output from the 360 with no additional signal processing. We’d be willing to bet that the game will still render internally at 720p and rely on either the Xbox 360’s TV encoder to scale the output to 1080i, or you can rely on your TV to handle the scaling for you. But for all discussion here, you can expect the Xbox 360 GPU to render games at 1280 x 720 with 4X AA enabled.
The support for 4X AA across the board is important, because on a large TV, even 720p is going to exhibit quite a bit of aliasing. But the lack of 1080p support is disturbing, especially considering it is a feature that Sony has been touting quite a bit. The first 1080p displays just hit the market this year, and the vast majority of the installed HDTV user base will only support 720p or 1080i, not 1080p. In the latter half of the Xbox 360 and PS3 life cycle, 1080p displays will be far more common place but it may be one more console generation before we get hardware that is capable of running all games at 1080p at a constant 60 fps.
In the end, Sony’s support for 1080p is realistic, but not for all games. For the first half of the console’s life, whether or not game developers enable AA will matter more than whether 1080p is supported. By the second half, it’s going to be tough to say.
Microsoft’s free 4X AA is wonderful and desperately needed, especially on larger TVs, but the lack of 1080p support is disappointing. It is a nice feature to have, even if only a handful of games can take advantage of it, simply because 1080p HDTV owners will always appreciate anything that can take full advantage of their displays. It’s not a make or break issue, simply because the majority of games for both platforms will still probably be rendered internally at 720p.
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jotch - Friday, June 24, 2005 - link
#20 well that can't be right for the whole consumer base, as I'm 24 and only know other adults that have consoles and alot of them have flashy tv's for them as well, I do. I think if you look at the market for consoles it is mainly teens and adults that have consoles - not kids. Alot of people I know started with a NES or an Atari 2500, etc and have continued to like games as they have grown up. Why is it that the best selling game has an 18 rating?? (GTA: San Andreas)The burning of the screen would be minimal unless you have a game paused for hours and the tv left on - TV technology is moving on and they often turn themselves off if a static image is displayed for an amount of time. So burning shouldn't occur.
nserra - Friday, June 24, 2005 - link
All the people that i know having consoles is kids (80%), and their parents have bought an TV just for the console, an 70€ TV.....Who is the parent that will let kids on an LCD or PLASMA (3000€) to play games (burn them).
Or there will be good 480i "compatibility" in games, or forget it....
#17 I agree.
fitten - Friday, June 24, 2005 - link
#14 There are a number of issues being discussed.For example, given the nature of current AI code, making that code parallel (as in more than one thread executing AI code working together) seems non-trivial. Data dependencies and the very branch heavy code making data dependencies less predictable probably cause headaches here. Sure, one could probably take the simple approach and say one thread for AI, one for physics, one for blah but that has already been discussed by numerous people as a possibility.
Parallel code comes in many flavors. The parallelism in the graphics card, for instance, is sometimes classified as "embarassingly parallel" which means it's trivial to do. Then there are pipelines (dataflow) which CPUs and GPUs also use. These are usually fairly easy too because the data partitioning is pretty easy. You break out a thread for each overall task that you want to do. You want to do OpA on the data, then OpB, then OpC. All OpB depends on is the output data of OpA and OpC just depends on OpB's final product. Three threads, each one doing an Op on the output of the previous.
Then there are codes that are quite a bit more complex where, for example, there are numerous threads that all execute on parts of the whole data instead of all of it at once but the solution they are solving for requires many iterations on the data and at the end of each iteration, all the threads exchange data with each other (or just their 'neighbors') so that the next iteration can be performed. These are a bit more work to develop.
Anyway, I got long-winded anyway. Basically... there are *many* kinds of parallelism and many kinds of algorithms and implementations of parallelism. Some are low hanging fruit and some are non-trivial. Since I've already read that numerous developers for each platform already see low hanging fruit (run one thread for AI, another for physics, etc.) I can only believe they are talking about things that are non-trivial, such as a multithreaded AI engine, for example (again, as opposed to just breaking out the AI engine into one thread seperate from the rest of game play).
probedb - Friday, June 24, 2005 - link
Nice article! I'll wait till they're both out and have a play before I buy either. Last console I bought was an original PlayStation :) But gotta love that hi-def loveliness at last!#3 yeah 1080i is interlaced and at such a high res and low refresh the text is really difficult to read, it'd be far better at 1080p I think since that would effectively be the same as 1920x1080 on a normal monitor. 1080i is flickery as hell for me for desktop use but fine for any video and media centre type interfaces on the PC.
A5 - Friday, June 24, 2005 - link
You know, the vast majority of the TVs these systems will be hooked up to will only do 480i (standard TV)...jotch - Friday, June 24, 2005 - link
#14 - here here!jotch - Friday, June 24, 2005 - link
#10 - sounds to me like they're way ahead of they're time, future-proofing is good as they'll need another 6 years to develop the PS4 - but the Cell and Xenon will force developers to change their ways and will prepare them for the future of developing on PC's that eventually have this kind of CPU chip design (ref intel's chip design future pic on the first page of the article), like the article says the initial round of games will be single threaded etc etc...You might get alot of mediocre games but then you should get ones that really shine bright on the PS3, noticeably Unreal 3 and I bet the Gran Turismo (polyphony) guys will put in the effort.
Pannenkoek - Friday, June 24, 2005 - link
I'm quite tired of hearing how difficult it is to develop a multithreaded game. Only pathetic programmers can not grasp the concept of parallel code execution, it's not as if the current CPU/GPU duality does not qualify as one.knitecrow - Friday, June 24, 2005 - link
you'll need HDD for online service and MMOPhow many people are going to buy a $100 HDD if they don't have to?
LanceVance - Friday, June 24, 2005 - link
"the PS3 won’t ship with a hard drive"If that's true, then will it be like:
- PS2 Memory Card; non-included but standard equipment required by all games.
- PS2 Hard Drive; non-included and considered exotic unusual equipment and used by very few games.