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.
Facebook
Twitter
RSS
93 Comments
View All Comments
LanceVance - Friday, June 24, 2005 - link
Excellent article. Definitely the most thorough, informative, well researched article on the PS3/Xbox360.And most importantly, unlike every other article on the subject, it's not strongly biased toward one camp while making comments of substance.
yacoub - Friday, June 24, 2005 - link
I bet the PS3 debuts at a higher price.Also regarding statements made on the Conclusionary page:
--"That being said, it won’t be impossible to get the same level of performance out of the PS3, it will just take more work. In fact, specialized hardware can be significantly faster than general purpose hardware at certain tasks, giving the PS3 the potential to outperform the Xbox 360 in CPU tasks. It has yet to be seen how much work is required to truly exploit that potential however, and it will definitely be a while before we can truly answer that question."--
I find it funny that once again the PlayStation will be the harder system to code games for that take full advantage of its abilities. If trends mimic the past (as they often do) this will lead to a large amount of mediocre games by companies too small to afford the dev time necessary to take real advantage of the PS3's advantages or on deadlines too tight to spend the time doing more.
Furen - Friday, June 24, 2005 - link
It does sound pretty low but (I'm guessing) it's more than enough, I dont think they would have separated the dies unless it didnt lead to a big performance penalty. also, I'm guessing that the 256MB/sec bandwidth between the eDRAM and its processing hardware is 256GB/sec? Microsoft was using that number to inflate their "system bandwidth" total.Woodchuck2000 - Friday, June 24, 2005 - link
And for that matter, 32Mb/s inter-die communications in the Xenos GPU seems low to me:p
Good article though guys!
Furen - Friday, June 24, 2005 - link
Is there any word on the media center extender capabilities on the xbox 360? I think Microsoft mentioned something about that but I'm not sure if that was oficial or not. Just hope they allow us to plug in some video capture device and use it as a dvr eventually.As much as I like sony's playstation, I find it quite boring on the technical side. It seems like they're just throwing everything they can into it but nothing is really that exciting, or useful. Come on, dual-HDMI. I dont see myself having two HDTVs in such close proximity to each other. Gigabit router? Seems like they're desperate to use the extra cpu muscle. I wonder how heavy ethernet traffic will affect cpu usage.
Woodchuck2000 - Friday, June 24, 2005 - link
Surely porting between multi-core PC software and Xenon should be fairly trivial, not fairly Non-trivial as stated in the article...?jotch - Friday, June 24, 2005 - link
I stands for interlaced whilst the P stands for progressive scan. Check out the difference at http://en.wikipedia.org/wiki/720por
http://en.wikipedia.org/wiki/1080i
This should resolve this issue.
AnnihilatorX - Friday, June 24, 2005 - link
1080i = 720p doesn't it? 1080p is the one Xbox 360 doesn't support.These "i"s and "p"s are confusing me
sprockkets - Friday, June 24, 2005 - link
How is 1080i on your tv's? On my 1 year old Mitsubishi native 1080i tv using dvi from the computer at 1080i is basically useless since the text is too small and the image looks like the refresh rate is below 60hz, whereas HDTV broadcasts look fine. Using the other mode of 720x480 looked great.Will HD output from a console be any better than a video card in a computer? Is it just my tv?
Cmon, did you really think nVidia would release something far more advanced for a console than for a video card, or perhaps, more specifically, having it way outperform 6800 ultras in sli?
If you need around a 400w power supply for even non sli setup, what kind of heat and power will these new consoles need anyhow???
Of course I am more interested in how the PS3 will work with Linux more than games hahahahaha, since Sony officially mentioned it.
emmap - Sunday, December 4, 2005 - link
And that's this article, Sony and M$ have missed:it's not the number of megapixels, shader pipelines, CPU / GPU bandwidth, multithreaded or single threaded code which do a great game. It's imagination put in the game, gameplay, artistic art quality, human feeling we get looking at the characters, fun and so on. It's not only mathematics and physics: we don't love a game because it has X millions polygons or run at Y fps, no it's totally different. Just see all the mame fans out there, you'll see that they don't care about the obsolete hardware the game they are playing on, they care about the most important thing about game: ENTERTAINMENT!