Graphics: 500 MHz Vs. 550 MHz

[priteshmodi]

Wow... I actually wrote out a thought-filled article when I read your original post. Then when I finished writing it I refreshed to see what other people had said only to get your second post.... *Sigh* What a waste of time this was. Well I guess I'll post what I wrote anyways, although it all feels kinda useless now.

Horse power is not the only factor in the more powerful car debate and the same is true with the whole MHz/GHz race.

In the case of cars, more raw power could be used for speed or for towing capacity. First you have to define what you mean by "more powerful". Obviously a Ford truck at 550 HP will be faster than a 500 HP Mustang. However, the Mustang will be faster. Which one is "more powerful" depends on what aspect of performance you're looking at.

The horsepower of a cars engine is not directly comparable to the frequency of a graphics processor. The power generated by an engine can be used for many things as stated above. The frequency of a GPU is just how often the states of items being processed are updated. In the debate of the Xenos vs RSX (which are the two frequencies you've listed) what matters more is how many items are being dealt with at any given time; the efficiency. If you were to compare this to your car analogy (which I personally wouldn't), this quality would be defined by how many passengers the car was built to carry. It would be more like a race between a supercar and a high end luxury car to carry 100 passengers from point A to point B. The supercar can only carry 2 passengers but can travel marginally faster than the luxury car but the luxury car can carry 5 passengers.

Why this makes all the difference between the RSX and the Xenos is because the RSX's architecture is static. What's there is there and can only be used the way it exists. There are a given number of texture pipes and a given number of shader pipes (I'm a little rusty on the numbers but I believe it's 24 and 24 or 24 and 16, respectively). The Xenos has 48 pipes but they are dynamic. Each pipe can perform the tasks of either a texture or shader pipe. So say we have a shadow heavy moment in a game with simple textures. The RSX would utilize what it has been designed to use for shadow processing, namely the 24 pipes while the texture pipes might go under utilized. The Xenos Unified Shader can use more than 24 for these situations in order to process the image quicker and would be using all the pipes at all times (all times is unrealistic for anyone who knows more about execution units, but the efficiency is vastly superior to the old method).

So in a one on one performance match up I'd say more often than not, the Xenos would provide higher performance. But the entire dynamic changes when the RSX gets help from the Cell. That's something I haven't looked much into with all this school keeping me busy.

As for my credentials, I am a 4th year student in Electrical Engineering(/Computer Engineering) at the University of Waterloo. I've had jobs involving iPhone development, .NET and ASP development, and some other software related jobs. I've dabbled a bit in DS and Wii game design but don't have much to show for it with time restrictions.