PowerVR 2 and Voodoo 3: The Big Men on Campus. 12.8.98 
By: Jarret Griffis 

With the release dates for both the PowerVR 250 and the 3Dfx Voodoo 3 coming ever so close, Cool Info takes a look at what each architecture has to offer.  

Several months ago, NEC announced the PowerVR 250 (PVR250), a 3D graphics accelerator with enough horsepower and features to give any respectable company in the business a run for their money.  However, soon after that announcement, NEC signed a contract with Sega, a console manufacturer that had been heavily maligned due to the unsuccessful Saturn gaming system, that allowed the company to use the PVR chipset in their upcoming Dreamcast console.  After months of inactivity in the press regarding the PC version of the PowerVR, it appears that NEC will be releasing their new accelerator very soon.  The ever-so-innovative citadel of gaming, 3Dfx, has also announced plans to release a new line of products, the Voodoo 3 2000 and 3000, both seem to be complete solutions and, most importantly, fast.  

To put things into perspective, it is necessary to not only take the performance of each accelerator into account, but the way graphics are rendered, as well.  The Voodoo 3 uses Traditional Rendering, which renders all polygons in a scene -- including those that are not exposed to the eyes.  What this does is waste CPU clock cycles, thus causing a performance hit.  The PVR250, on the other hand, uses Tile Based Rendering.  This type of rendering only accounts for the polygons that can be seen on screen, theoretically giving the architecture a performance advantage over a similar accelerator using Traditional Rendering.  This is not always the case, though, as seen with the PowerVR first generation chip, the PCX1, which was outperformed by 3Dfx's current offerings at the time.  

The reason for the slow performance was simple:  NEC's PCX series of accelerators had one serious flaw:  they could only perform comparatively with the Voodoo when their own API was put to use.  In other words, when games utilizing Direct3D began to appear, the Tile Based Rendering method that the PowerVR PCX1 and PCX2 relied so heavily on was simply not used.  Instead, Microsoft chose Traditional Rendering, which gave 3Dfx the clear advantage when running under Direct3D.  So clear, in fact, that anyone running a PowerVR was doomed to fall prey to obsolescence.  

In order to improve the future, one must look at the past.  It seems that NEC has taken in an eye full of their previous infirmities, and intends to redeem themselves with their newly designed PowerVR 250.  According to NEC, the accelerator will host a plethora of 3D capabilities, including 32-bit rendering, advanced texturing (Bi-linear, Tri-linear, Anisotropic, Bump-mapping), per-pixel loadable fog table, and a full polygon setup engine.  On the 2D side of things, the PVR250 comes with a 230MHz RAMDAC and full VGA compatibility.  

As far as performance is concerned, the PowerVR sports a maximum polygon throughput of 5 million per second, a number lower than even the current generation of graphics accelerators.  Considering that today's state-of-the-art computer games rarely push even half that, it is unlikely that the lower number will adversely effect performance.  Fill-rate for the PVR250 is variable, ranging from 200-500 million pixels per second depending on scene complexity.  

Even with NEC's public relations officials lips locked up tighter than Alcatraz in the middle of a hurricane when it came to discussing the PVR250, 3Dfx refused to stand fast.  Increased pressure from nVidia and S3 evoked the creation of the Voodoo Banshee, a product created to compensate for the increased popularity of graphics cards with both 2D and 3D capabilities.  The Banshee, however, failed to deliver the performance that most had hoped for.  Even though the 2D acceleration was excellent, 3D capabilities were somewhat limited, which can in part be attributed to the lack of a second TMU.  

Shortly before the PowerVR announcement, 3Dfx released some information of its own via a press conference at Comdex.  According to various sources, the Voodoo 3 will contain 3D features almost identical to previous generation Voodoo 2 and Banshee accelerators.  This suggests that image quality of the card may not be as vivid or colorful as the PVR250, while 2D speed should be comparable to the Banshee.  When observing performance, the Voodoo 3 2000 accelerator boasts a maximum fillrate of 250 megatexels (very similar to a pixel) per second.  Conversely, the Voodoo 3 3000, geared towards hardcore gamers, has a fillrate of 366 megatexels per second -- polygon throughput climaxes at 7 million for both cards. 

Although the specifications of both the PowerVR 250 and Voodoo 3 are undeniably impressive, what is written down on paper does a great injustice to the consumer.  In order for the PowerVR 250 to be a true power house, it must garner developer support.  And with a version of the PowerVR under the hood of the Dreamcast, the outlook could be a positive one.  For 3Dfx to continue it's dominance, they must reinforce the lead they have by coaxing developers to add to the already immense software library Voodoo graphics has accumulated.  If any of these companies makes even the slightest mistake in their marketing strategy, especially 3Dfx, it could put them forever out of business.  Some skeptics, however, believe that both have already goofed.

The Voodoo series of graphics accelerators has seen leaps and bounds in performance generation after generation, but the architecture for each card has been roughly the same.  Possibly one of the biggest hindrances the Voodoo 3 will have in the future will be the lack of 32-bit rendering capabilities.  As video games start coming out that utilize 32-bit color, the 16-bit palette that has been a trademark of 3Dfx may come back to haunt them.  In present time, 32-bit palette's have not been implemented well enough to fully take advantage of the colors provided.  However, as technology, in software as well as hardware, progresses, this will change drastically.

The possible demise of the PowerVR may lie in its Tile Based Rendering.  Games that utilize this will certainly make the graphics at the heart of the PVR a very pleasing sight.  Although, running games that do not use said rendering may bring the chipset to its knees.  The performance hit incurred, however, is unknown by Cool Info at this time, and this argument may be superficial at best.

Problems aside, both the Voodoo 3 and PowerVR 250 are aiming to rock your world.  The Voodoo 3, with screaming speed, and the PowerVR 250, with a plethora of features and beautiful images, plan to up the ante on performance and visual flair with their new beasts of burden.  The prevailant accelerator for 1999 could very well be one previewed here today.  Then again, we have had some pretty impressive technology sneak up on us in the test labs before... 

Even though there are many types of graphics accelerators out, 3Dfx and NEC are the two companies who started the high-performance revolution with their Voodoo and PowerVR chipsets.  These companies have redefined 3D graphics, and pass or fail, their names will be forever remembed throughout history.