The purpose of this post is simply to help the community with it's understanding of what exactly the Xbox 360 is. Beyond being a general hardware and specifications guide, I hope to bring a deeper understanding of the Xbox 360 hardware and its abilities.
Before we begin: This post will not be free of opinion, though IT WILL BE CLEARLY MARKED AS SUCH using an asterisk (*) at both the beginning and end of the statement, and will be written in the first person. Any major points the community would like to voice may be added in a similar format. I will do my best to cite all factual information, though note I will make use of Wikipedia
, a site that could possibly contain false information. Wikipedia was not my initial source and I have confirmed the information is correct- I simply use it due to it's convenience. This guide will not cover hardware features such as wireless controllers etc. but will be focused on the core of the system. Finally, I ask that any questions be sent to me by PM so as to keep this thread clutter-free and allow an educated discussion of the 360 hardware. I will edit to update and answer questions to the best of my abilities.
So let's get started.
To begin, we will do a general examination of the basic hardware components. If you've seen all this before feel free to skip ahead where we will go more in-depth with specific hardware topics.
Like any computer system, the Xbox 360 is made up of the following components:
1.)Central Processing Unit
2.)Graphical Processing Unit
6.)Hard Drive (or flash storage)
7.)DVD-ROM (input, storage)
8.)Human Interface Device (in this case most likely the standard controller)
9.)Operating System (not a part of hardware, but has an effect on the use of hardware)
Now that we've covered the bare basics of what makes a gaming system we'll explore exactly how Microsoft filled this list to make the Xbox 360. Central Processing Unit (CPU)
- Microsoft acquired rights to the Power PC architecture created by IBM to create the triple-core 3.2ghz "Xenon" processor. Graphics Processing Unit (GPU) -
ATI was tasked with the job to create the Xbox 360 "Xenos" GPU, made of two separate dice; the main GPU and the daughter die containing 10MB of E DRAM. The whole shebang runs at a decent 500mhz. Memory
- The Xbox 360 utilizes 512 MB of shared GDDR3 Random Access Memory. An additional 10MB of E DRAM is available to the GPU. Motherboard
- Includes a Megabit Ethernet connection, 3 USB ports, A/V output, radio transceiver (for controllers/headsets) in addition to other standard motherboard hardware. Power Supply
- The Xbox 360 has an external power supply to keep it's figure trim and attractive. It has a rating of 203 Watts. Updates to the system have reduced the watt rating of the newer power supplies. Hard Drive
- The standard Xbox 360 has a 20GB hard drive, though about 5GB are reserved for system use. DVD-ROM
- The 360 includes a pretty standard DVD-ROM drive with no notable difference from that of it's PC brothers. Controller
- Similar to the original Xbox, but featuring the guide button and shoulder buttons. Operating System
- No doubt written by Microsoft, it utilizes system resources to ensure the hardware is keeping in line, and allows the Guide, marketplace, and all other parts of the GUI to function.
Here's the fun part, a nice in-depth look at these specific parts of the Xbox 360 hardware. Central Processing Unit - The Xenon
Technology: IBM Power PC
Process: 65nm, originally 90nm
Transistor Count: 165 million
Clock Rate: 3.2ghz
Threads Per Core: 2
L1 Cache Per Core: 32KB data, 32KB instruction
L2 Cache: 1MB shared
L2 Bandwidth: 51.2GB theoretical
SIMD Support: VMX128
Execution: In Order only
Performance: 9.6 Billion Dot Products, 116 Gigaflops theoretical
At the time of its inception, the Xenon was not what you would call a traditional CPU. It was designed to have 3 symmetrical processor cores from the start due to data available to Microsoft and its partners pertaining to the specific needs of processors in the current generation. Each of the 3 processor cores handles two hardware threads simultaneously, though this is not a limit on the number of possible software threads. In total, the Xenon may execute up to 6 hardware threads per cycle. The Xenon has a cycle rate of 3.2ghz and was originally based on 90nm technology. The new 65nm process allows the same processing potential with half the energy and cooling requirements.
The three cores share a 1MB L2 Cache, and *In My Opinion, this could be a system limitation due to the fact that PC processors generally execute less than 6 hardware threads yet often make use of larger amounts of L2 Cache.* Due to the fact that all 3 cores are identical general purpose processing cores, porting code built for Intel/AMD PCs is an incredibly simple process compared to any other available console. The Xenon does not include an out-of-order execution architecture (essentially something that adds to the complexity of the processor in order to boost performance) as a trade off to allow all 3 cores to fit on a single 90nm die. Additionally, the reduced complexity also reduces power consumption. It is important to understand that the Xenon is not as powerful as the last generation of standard single core processors when it comes to running single-threaded applications. In order to maximize potential extra care must be taken to properly multi-thread the software to be run on such an architecture. It is likely that this multi threading advantage over traditional hardware will not be apparent until later in the consoles life cycle. At the launch of the 360 no game engines were able to take advantage of more than a single of the three processor cores due to software (read: game engine) limitations. Since then software support slowly makes use of more and more of the 6 hardware threads, but there is likely quite a bit of potential left in this piece of hardware. Unfortunately, due to the fact that the performance of each core when compared to single-core processors is behind the times, you won't see anything spectacular being done with the Xenon that isn't possible on a desktop computer, though it's multi-threading advantage will likely keep it up to mid-to-high-end PC standards for years to come.
Due to the implementation of VMX128 the Xenon chip excels at Scalar mathematics, what some would call general processing. Due to this addition, it was arguably more effecient than traditional processors at the time. According to Microsoft, it is important that the CPU be a powerful general processing component in order to make use of the most recent development libraries. Essentially, this means the developer does not need to learn the new hardware and live with its specific ups and downs, but instead they may make use of the latest coding techniques, allowing for the perfect balance between true hardware support and effecient coding. Graphics Processing Unit - The Xenos
Technology: ATi R500
Process: 90nm, apparently updated to 65nm, possible cross between 65nm and 80nm
Transistor Count: 337 million
Clock Rate: 500mhz
Shaders: 48 unified pipelines
Sorry about the delay. I will continue this sometime this week. Merry Christmas All!
<message edited by ravenguard88 on Wednesday, December 26, 2007 1:32 AM>