Central Processing Unit



Intel I7 2700k Central Processing Unit


Central Processing Units

I will be looking at the types of CPU's you can have, the speed & cache they can handle in correlation to gaming systems such as the Xbox 360 & PlayStation 3 and how data is transferred through the cpu with data buses & addresses. I will be providing my examples by looking at the CPU's which Xbox 360 & PlayStation use and comparing these in a overall analysis.

So what is a CPU?

A CPU is essentially the key player to the system, its the brain of the entire system where the main calculations and operations take place from other parts of the system. For example if you were to open a program the CPU would essential sort the process of it to be opened, sorting out where the information will go to and be stored for operation, sending information through data buses, address buses & finally stored in registries and prepared for the chip to use these instructions & data. 

CPU - Fetch, Decode, Execute cycle:

It works in this operation when fetching and understanding information:

1. Fetches data & Instructions from the RAM (Random Access Memory)
2. These are then put into the registers for the CPU
3. The CPU then fetches the next item to be processed
4. It then puts this into the data bus
5. The information in the RAM then moves along the address bus
6. The CPU then has to make sense of the received instructions
7. The CPU decodes the instructions set for that type of CPU
8. The chip is then prepared for the execution of the data
9. Data is then executed and the operation takes place

When the CPU is running a task these are the steps it takes to achieve this, depending on the type of processor the system has depends on how fast this can be achieved. I will not evaluate the CPU's which are installed on the two consoles and see how they perform against each other.

Xbox 360 Central Processing Unit:

The Xbox 360 was the first console to include a tri core processor in a dedicated gaming console with it featuring a 3.2 GHz PowerPC Tri-Core Xenon processor which a fairly fast & durable processor for games processing. This was a good CPU however it has both disadvantages & advantages for the gamers & Microsoft. The processor itself at release was a very good and reliable CPU, however within the space of 2 months it was already out matched and out dated by better CPU's which were cheaper and faster. As games hadn't developed much passed the previous Xbox Original a extremely powerful processing unit wasn't needed however, when larger more power extensive games were released due to the new 'unlocked' hardware the consoles had it caused a problem for gamers. Games would play more slower and sluggish compared to other platforms like the PC where more powerful CPU's could be bought and installed, and due to Microsoft choosing a fairly cheap & low-end processing meant that limitations to how games could be created for the console were caused. 

Processor Specs:

1. Tri-Core Processor
2. 128x128 bit Registry
3. 1MB Level 2 Cache 
4. 51.2 GB level 2 bandwidth per second
5. 165 Million Transistors
6. 21.6 GB per second front side bus

However in 2006 more costs for the processor were cut due to the processor size was cut from 90nm to 65nm making the processor cheaper to manufacture and reduce the cost slightly. This was then implemented into the newer models at the time in 2007, this added a slight boost of speed to the processor as it included more transistors & heat output from usage was reduced. 

Another upgrade was made in 2010 when the Xbox 360 s was released with the processor reaching a size 45nm. This again would have cut the costs for manufacturers and made it an overall faster system to run, outputting less heat for a longer lifespan. 

Although these changes were made the processor remained the same build and speed, meaning that it still only included a tri-core Xenom with 32kb per core of level 1 cache memory & 1MB of level 2 cache, this fell behind the more recent & advanced CPU's available in the market today. 

PlayStation 3 Central Processing Unit:

The PlayStation 3 was released after the Xbox 360 so had more opportunity to host a more powerful & adequate CPU for gaming. The PlayStation 3 featured a different CPU with it using a microprocessor instead of a main processor like the Xbox 360, this was locked to one core at 3.2ghz however was able to transmit data more efficiently with the use of 1 PPE (Power Processing Element) & 8 SPE's (Synergistic Processing Elements) which ran the processing of the console. This type of CPU is dedicated to processing multimedia elements or vector based architecture meaning it would provide the efficient power needed for the PS3. 

The overall ideology for the use of such processors is so it could essentially make a pathway between computer processing & graphical processing making them work hand in hand, creating more efficient & faster speeds of processing. This taken into consideration they had actually designed this processor before the release of the Xbox 360, where Microsoft took the idea of the processor and implemented this into their own IBM processors. 

Processor Specs:

1. 3.2ghz Processing power
   
2. 256MB Rambus XDR DRAM
3. 230.4 GFLOPS in single precision floating point operations
   
4. 100 GFLOPS double precision operations
5. 128x128 bit registry
6. 90nm now 45nm
7. 512 KB Level 2 cache
8. 64 KB level 1 cache

Although it is a different kind of processor it has created a basis for very powerful CPU's used in computers and other systems with the use of a single microprocessor container several different processing elements to act as various cores to the processor like a standard CPU would. The processor hasn't been changed since its first implementation in the first model of the console, however the changes to 'nm' have been made to reduce costs & reduce heat production whilst operating. 

Evaluation between the CPU's:

Although both consoles have similar processing power it is hard to draw a conclusive evaluation between the two due to their difference design and style per console. The Xbox 360 would be seen as the more powerful processor with the tri-cores being implemented running a clocked speed of 3.2ghz per core, however the Cell Microprocessor the PlayStation runs slower, however theoretically has more processing cores for more data to pass through every second. The clock speeds are the same however they both process their data differently making a conclusion hard to make between the pair. 

As games have become more CPU & GPU extensive the move PlayStation took to combine processing power between the two of them would have benefits over a standard CPU, however as it doesn't benefit from the additional dedicated cores, it would still lack in terms of power & performance.