Xbox365 Home Page  

Opening the Lid on Xbox 360

by UtahSaint
9/12/2005
 Image
Source:Electronic Design

At Hot Chips, Microsoft unveiled architectural details of the key chips that have been developed for its Xbox. More recently, Infineon released details of three additional chips it has developed with Microsoft for the Xbox 360. Also at Hot Chips,Toshiba researchers described a critical audio/video I/O chip expected to surface in Sony's Playstation 3 when it debuts sometime next spring. The SCC, a "super companion chip" with A/V interface, works with the so-called Cell Processor. Unveiled at ISSCC earlier this year, the Cell Processor is a highly parallel compute engine, developed jointly by IBM Corp., Sony, and Toshiba.

Keys to the success of both systems are: breadth of functionality, quality of video and audio, and ease of programmability. Both the Xbox and PS3 promise to deliver the most realistic and highest-performance game graphics to date, rivaling the best graphics workstations but at consumer costs.

"While the (Xbox 360) has the muscle to power awe-inspiring graphics, audio, and online play thanks to its 720p/1080i (HDTV) output, a 16x9 cinematic aspect ratio, anti-aliasing for smooth textures, and full surround sound, it also has the intelligence to serve as an all-in-one entertainment device that plays CDs, DVDs, MP3s, and digital content from an array of devices, such as portable music players and digital cameras," said Robbie Bach, Microsoft's chief Xbox officer.

Xbox product group VP, Todd Holmdahl, added that Xbox 360 designers focused on achieving a balance among system components, rather than aiming for great theoretical performance in any one component. The latter approach could mean lots of performance left on the table as a result of system bottlenecks.

"Right from the start, we built the system as the hardware instantiation of our software vision-that systems should be extremely powerful when running the type of software that game developers build," said Holmdahl. "This meant that we had to look very carefully at where bottlenecks happen when running game systems, and project what this would look like in the next generation. We analyzed hundreds of Xbox 1 games in detail, and we have great insight into the future due to the innovations that happen on our Windows platform."

The Xbox 360 CPU chip consists of three symmetric Power PC cores running at 3.2 GHz. Each core includes data and instruction caches of 32 kbytes each, and the chip has a shared 1-Mbyte L2 cache that is eight-way set associative. Additionally, each core includes a customized vector floating-point math unit (the VMX128), and can run two program threads. Holmdahl noted that the key here is the six hardware threads available. "This matches where we predict game engine utilization will peak," said Holmdahl. The symmetric nature of the cores and the shared cache makes it easier to move code between the cores, as well as implement communication and synchronization. "Multi-threaded simulation code is hard to write," he said, "and using elaborate DMA controller and DSP-style programming, as in previous generations, complicates developers' lives and is wasteful of their time."

The CPUs can provide high-bandwidth data streaming support with minimal cache thrashing by using a 128-byte cache line size. A tight data streaming capability between the CPU and the graphics processor unit (GPU) is also available. The GPU can read 128 bytes at a time from the L2 cache and it provides low-latency cacheable writebacks to the CPU. The GPU also shares Direct3D (D3D) compressed data formats with the CPU to at least double bus bandwidth for graphics data.

Download VMX128 Scheme Here Download ATI GPU SchemeHere

A 5.4-Gbit/s front-side bus offers 10.8-Gbyte/s read and 10.8-Gbyte/s write speeds. Supporting the custom CPU is a 500-MHz GPU developed in conjunction with ATI Technologies. The GPU includes 48 parallel unified shaders and 10 Mbytes of embedded DRAM (a custom memory chip co-located in the same package as the GPU) for 256-Gbyte/s frame buffering. Rounding out the system hardware support are 512 Mbytes of 700-MHz GDDR3 memory with a 22.4-Gbyte/s memory interface bus bandwidth; a 12X, dual-layer DVD; and a 20-Gbyte hard drive that's standard on the premium model and an option for the core version. The system employs a unified memory architecture that allows the 512 Mbytes to be shared between the CPUs and the GPU with no partitioning headaches for the programmers.

