flipping it and exposing it directly to the cooling solution. ATI thus could achieve higher clock speeds. Radeon 9700 PRO was launched clocked at 325 MHz, ahead of the originally projected 300 MHz. With a transistor count of 110 million, it was the largest and most complex GPU of the time. A slower chip, the 9700, was launched a few months later, differing only by lower core and memory speeds. Despite that, the Radeon 9700 PRO was clocked significantly higher than the Matrox Parhelia 512, a card released but months before R300 and considered to be the pinnacle of graphics chip manufacturing (with 80 million transistors at 220 MHz), up until R300's arrival. Architecture The chip adopted an architecture consisting of 8 pixel pipelines, each with 1 texture mapping unit (an 8x1 design). While this differed from the older chips using 2 (or 3 for the original Radeon) texture units per pipeline, this did not mean R300 could not perform multi-texturing as efficiently as older chips. Its texture units could perform a new loopback operation which allowed them to sample up to 16 textures per geometry pass. The textures can be any combination of one, two, or three dimensions with bilinear, trilinear, or anisotropic filtering. This was part of the new DirectX 9 specification, along with more flexible floating-point-based Shader Model 2.0+ pixel shaders and vertex shaders. Equipped with 4 vertex shader units, R300 possessed over twice the geometry processing capability of the preceding Radeon 8500 and the GeForce4 Ti 4600, in addition to the greater feature-set offered compared to DirectX 8 shaders. ATI demonstrated part of what was capable with pixel shader PS2.0 with their Rendering with Natural Light demo. The demo was a real-time implementation of noted 3D graphics researcher Paul Debevec's paper on the topic of high dynamic range rendering. A noteworthy limitation is that all R300-generation chips were designed for a maximum floating point precision of 96-bit, or FP24, instead of DirectX 9's maximum of 128-bit FP32. DirectX 9.0 specified FP24 as a minimum level for conforming to the specification for full precision. This trade-off in precision offered the best combination of transistor usage and image quality for the manufacturing process at the time. It did cause a usually visibly imperceptible loss of quality when doing heavy blending. ATI's Radeon chips did not go above FP24 until R520. The R300 was the first board to truly