The ability to "code to the metal" is another area consoles are overestimated. PCs are not struggling to reach efficient use of their hardware, nor are their OSs gobbling up much of the available resources. Processing tasks in a typical PC are not extensive. Games are the most intense application, unless you're doing some rendering tasks, such as video rendering.
Windows 7, a full featured OS that does much more than console OSs, uses up only about 2gb RAM at most, and almost none of the CPU. This is easily verified by a resource monitor, such as that built into Windows. Nor are PC GPUs struggling to reach efficient use. You can monitor exactly how much energy the processor of a GPU is with an electrical meter. As electricity is what powers the transistors and registers in a processor, it's an accurate measure of how much of the hardware's capacity is being used. And it is possible to max out the capabilities of a PC GPU.
Unless we're talking about a vast gulf in manufacturing size, resulting in more efficient energy use, then it is fair to compare PS4 straight across to a PC. Sony themselves called PS4's architecture like that of a PC. They've touted the ease of porting from a PC development environment (where most games are developed, including PS3 and 360). PS4 uses an x86 processor (note that it's x86 and not x64, thus 32 bit, not 64 bit), compatible with modern PC development environments.
So TFLOPs are not all there is to a processor, for instance there is the clock speed, however they are a good indicator of capability. TFLOPs are an indication of how many computations can be performed in a second. Given that the main purpose of a computer is to compute, that should be self evident. And so when you're talking about efficiency, low level access to the GPU can optimize some code, however it can't take a 1.84 TFLOP GPU and allow it to outperform a GPU of comparable architecture and greater processing capability.
Thus things like polygon and texture manipulation and rendering, which are very much dependent on computational ability, are greatly dependent on the processing power of the processor. So when we're talking about chipsets released in relatively similar timeframes, with feature sets that are fairly comparable, that rating is a decent indication of relative ability. And we do know what the GPU is in the PS4: a 7900 mobile variant, a 100W chip, 1.84 TFLOPs, DX11 feature sets, standard shader and texture architecture. No amount of low level coding access will allow that GPU to outperform a 660 Ti, much less a 680.
PS4 will be decent. It's going to be a huge upgrade over the PS3 and 360, both of which are pushing 8 years on the market. Sony fans are going to enjoy it, I'm sure. PCs are ahead of it and will pull further ahead of it in the coming years, both in performance and price. However that's not what really matters. What matters is the games. Buzzwords don't mean much without the software. The Vita versus the 3DS should be evidence of that. Without a compelling software library, no price will compel the market to embrace the Vita over the 3DS. And despite having vastly weaker hardware, a compelling hardware library is all 3DS needs to perform well in the marketplace.
( Edited 02.04.2013 01:13 by jres80 )