On a GeForce 285, 3D Visualizer’s isosurfaces ran perfectly OK. Makes sense as well on special “professional” silicon, the two lighting calculations would be run in parallel.īut a couple of years ago, I got a rude awakening. On a Quadro, the performance difference used to be, and still is, negligible. Makes sense, considering that OpenGL’s lighting engine has to do twice the amount of work. I don’t recall exactly, but the difference was significant but not outrageous, say a factor of 2-3. From way back, on a piddly GeForce 3, I know that frame rate drops precipitously when enabling double-sided surfaces (for those who don’t know: double-sided surfaces are not backface-culled, and are illuminated from both sides, often with different material properties on either side). Well, I don’t have a CAD application at hand, but I have 3D Visualizer, which uses double-sided surfaces to render contour- or iso-surfaces in 3D volumetric data.
Could it be that these two features were specifically targeted for crippling in the GeForce driver, because they are so common to “workstation” applications, and so rarely used in games, to justify the Quadro’s price tags? No, right? What’s common in CAD? Wireframe rendering and double-sided surfaces. But wait: the quoted performance difference is for “professional” or “workstation” applications. So, is the Quadro a lot faster than the GeForce? According to web lore, it is, by a large factor of 10x or so (oh how I wish I could find a link to a benchmark right now, but please read on). Granted, the Quadro 6000 has 6GB of video RAM to the GeForce’s 2GB, but that doesn’t explain the difference.
So, why are professional-level cards so much more expensive? For comparison, an “entry-level” $700 Quadro 4000 is significantly slower than a $530 high-end GeForce GTX 680, at least according to my measurements using several Vrui applications, and the closest performance-equivalent to a GeForce GTX 680 I could find was a Quadro 6000 for a whopping $3660. What are their differences? Obviously, gamer-level cards are cheap, because the companies face stiff competition from each other, and want to sell as many of them as possible to make a profit. There are gamer-level cards, and professional-level cards. One of the mysteries of the modern age is the existence of two distinct lines of graphics cards by the two big manufacturers, Nvidia and ATI/AMD.
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