Support from Infineon includes a removable solid-state memory unit, a single-chip wireless game-pad controller, and an advanced security chip. In the memory unit, Infineon crafted a custom memory controller and developed the embedded software that runs on the chip. For the security chip, the company created a custom solution based on its proven authentication technology. The game-pad controller eliminates the cables needed for game play, thus freeing the players from the tethers of wired controllers.

According to Holmdahl, most game/entertainment systems have a significant limiting factor, such as a lack of sufficient memory to feed the CPU and GPU, not enough bandwidth between system components, or an inability to apply processing resources automatically to a changing load profile. "Those and other limitations and restrictions have been dealt with in the design of Xbox 360," Holmdahl asserted. "The Xbox 360 was designed from the ground up to map to exactly what game developers told us they needed."

Holmdahl cited the GPU as one example, with its improved raw shader power over earlier Xbox systems. The 48 parallel shader ALU pipelines are dynamically scheduled and up to 24 billion shader instructions/s can be executed by the pipeline. "This means that the GPU dynamically adjusts to the incoming stream of work that the gaming program is sending it. It also allows the GPU to dynamically schedule around events, such as waiting for data from memory, that would normally block ALUs from processing. GPU resources are kept as active as possible without programmer intervention." The pixel fill rate can hit 4 billion pixels/s (eight per cycle) and the geometry engines can deliver up to 500 million triangles/s. Texture fills can be done at up to 8 billion bilinear filter samples/s.

Moreover, the GPU can optimize vertex or pixel shading automatically for each game without the developer having to write extra code. The embedded DRAM and high-speed frame buffering effectively provides free anti-aliasing to eliminate the jagged edges characteristic of earlier game systems. "The embedded DRAM is unique to Xbox 360 and can process information about 40 times faster than Xbox 1, while allowing for roughly ten times more bandwidth than the competition," Holmdahl asserted. "With the special logic on the memory die we can process the information there without having to send it back to the core GPU. This means no signal aliasing, as well as the ability to process a great deal of information quickly, resulting in more pixels, faster, and the delivery of crisp, realistic images. The GPU also has a tesselator to provide smooth, round silhouettes."

"A traditional memory architecture will get 'fill-bound' as it tries to read and write to memory to build the scene," Holmdahl explained. "This is especially true of next-generation visuals that require high scene complexity, high dynamic range, HD resolutions and anti-aliasing."



Related News, Images & Links

Features & Interviews
» Feature : E3 And Gamer Dissapointment on Sunday, 7 05 2006
» Feature : The World Embraces Xbox 360 As E3 Draws Near on Wednesday, 19 04 2006
» Feature : Origen Revealed on Tuesday, 27 09 2005
» Feature : In Response To Peter Moore%27s Interview on 1up on Thursday, 19 01 2006
» Feature : Xbox 360 in Japan: Who Cares? on Tuesday, 12 07 2005
» Feature : Why Xvid, Mkv and Subtitle Support Are Vital For The Xbox 360 on Monday, 2 07 2007
» Feature : Microsoft Unveils Wave of New Products and Services at CES on Sunday, 7 01 2007
» Feature : Microsoft Announcements @ German Games Convention on Wednesday, 23 08 2006
» Feature : Xbox 360 Inventory Surge + Spring Games Lineup on Tuesday, 21 03 2006
» Feature : Xbox 360 Launch Lineup Announced on Tuesday, 4 10 2005
» Feature : The X06 Summary on Wednesday, 27 09 2006
» Feature : Full Dashboard Update List Revealed With Video on Friday, 30 11 2007
» Feature : Xbox 360 Gets HD-DVD External Add-On on Wednesday, 4 01 2006
» Feature : E3 News Gallore For Xbox 360 on Tuesday, 9 05 2006
» Feature : Fall Update: Browse Friends Lists of Other Xbox Live Members on Monday, 26 11 2007
» Feature : Xbox365 Lost Planet: Extreme Condition Giveaway on Sunday, 7 01 2007
» Feature : Ready To Be Broke? Xbox 360 E3 07 Games Round-Up on Tuesday, 10 07 2007
» Feature : Xbox 360 To Offer Hi-Def TV Shows Via Live [Update] on Monday, 6 11 2006
» Feature : Xbox 360 Pricing and Details Blowout on Wednesday, 17 08 2005
» Feature : Japanese Publisher Love For 360 ...Finally on Monday, 25 07 2005
» Feature : Xbox 360 Widens The Gap Over PS3 on Thursday, 17 01 2008
» Feature : Monster Xbox 360 Faceplate Collection on Tuesday, 4 07 2006
» Feature : Wanted - Classic RPGs On Xbox 360 on Friday, 9 12 2005
» Feature : When’s The Price Falling? on Monday, 25 06 2007
» Feature : Introducing - The Xbox Live Diamond Card on Thursday, 22 12 2005
» Feature : Xbox Live Reaches 6 Million Members on Tuesday, 6 03 2007
» Feature : Xbox 360 Day One Launch Line-Up on Monday, 14 11 2005
» Feature : Xbox Info Roundup From Microsoft on Monday, 12 06 2006
» Interview : Xbox Support Group Program Manager on Sunday, 10 09 2006

