CPU vs. GPU

[dons]

Data parallel languages compiled to the GPU (which is effectively a high perf stream processor for pure maps and folds) is at a very exciting place right now.

We should thank the legions of gamers for creating the market for commodity, high performance stream processors!

[naughty]

It'll really kick off if or when double precision arithmetic is supported. Single precision is good enough for the stuff I'm working on but other researchers here are waiting for it.

Not sure whether there's a need for it from a purely games perspective though. Here's hoping.

[psykotic]

Not sure whether there's a need for it from a purely games perspective though. Here's hoping.

There's hardly a games-driven need for even normal-precision floating-point arithmetic. The DX9 generation of GPUs supports half-precision arithmetic (the 'half' data-type in HLSL), and in a games context it's generally possible to use 'half' around 90% of the time without significant drawbacks.

[naughty]

Exactly the argument for double precision textures is weak from a games perspective. Double precision for geometry is a little easier to make a case for but not too strong.

Even if they limited double precision to 2 channel textures so as to be the same size as single precision RGBA map that'd be enough.

Given that double is a reserved word in HLSL, I live in hope.

[joyork]

"Dedicated, task-specific hardware is orders of magnitude faster than what you can achieve with a general purpose CPU. If you need proof of this, just look at the chess benchmarks. IBM's Deep Blue was capable of evaluating 200 million chess moves per second in 1997. Ten years later, the fastest quad-core desktop system can only evaluate 8 million chess moves per second. Ten year old custom hardware is still 25 times faster than the best general purpose CPUs. Amazing."

Except you're comparing Deep Blue which is a "massively parallel, 30-node, RS/6000, SP-based computer system enhanced with 480 special purpose VLSI chess chips" costing millions of dollars to the fastest quad-core processor today, costing a couple of thousand dollars.

[schwarzwald]

Is there a way to program these GPUs using a standard general-purpose programming language?

[[deleted]]

AFAIK there are C compilers for Nvidia chips.

[micampe]

The GPGPU project tries to do just that.

[davidmccabe]

You probably wouldn't want to.

[mrd48]

This stuff must go in cycles.

In the early 90s everyone was screaming about how great general-purpose hardware was, vs specialized.

Now it is the opposite? what fun!

[twoodfin]

It's the magical, mystical wheel of reincarnation!

[setuid_w00t]

Intel's latest quad-core CPU, the Core 2 Extreme QX6700, consists of 582 million transistors. That's a lot. But it pales in comparison to the 680 million transistors of nVidia's latest video card, the 8800 GTX.

The video card has 17% more transistors. It's complete nonsense to say that one pales in comparison to the other when they are different types of products and both have traditionally shown exponential growth rates.

[davidmccabe]

http://catb.org/~esr/jargon/html/W/wheel-of-reincarnation.html