PS3 Memory Footprint

May 13th, 2007, 01:24 Posted By: wraggster

via innerbits

The release of the 1.60 firmware six weeks ago was recently followed by the release to developers of the corresponding 1.60 SDK. The SDKs always come out a few days after the firmware so that Sony can iron out any bugs, issues and complete the documentation for the new and changed features.

Ozymandias recently did an comparison between the 360 and the PS3, and their memory footprints. Some of the numbers used for the PS3 are slightly out of date, and thanks to this release, we have obtained access to the latest memory footprint of the various key system utilities.

First, the base memory footprint of the PS3 OS in main memory has been reduced from 56 MB to 52 MB. These values will lead to some confusion, as we’ve previously reported that the memory footprint was 64 MB. 8MB of memory was given back to developers sometime before Christmas, and now a further 4 MB has been returned. Currently, as of SDK 1.60, the PS3 operating system takes up 52 MB of main memory and 32 MB of graphics memory (84 MB total). As a comparison, the Xbox 360 still only uses 32 MB of shared memory for all its system utilities.

We have also learned that processing-wise, games are expected to maintain at least 30 frames per second, regardless of how much CPU time is used by the OS. Specifically, there is a Sony technical requirement that states that titles cannot rely on the CPU processing speed. There is no explicit ceiling set on how much processing time the OS can use through its higher priority threads. Of course, Sony will make sure whatever is performed in the background will have very minimal impact on processing time, but the lack of an explicit cap concerns us.

Finally, we present a breakdown of the memory requirements for various key system utilities. In order to make use of them, developers must allocate the specified memory amounts to the OS. These allocations are done in the form of Memory Containers:

As of SDK 1.60, developers can use standard PS3 message dialogs at no extra cost. The standard on-screen keyboard still requires 7MB of memory.
Developers can now choose to support the Remote Play functionality (which allows players to play their PS3 titles on their local wireless LAN using their PSP. Remote Play requires 8MB of memory to be allocated to it.
The various utilities providing saving, loading, and reading off the hard disk now require no more than 5MB of memory to be used.
8MB of memory is required for the online startup utility. This includes both supporting online play, and is a requirement for any of the other Network Platform (NP) utilities. There are several NP utilities, but we will only address the most important one next.
Full support of the NP Friend List utility is currently a staggering 24MB of extra memory (on top of the 8MB needed for the startup). This utility provides the support of the NP friend’s list, allowing players to add, remove, block and communicate with their friends along with the corresponding GUI interface. The extraneous demand on memory has been met with with concern from developers. Since this is just the first iteration of the utility, Sony has vowed to reduce the memory impact of the utility to something more manageable (20MB is the rumored target for the next major release expected in late May – early June).
Video chat (supporting up to 6 concurrent users) requires 26MB of memory, while voice chat (supporting up to 12 users) requires 8MB. The utility allowing for in-game microphone configuration is also 8MB.
Finally, developers can choose to support an integrated web browser. The memory cost for a web browser can vary from around 40MB to 90MB+, depending on the web sites being browsed, and the number of windows and tabs used.
We won’t rehash the same argument we have made previously that developers could have benefited from some of these features earlier on, or that functionality such as friends list should not cost developers extra memory. Sony has chosen to go down the route of Memory Containers, using that flexibility to continuously expand their feature list, without forcing all developers to use the same features.

Sony is making every effort to both provide new functionality and dampen the impact on memory. Some of the features being provided (such as the integrated web browser) are unique to the console. However, the friend’s list still represents a hefty investment in memory for now, and we hope that Sony can continue to make every effort to make such core features less of an impact on memory for developers. After all, integrating with the Network Platform is something Sony should encourage in every game. This would go a long way in addressing the lack of consistency in the online experience across the various titles currently available.

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