Is DirectX throttling Xbox 360 performance?

[obonicus]

That's not the way it was for 360 however - Microsoft had a specific patch for Halo 2 that allowed such functionality through a bit of extra code, a kind of patch (just realised that it runs at a higher resolution than Halo 3 ). I think this is possible because already on Xbox1 you could patch games?

Right, but I'm just skeptical of the idea that simply using a library ensures portability. Easy portability's an old promise with a spotty track-record (not talking solely about consoles here, clearly). Now, what I know of console development comes almost entirely from reading this forum, but it seems that there's been a lot of talk about how the 360 allows you to do neat stuff by exploiting its hardware peculiarities (like aforementioned EDRAM) while in this thread we're hearing about how 360 developers are able to abstract such things away and use only DirectX. (If I were to wager, based on my own software development experience and Murphy's law being what it is, I'd bet that what you see the most of is suboptimal in both regards -- not 'to the metal' enough to fully exploit the hardware, not abstract enough to avoid having to rewrite substantial amounts of code later on -- joker's 'patch it out' seem to bear this out somewhat.)

 

[grandmaster]

That's not the way it was for 360 however - Microsoft had a specific patch for Halo 2 that allowed such functionality through a bit of extra code, a kind of patch (just realised that it runs at a higher resolution than Halo 3 ). I think this is possible because already on Xbox1 you could patch games?

Like AlStrong says, wasn't it just extra AA but still being upscaled? I'm not sure it's native 720p.

 

[Chisholm]

Like AlStrong says, wasn't it just extra AA but still being upscaled? I'm not sure it's native 720p.

That's right. Xbox games are rendered at 480p 4x MSAA.

 

[Fafalada]

Right, but I'm just skeptical of the idea that simply using a library ensures portability.

It doesn't.

I've seen a 360->PC conversion that was estimated by an overly optimistic tech-lead to take 2 man-weeks (pretty much in-line with expectations in this thread). The actual thing took 3 months to get to a working state and another 3 months of optimization to hit min-spec target performance.
And that's just the back-end tech part of it.

There's also a world of difference between (up/down)porting something that is still being developed, or a classic that has been out for 3-4 years prior.

 

[joker454]

Right, but I'm just skeptical of the idea that simply using a library ensures portability.

It doesn't ensure it, but it makes it significantly easier especially if the studio uses reasonable dev practices, which many already do since the prospect of transitioning the 360 build of any game to other platforms is high as the 360 build is usually the primary build. Ultimately, if there is a layer then one just has to emulate the layer for compatibility. No layers means that the hardware and all it's idiosyncrasies must be emulated which as we've seen can be very challenging.

 

[forumaccount]

Most of the discussion in this thread is based on false assumptions. The original article linked was a huge pile of speculation based on someone's twitter account. Microsoft have done a lot to address the concerns the blog poster raised and many games today are most likely taking advantage of this.

 

[grandmaster]

Actually it was based on direct discussion with someone producing an Xbox 360 game in the here and now, and the follow-ups here are certainly interesting in how other developers perceive the API.

 

[FirewalkR]

Has anyone given a better (or correct) example for grandmaster to use in the article instead of the forest one? I kinda speed-read through the thread and didn't quite catch one.

 

[Weaste]

Actually it was based on direct discussion with someone producing an Xbox 360 game in the here and now, and the follow-ups here are certainly interesting in how other developers perceive the API.

Which goes right out of the window if the don't go with the same processor architecture (CPU). I don't think that they will, and if that is the case, it's not a matter of patching but a total recompile at the very least.

 

[TheChefO]

You're all talking as if Microsoft didn't already do this with the 360, for instance Halo 2's 720p support.

When did they do this?

I heard all kinds of hoopla about halo2 running better on xb360 bla bla bla, but when I popped that sucker in, it looked like a dog. It clearly wasn't running 720p.

Did they come out with a patch later (after launch)? My box was bought about six months after launch.

 

[egoless]

Delete

 

[grandmaster]

That still looks like upscaled 480p with 4xMSAA as AlStrong said earlier.

 

[rekator]

That still looks like upscaled 480p with 4xMSAA as AlStrong said earlier.

Yes, like all Xbox games on 360… But people generally don't note the difference in the term "render at xxxxp" and "xxxxp Native".
The fact, and Bungie indicated this, it's that 360 scale Xbox game to 720p after they got a 4xMSAA so you got a fine xbox game on 720p or 1080p, but not native!

 

[Arwin]

That still looks like upscaled 480p with 4xMSAA as AlStrong said earlier.

You're right. I googled a bit and it's also 4:3 upscaled to widescreen, not native widescreen, apparently. So not that much effort then, in the end it was just the basic upscaling functionality. That wasn't how it was presented back then though.

And it would have been possible too, I think .. the original Xbox could already output a native 720p, couldn't it?

 

[Shifty Geezer]

Right, but I'm just skeptical of the idea that simply using a library ensures portability.

I know enough PC programs on DirectX that aren't perfectly portable between PCs which prove a library does not in itself ensure portability

Libraries are really about virtualising the hardware, so a program is written for a 'virtual machine' and translated to the specific hardware. This moves the problem of compatibility from each and every application to the one implementation of the library. As is inevitable with any hardware virtualisation designed for multiple differing hardwares, the more it's virtualised, the less efficient it'll be. It would be possible for MS to craft some pretty efficient API for console only, knowing the ins and outs perfectly, but if they're wanting to maintain the API as a PC platform too, there are going to be limits. They could then open up the hardware so developers can bypass the higher level API and write closer to the metal to extract more performance, but that will break compatibility with different hardware. Going forward, the only real compatibility guarantee is the Wii-method. Take your current console, squeeze a few or the same processors onto one board, and release it as the new console.

 

[rekator]

And it would have been possible too, I think .. the original Xbox could already output a native 720p, couldn't it?

I found this list of games, but don't really known if is native resolution or 720p support…

 

[swaaye]

Xbox can do up to 1080i. I chipped mine for fun and set the homebrew dashboards and console emulators to run 720p. Xbox Media Center will upscale video to 1080i using the GPU, but it can't handle real HD video content cuz the Celeron is too slow.

Old Xbox really steps ahead of Wii in this way, for homebrewers.

 

[Silent_Buddha]

Yeah I've since retired my Xbox 1, but it served me well for MANY years as a home media center.

I've since replaced it with a fulltime HTPC in all the rooms of the house. Although many of those HTPCs are just terminals to a WHS media server.

Regards,
SB

 

[TheChefO]

Thanks for the replies guys.

That's what I thought was going on with Halo2. This confirms the theory that publishers would not want to see their games significantly upgraded without being compensated.

However ... I think a very interesting take would be to produce a DLC patch where the game would be rendered at a higher resolution with some other visual goodies like AA AF and an upgraded texture pack.

THAT would help users to transfer seamlessly AND keep publishers happy, and heck I wouldn't mind paying a bit more for it.



I'd actually like seeing halo3 running at 720p with 4xAA I'd pay $5 for that.

 

[betan]

Yes, like all Xbox games on 360… But people generally don't note the difference in the term "render at xxxxp" and "xxxxp Native".
The fact, and Bungie indicated this, it's that 360 scale Xbox game to 720p after they got a 4xMSAA so you got a fine xbox game on 720p or 1080p, but not native!

They seem to indicate something else here:

The Xbox 360 will correctly scale the HD image to suit your TV’s resolution.

I'd say, they stealthily implied it's HD rendered.