"For the record, the demonstration ran on a 16-core (4 socket, 4 core) Tigerton system running at 2.93 GHz."

Ok, for the record, f**k that. Let me know when it REALLY becomes a reality for the rest of the market out there --- not to mention, it looked like crap served on a platter with the name Fido on the side --- except for the reflections.

-1

Mojo

overall the impression i get is that people hate ray-tracing with a passion
i for one support it. less time spent on shadows, reflections, etc the better
they can instead spend it on what actually counts in the first place

you can see how much effort goes into getting shadows right in options
which is why you've got no, simple, and complex shadow settings
if complex shadows can get thrown in for free then i'm all for it

same thing goes with reflections. just take a look at racing games
see how much of the 'world' they've tried projecting onto the car
if that's thrown in for free then i'd be for it

then you've got things like an rts where it's got the 'mini-map'
which is essentially a 'portal' of the same world except much higher up
"apparently" in ray-tracing its easy to do it (ie. portal view)

would it really be so bad for at least someone to try something different?

"but also by displaying it at a 720p resolution with near-real-time frame rates (14-29 FPS)"

I'm sorry, but what is "real-time" for frame rates? I wasn't aware there was any agreed-upon definition? Are you going by the standard of 24fps for movies? 60 fps for TVs? The human eye being able to see things as quick as 1/200th of a second? (or is it quicker? I forget the study)

Sorry to nitpick, but seems like a rather arbitrary definition. I used to get 22 fps on my Voodoo Rush in Quake 2 and that was silky-smooth fluid to me, back in the day.

The trouble with ray-tracing is that the computing requirements increase in line with resolution. So going from 720p to 1080p more than doubles the processors you need (or doubles the speed they need to run at -- 6GHz is unlikely, but there's always wider SIMD and better instruction throughput).

14 to 28 is a pretty wide variation in framerates, from fast-slideshow to barely-playable. Some of that may just reflect the primitive state of the code, but a lot of it is likely a result of variations in load: as the scene changes the calculation complexity can fluctuate pretty wildly, and (unlike rasterization) there aren't a lot of cheats or caching opportunities available to even things out.

Even more significantly, there isn't any mention of how much memory was used in the demo system. Ray tracing performance is heavily dependent on keeping the entire model in memory (and, as much as possible, in cache). If you can't do that, your frame rates crash. In fact the memory requirements are so strict it may be they used Linux because they could tune the OS memory manager precisely to their requirements.

I guess we'll have to see what Larabee can do, but I still think in the near-medium term raytracing is only going to get used in a hybrid way with regular rasterization, to add some reflections and light/shadow effects.

Of course it makes sense to use it for collision detection -- that's essentially what collision detection does (in effect every game is already ray-tracing bullets and lasers/nails/beams of death etc).

thats pretty damn cool. There must be a way of making a dedicated stream like processor that would do raytracing well (is that what larrabee is?). I remember reading once the processor equivalent of a voodoo 1 card and i was surprised

Personally I quite liked the glass reflections and water clarity...

If you look closely at the video, there's no grass (which would murder a ray tracing engine), and a lot of the textures look pretty glassy and fake.

I think ray-tracing scales almost perfectly with multiple cores, as opposed to rasterization which doesn't (see SLI/Crossfire issues).

Could someone with more experience say whether ray-tracing really is "embarrassingly parallel"?

(This would very much be in-line with the "throw cores at it" fallback strategy, and the reason why we are seeing more talk about raytracing lately)

those pictures were really ugly

Fast enough to be playable sounds reasonable.