Publicly available info - CPUs vs. GPUs

[Neeyik]

One thing that's puzzled me, or rather irked me, over these past few years is the total lack of genuine information that graphics chip manufacturers release in comparison to CPU companies such as Intel or AMD. For example, you can download spec documents that go into huge amounts of detail on the workings of a processor, power consumptions, heat dissipation, and so on. Granted, you're not told everything but you're given sufficient knowledge in my opinion. In comparison, the GPU market is almost pure politics - every "technical" document reads like a party policy brochure, resplendent with buzz words and acronyms.

I understand the basics of marketing and publishing (having worked in management for retail industry for several years); I can follow that the graphics market is very cut-throat and volatile; I can appreciate that you don't want to give away too many of your product's secrets. But why are ATI and NVIDIA so shy at publically releasing genuine facts, figures and limitations when Intel and AMD seem far less reticent with their products?

It would be nice to see hear a comment, however guarded, from Kristof on this

Edit: Just realised that I've posted this in the wrong section...oops...awfully sorry John old chap, etc etc etc

 

[Xmas]

One of the main reasons, if not the main reason, is that developers can (and sometimes have to) go down to the metal on a CPU and sqeeze even the last little bit of performance out of it, while they are barred from graphics chips (or other specialized ASICs) by APIs and drivers.

CPU makers want developers to write the fastest software for their chips. So they hand out all the information necessary. GPU makers do the same thing, but on another level. The tell programmers how to sort triangles, set render states, etc.
And sometimes they publish performance relevant information on their hardware, like the size of the post-transform vertex cache, or throughput of several shader instructions. But they aren't going to publish their microcode.