Kurt Shintaku's Blog

I was reading the comments in a Gizmodo article about the Xbox 360 price drop and I thought I’d take this opportunity to answer some of the… uh… questions from the comments crowd.

COST
Q:  Why is the Elite is worth twice as much as the arcade?
A:  To be clear, the Arcade is $199 and the Elite is $399.  The reason the Elite is more expensive is because it comes with:
– 120GB Hard Drive ($189)
– HDMI Cable ($49)
– Headset/Communictor headset ($29)
There is additive value to purchasing the Elite as a package however if a customer decides that they don’t need the accessories that the Elite has, they can always purchase just what they need ala carte.

Q:  Why is the 120GB hard drive $189 when I can get a 1TB drive at Costco for the same cost?
A:  As with most hardware associated with Xbox 360, the 120GB hard drive is not priced for the sake of making money.  The cost of the drive is squarely the result of the “security-specific electronics” engineered into our storage.  The bottom line is that any given 2.5” drive is generally going to cost X and after that, the drive manufacturer (Seagate, or whomever) has to commit to manufacturing it for the life of the console and such a committal generally implies a slightly higher price.  Once done, the drive often has several customizations – not the least of which is security oriented I/O filtering, all of which raise the cost of the unit.  This I/O filtering prevents anything except an Xbox 360 from putting content on to the drive for execution to prevent viruses and malicious content from spreading to games and Xbox Live. This incidentally, is the reason traditional USB hard drives don’t work for storing anything but media content.  When asked about the PS3’s ability to use external hard drives for storage, the Xbox Dev team basically said that they supposed that Sony isn’t as interested in consumer security as Microsoft is.

PERFORMANCE
Q:  Is Sony Playstation 3 hardware “more advanced”?
A:  The Xbox 360 provides better performance, greater flexibility, and ultimately a better gaming experience than Playstation 3 in most every scenario.  It’s well known that the Xbox 360 has been a much better environment for game developers to write to allowing faster game releases and the ability to release titles for Xbox vs other platforms however disregarding that fact, there are several critical metrics to the gaming experience that Xbox 360 & any other consoles should be measured by:
1) General Purpose CPU Performance
2) Floating Point CPU Performance
3) GPU Shader Performance
4) Memory System Bandwidth
Xbox 360 provably outperforms Sony Playstation 3 in all of these except Floating Point CPU performance which was a deliberate design choice.  Contrary to some erroneous reports CPU-based floating point instruction work is not a very significant element gaming.

Q:  Why doesn’t Xbox 360’s CPU emphasize floating point CPU computation?
A:  Because, put simply, geometric calculations which are what floating point calculations are traditionally used for in games, are handed off to the GPU – not the general CPU.  There is a perception that the 7 DSP processors of the Cell processor makes for superior graphics capabilities because “it has more” and that’s not the case. 
To quote some of the Advanced Technology Gaming gurus we have, “Sony’s CPU is ideal for an environment where 12.5% of the work is general-purpose computing and 87.5% of the work is DSP calculations. That sort of mix makes sense for video playback or networked waveform analysis, but not for games. In fact, when analyzing real games one finds almost the opposite distribution of general purpose computing and DSP calculation requirements. A relatively small percentage of instructions are actually floating point. Of those instructions which are floating-point, very few involve processing continuous streams of numbers. Instead they are used in tasks like AI and path-finding, which require random access to memory and frequent branches, which the DSPs are ill-suited to.”

This is a document that does a great job in comparing the two hardware platforms.

http://cid-00da410c7f7e038d.skydrive.live.com/embedrowdetail.aspx/ProductMaterial/Xbox360vsPS3.xps