News
[+] More News


Also See


grandaddygame
X365 Member
Avatar
Posted 9/13/2005
Yeah, couldn't have said it better myself.
Posts: 370
Member: 3400
IP: i.am.a.member

without a vision the people fail


videogamer
X365 Member
Avatar
Posted 9/13/2005
Where's the idiots guide on this? And was this in english?
Posts: 511
Member: 3566
IP: i.am.a.member

...


ProJect™
X365 Member
Avatar
Posted 9/13/2005
That pixel fill rate has to be wrong because the Xbox1 has a fill rate of 4.8 billion a second.
Posts: 170
Member: 3367
IP: i.am.a.member

...


grandaddygame
X365 Member
Avatar
Posted 9/13/2005
well the original box put out 116 million triagles vs 500 million for x360
Posts: 370
Member: 3400
IP: i.am.a.member

without a vision the people fail


BlackLizard
Heckler
Avatar
Posted 9/13/2005
I just want to know where Elizabeth went. Havent heard from her forever. Just Coola. We need to see some good fantasy hack and slash games on the 360. I'm just that simple.
Posts: 0
Member: None
IP: 71.96.94.191

...


Coola
X365 Member
Avatar
Posted 9/13/2005
Originally Posted by: BlackLizard
I just want to know where Elizabeth went. Havent heard from her forever. Just Coola. We need to see some good fantasy hack and slash games on the 360. I'm just that simple.
what are you trying to say... i'm not.. GOOD enough for you? she's more woman than me?? PSFFFSAFLKSDFJA;tvasdf
Posts: 710
Member: 1837
IP: i.am.a.member

[Coola@Xbox365.com]


xbox360mods
X365 Member
Avatar
Posted 9/14/2005
nah your both woman enough
Posts: 40
Member: 4193
IP: i.am.a.member

...


hj
Heckler
Avatar
Posted 9/14/2005
bhnhgj
Posts: 0
Member: None
IP: 65.43.156.66

...


hj
Heckler
Avatar
Posted 9/14/2005
ghfh
Posts: 0
Member: None
IP: 65.43.156.66

...


BlackLizard
Heckler
Avatar
Posted 9/14/2005
That was a funny response, but we ARE going off topic here. I have'nt wrote anything in these forums for quite some time, but I have been going to this website since it began and have been a big fan of the XBOX since it was born. I really want to believe in Microsoft and have always wanted them to win a big part of this kind of entertainment. Sony has made a big impact with their Champions of Norath series of games, even a version of it on the PSP. These kinds of games are my favorite and would LOVE to to see a great "Champions" type game on the 360. That is why Elderscrolls is a good start. Sony knows that these are money makers and I would like to see Microsoft strike up their own. Survival horror is another great genre for me. Thank god R.E. is coming!
Posts: 0
Member: None
IP: 71.96.94.191

...


