How did the xbox 360 and ps3 disks run the same games despite different disk sizes?

[gamagama69]

Ive dumped my ps3 and 360 games, and somehow games that should be huge are not. Read dead redumption fits onto an 8gb duel layer dvd (you need to use isos for 360 games so im not sure how big exactly each dumped game is.. Meanwhile many of my ps3 bluray dumps are 10gb or more. The one multiplat game is 5 gigs (dark void)

 

How is this possible? Did multiplat games just need to degrade the console version to fit in the 360 space requirements? Did their multiplayer just be a download? I never had a 360 i was a gc and wii kid.

 

[Rusty Proto]

This sounds like a good excuse to get Andy to do a side by side comparison of each version. Often, they would cut features or compress textures differently to get a larger game onto a system with smaller disks. (Fitting PS2 or Xbox games onto GameCube is one particular example that comes to mind.)

 

Speaking of which, does LMG have a gaming channel?

[dilpickle]

Dual platform games usually went with the lowest common denominator which was xbox and its dvd drive. Only some ps3 exclusive games made full use of the space on Blu-ray. 

[TheVirtualNomad]

On 9/26/2022 at 10:20 PM, dilpickle said:

Dual platform games usually went with the lowest common denominator which was xbox and its dvd drive. Only some ps3 exclusive games made full use of the space on Blu-ray. 

Until towards the end when the 360 went multidisc. (Wolfenstein: The New Order on 4 discs anyone?)

[xXAXONXx]

ps3 cell cpu are powerfull for that time

[TomChaai]

They were never a download. Back then internet and storage was slow so you only download what you paid for, such as a proper DLC, main game updates are tiny, like only a few megabytes.

 

Differences like audio/video/texture compression can all impact game size. On PS3 there is absolutely no size limit, but the disc drive is slower than the 360 one, CLV read mechanism slows it down further because it easily takes 300+ms to seek. So seek reduction is factored in, multiple copies of the same file may be packed into each level file, reducing the need for the laser to run around and the spindle motor to spin up and down to go with it. Since it's a CLV drive, no need to add padding to push file to the outer rim of the disc, the read speed is the same across the entire disc anyway. 

 

The result is bigger PS3 games usually require a preload phase to copy some hot data onto the HDD, resulting in longer game startup time.

 

Xbox 360 used a 12X/16X CAV drive, when there is no read error, the disc always spin at top speed, no need to spin up or down during seeking. DVD laser is much simpler and lighter than Blu-ray laser so it moves a lot faster as well. This results in 100-150ms seek time, way faster than PS3. The 360 was also originally designed to only optionally require HDD, so games are designed to run without it, just slower or reduce some audio/video quality to free up RAM and/or drive I/O. So the game can be run entirely live from the disc. 

 

For smaller games, the disc layout includes intential padding files to push the hot data to the outer rim, taking advantage of faster transfer speeds caused by the CAV read mechanism. Although I have an unverified theory that Xbox took advantage of the DVD-DL OTP design and custome LBA-to-PSN mapping to swap the two layers, making the game always start at the outer rim. I'll need to dig into the original DVD drive hacking thread to understand better.

 

For larger games, clever compression schemes need to be used to reduce file size, also the developers try to use scripted cutscenes instead of movie clips to save space. The original XGD2 standard reserved at least 5mm of the inner radius of the data region as reserved space, not used for game data, also the outermost rim of the disc is intentionally mastered without any data in order to improve disc longevity. This resulted in about 1GB of wasted space on XGD2.

 

Later in the Xbox 360 lifecycle, it became apparent that space is an issue, some games come with 2 discs, one play disc and one install disc, some games ran across multiple discs like the old CD days. MS released the XGD3 format to shave down the reserved partitions to a minimum, recovering the 1GB space, at the cost of them being read at about 4X-6X, so usually only the cold data is stored there, like video or audio assets. XGD3 also took advantage of the DVD standard's "channel bit length" tolerance to squeeze about 3% more data than a standard DVD-DL onto the disc, this not only increases capacity but also makes unauthorized copying harder.

[gamagama69]

On 10/16/2022 at 1:09 PM, TomChaai said:

They were never a download. Back then internet and storage was slow so you only download what you paid for, such as a proper DLC, main game updates are tiny, like only a few megabytes.

 

Differences like audio/video/texture compression can all impact game size. On PS3 there is absolutely no size limit, but the disc drive is slower than the 360 one, CLV read mechanism slows it down further because it easily takes 300+ms to seek. So seek reduction is factored in, multiple copies of the same file may be packed into each level file, reducing the need for the laser to run around and the spindle motor to spin up and down to go with it. Since it's a CLV drive, no need to add padding to push file to the outer rim of the disc, the read speed is the same across the entire disc anyway. 

 

The result is bigger PS3 games usually require a preload phase to copy some hot data onto the HDD, resulting in longer game startup time.

 

Xbox 360 used a 12X/16X CAV drive, when there is no read error, the disc always spin at top speed, no need to spin up or down during seeking. DVD laser is much simpler and lighter than Blu-ray laser so it moves a lot faster as well. This results in 100-150ms seek time, way faster than PS3. The 360 was also originally designed to only optionally require HDD, so games are designed to run without it, just slower or reduce some audio/video quality to free up RAM and/or drive I/O. So the game can be run entirely live from the disc. 

 

For smaller games, the disc layout includes intential padding files to push the hot data to the outer rim, taking advantage of faster transfer speeds caused by the CAV read mechanism. Although I have an unverified theory that Xbox took advantage of the DVD-DL OTP design and custome LBA-to-PSN mapping to swap the two layers, making the game always start at the outer rim. I'll need to dig into the original DVD drive hacking thread to understand better.

 

For larger games, clever compression schemes need to be used to reduce file size, also the developers try to use scripted cutscenes instead of movie clips to save space. The original XGD2 standard reserved at least 5mm of the inner radius of the data region as reserved space, not used for game data, also the outermost rim of the disc is intentionally mastered without any data in order to improve disc longevity. This resulted in about 1GB of wasted space on XGD2.

 

Later in the Xbox 360 lifecycle, it became apparent that space is an issue, some games come with 2 discs, one play disc and one install disc, some games ran across multiple discs like the old CD days. MS released the XGD3 format to shave down the reserved partitions to a minimum, recovering the 1GB space, at the cost of them being read at about 4X-6X, so usually only the cold data is stored there, like video or audio assets. XGD3 also took advantage of the DVD standard's "channel bit length" tolerance to squeeze about 3% more data than a standard DVD-DL onto the disc, this not only increases capacity but also makes unauthorized copying harder.

oh hey thanks i forgot about this thread. yeah i heard that xgd3 was an issue for game dumping, but luckily it doesnt look like any exclusives really used this.

 

thats cool i guess thats why some bluray drives are slower writing dvd than dvd drives