MikeB said:
MikeB said:
MikeB said:
@ crumas2
I find it amusing that some people are arguing that seek times are not important for games stored on optical discs. DVD and Blu-Ray are *primarily* designed to stream data, i.e. - music and movies when are for the *most* part read in a linear fashion. That's why those formats use a large spiral track instead of the concentric tracks and sectors employed by hard drives and diskettes. Hard drives and diskettes are designed for random access, i.e. - programs and separate data files read in a NON-linear fashion.
So what does this tell us? That seek times are VERY important when playing a game that is stored primarily on a DVD or Blu-Ray disc, because the data will to a large degree NOT be accessed in a linear fashion. This is why Oblivion on a DVD has one copy of each data file but on Blu-Ray has several copies of each file placed strategically on the disc... according to Bethesda, the random access times on Blu-Ray were NOT SUFFICIENT to provide acceptable performance:
Sorry with all the trolling I overlooked your actual input.
Of course seektimes and layer switch times are important, like I said so within this thread and commented on to the best of my ability.
Regarding the Bethesda comment:
"Bethesda's Pete Hines also commented that recent reports of data duplication on the PS3 Oblivion disc have been exaggerated, and this technique isn't different from the similar strategy that was employed in the creation of the Xbox 360 game last year."
http://uk.videogames.games.yahoo.com/ps3/previews/the-elder-scrolls-iv--oblivion-68e797.html
But this strategy IMO makes more sense on Blu-Ray as you have lots of available space to take advantage of. |
MikeB wrote:
Copying data layer by layer will yield different results compared to how game data is being read from a dual layer disc during a game. (layer switching)
I recoverd from yesterday, so back on topic.
Of course Microsoft's PR was rather misleading and proper documentation of the various used drives are hard to find. I came across one interesting article from a lead 360 developer, one who designed a 360 exclusive game. Some quotes:
"Some consoles only have a DVD for reading data. How fast we can read data depends on data layout and the quality of the media. Every time we switch layers to read from, it will cost us about 100 ms."
"It is almost always a good idea to duplicate data if it helps to avoid seeks."
Of course with most top 360 titles already hitting the 6.8 GB limit and developers will try to continue to provide more varierty and better quality assets, data duplication on the 360 becomes less of an option.
The full article can be read here:
http://www.gamasutra.com/view/feature/1769/streaming_for_next_generation_games.php
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Someone emailed me a Russian article, it states (translated, chief programmer of Ukrainian studio Deep Of shadows):
With regard to random seek times (equal data size):
Harddrive: 7-20ms
XBox 360 drive: 110-150ms
PS3 Blu-Ray: 50-100ms
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XBox 360 Layer Switch time: 75ms
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(Babelfish) "Load with DVD - example * the average speed - 12 MB/s * seek of 120ms = of 12*0.12 = of 1.44 MB/s is lost * seek+layer of change (200ms) = of 2.4MB/s is lost * Spin up - 2sek = of 24MB/s is lost * 3 seek for reading 0.5 MB: the speed: 7.68Mb/s"
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This part of the article seems to regard data duplication.
(Babelfish translation) "Minimization of a quantity Of seek * all resources of zone - one linear block (files), the duplicates of resources in the different blocks - maximally effective reading * to arrange the dependent files is close to each other * “the shuffle” of the turn of load for the minimization of the length Of seek - group files - is not necessary seek to the catalog, files are located close"