Satanicmouse1
X365 Member
Avatar
Posted 9/14/2005
if youve been going here so long why havent you registered? 0_o
Posts: 821
Member: 3590
IP: i.am.a.member

I find your lack of faith disturbing


fatguy8000@hotmail.com
Heckler
Avatar
Posted 9/16/2005
man its going to suck
Posts: 0
Member: None
IP: 167.93.8.250

...


fatguy8000@hotmail.com
Heckler
Avatar
Posted 9/16/2005
the ps3 suck too and the nitendo thing too xbox is going yo kick there ass off @!*% sony
Posts: 0
Member: None
IP: 167.93.8.250

...


videogamer
X365 Member
Avatar
Posted 9/18/2005
calm down fatguy.
Posts: 511
Member: 3566
IP: i.am.a.member

...


blackmath
X365 Member
Avatar
Posted 9/18/2005
BlackLizard - the almost exact kind of game as Champions of Norrath is available on the Xbox as the "Baldurs Gate" series of games - same engine, same gameplay. Check out "The Bard's Tale" too.
Posts: 124
Member: 3353
IP: i.am.a.member

...


Brownface Killah
X365 Member
Avatar
Posted 9/19/2005
I used the Cell processor, and it's no good! Xbox 360's 3 cores ran much more smoothly and the cell processor many i/o errors.

PS3 will die within months of inactive sales results. Only people who will buy it will be those who want both systems. But how many can afford such a thing.
Posts: 2
Member: 3872
IP: i.am.a.member

I run this joint


BabiBoi318
X365 Member
Avatar
Posted 9/21/2005
i just got on this, yall may have already answered this question. Its about changing gamertags at any time you want...what happens when someone or more than one changes there gamertag as well...how do you know which one is which?????
Posts: 2
Member: 3880
IP: i.am.a.member

...


BabiBoi318
X365 Member
Avatar
Posted 9/21/2005
people on your buddy list...i forgot to add that part!
Posts: 2
Member: 3880
IP: i.am.a.member

...


OBrien
Heckler
Avatar
Posted 9/23/2005
Will the Xbox 360 at launch have a HD DvD ( or Blue-Ray) Drive in it ? Or am I going to have to buy a player when the new formats of DvD come out?
Posts: 0
Member: None
IP: 24.214.168.35

...


hi
X365 Member
Avatar
Posted 9/25/2005
XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX XBOX
Posts: 3
Member: 4195
IP: i.am.a.member

...


ixicoolaixi
Heckler
Avatar
Posted 9/27/2005
sad is all i can say
Posts: 0
Member: None
IP: 68.48.226.99

...


moose
Heckler
Avatar
Posted 10/3/2005
cookies in the pan and the freanch frise are sizilin
Posts: 0
Member: None
IP: 65.0.192.59

...


PaleRider
X365 Member
Avatar
Posted 10/11/2005
The only thing I want to know, will it play previous gen games for the current xbox?
Posts: 2
Member: 3939
IP: i.am.a.member

...


LoL pwn l33t hax0r
Heckler
Avatar
Posted 10/12/2005
Noob.
Posts: 0
Member: None
IP: 84.65.127.26

...


Hambone08
X365 Member
Avatar
Posted 10/17/2005
Will the XBOX 360 be capable of System Linking with the original XBOX
Posts: 1
Member: 3962
IP: i.am.a.member

...


vecha
X365 Member
Avatar
Posted 10/20/2005
i heard it will link with it....
Posts: 2
Member: 3975
IP: i.am.a.member

...


homeless guy with many co
Heckler
Avatar
Posted 11/2/2005
It will play "Top-Selling" Xbox games

If someone on xbox360 is playin a BC xbox game they can play with a person playin the same game on the original xbox.
Posts: 0
Member: None
IP: 142.179.138.207

...


seeekPS3
X365 Member
Avatar
Posted 11/22/2005
People Will Buy PS3 theres no doubt in my mind Xbox will fade in time. The question is whats after this. What would you want next for the future generation systems oh yeah SOCOM RULES!
Posts: 2
Member: 4080
IP: i.am.a.member

...


seeekPS3
X365 Member
Avatar
Posted 11/23/2005
is it true that it can link up with the pc?
Posts: 2
Member: 4080
IP: i.am.a.member

...


Quote - Highlight Text | Click Me
Logout | Clear your Setings
Change Settings
Register Username
Please Note You Must be 13 or over to post.
 Un-Registered users IP address (
38.107.191.98 ) Will be visible to Everyone
If your post is in any way profane, racist, sexist or is particularly nasty, we reserve the right to yank your comments and ban you from posting. If you are banned, and feel it is in error, please Click Here to send us your groveling reasons....
 

XBOX365 Marketplace .