Het grote Xbox 360 en PS3 topic

CPU: Cell (1 PPC + 7 units) vs X360 Cpu (three PPC cores)

X360 advantages and disadvantages
- much easier to program for 3 symmetric processors than an asymmetric processor
- strong single thread performance, but can only run limited number of threads
- multithreading is difficult to program for but NO WAY near as hard as for the cell
- Best described as a jack of all trades approach

Cell Advantages and disadvantages
- The cell is a massively parallel vector processor
- excellent for running multiple floating point tasks such as (game engine, encoding and decoding video)
- Difficult to program for -- ALL software has to be optimized
- Poor single thread performance
- NO hardware Branch prediction, Extremely poor at running complicated branched code (like A.I. code)
- Highly specialized approach, the cell is first and foremost an MULTIMEDIA processor that is best suited for HDTVs and a gaming consoles processor second. It offers extremes -- very good at running game engine, very poor at A.I. code.


GPU:

Today's top of the line 6800ultra has 16 pixel pipelines and 6 shader pipelines and is made up of 222 Million Transistors

X360 advantages and disadvantages
- ATI's next gen GPU (the R500) has a as unique architecture -- UNIFIED vertex/shader and pixel pipelines. It has 48 of these units that are automatically assigned a function
- Easier to program for but has a less higher theoretical peek than independet pipelines
- 10MB framebuffer that allows for "Free" anti-aliasing but limited resolution to 720P. For higher resolutions you "upsample"
- Unknown number of transistors (look for this number in the future)

PS3 GPU:
- officially stated to have 300 Million transistors with fixed pixel and vertex pipelines. Numbers not disclosed. If 6600GT is about 160 Million transistors, the 6800ultra 222 Million -- it is very likely that the PS3 GPU has 24 pixel pipelines and about 10-12 shader pipelines. I find it very easy to believe that the this GPU will be about twice as powerful as a 6800Ultra
- independent pipelines are faster BUT are harder to program for


Memory:

X360
512Mb of unified DDR3 memory with is shared by BOTH the GPU and CPU. Flexiablity is the obvious advantage. Disadvantage is that they have to be shared. Game developers can split the memory any way they like 50:50, 30:70 etc

PS3
256MB XRD for the cell
256MB DDR3 for the GPU

advantage is that the each has its own faster memory but each is limited to 256mb. While the CPU in the X360 can have a max of 512mb, the cell is stuck with 256mb.

Bandwidth:

X360
• 22.4 GB/s memory interface bus bandwidth
• 256 GB/s memory bandwidth to EDRAM
• 21.6 GB/s front-side bus

256GB/s from the 10mb frame buffer gives the X360 GPU a major advantage; it means the R500 isn’t limited by bandwidth and allows for free Antialiasing and a host of other effects. But the cost is that internal resolution is realistically limited to 720P. They may find a way around it. The original PS2 had on-die 4mb frame buffer. The game cube had off-die 2mb frame buffer.

PS3
Main RAM 25.6GB/s
VRAM 22.4GB/s
RSX 20GB/s (write) + 15GB/s (read)
SB< 2.5GB/s (write) + 2.5GB/s (read)

Pretty standard.

Video Output:

X360
Single DVI-output support sall HD resolutions (including 1080P and 1080i). Note that most games will probably be rendered at 720P but upsampled to 1080P like GT4 did with the PS2.

PS3
Dual HDMI (copy-protected DVI that combines audio) so that you can hook up two HDTVs. HDMI is a new format.
BUT for those of you who tried doing this on your computer, if a game runs @ 1080P single TV, you have to drop the resolution down on each TV to 720P so that you can have both.


The rest are extras

That only increase costs and don’t make gamming any better. PS3 has a lot of fat

Dual eithernet
Built-in wi-fi
Bluetooth
Multi-types of flash memory slots (SD, memory stick etc)
blueray

The above probably adds $100 extra to PS3

Conclusion
X360 and PS3 are about the same in power but approach it with different philosophy. X360 is less powerful BUT more flexible and easier to program for. PS3 is theoretically more powerful but less flexible and harder to program.

Ben de hele dag op forums bezig met de Xbox360