ATI Technologies: We Render Two Frames at Once!

ATI Technologies also tried to couple two chips on one PCB for a higher performance as it had no other answer to NVIDIA’s release of the GeForce 256 in the fall of 1999. ATI took a different approach than 3dfx Interactive. The point of MAXX ?that was the name ATI had given to its multi-GPU technology ?was to put two chips on one PCB and make them render different frames simultaneously and then output the frames on the screen alternately. Another name for this technology is Alternate Frame Rendering (AFR).

The performance of the new Rage Fury MAXX graphics card roughly matched the GeForce 256 SDR and was even higher in 32-bit color, but serious defects in the implementation of AFR technology ruined it. Particularly, the two RAGE 128 PRO graphics chips were synchronized by the driver and this negatively affected the latencies when switching between the chips. Quite often the chips fell out of sync and the performance of the card would slump down suddenly or the image would become jerking. Besides that, the peculiarities of MAXX technology prohibited using the Rage Fury MAXX with operating systems other than Windows 98. So, this attempt to issue a multi-processor solution into the desktop graphics market ended in a failure, too.

3dfx’s Last Try

Meanwhile, 3dfx (the company had changed its name) was all beset with troubles. Its solutions that had been the height of technical perfection just recently were now their competitors?inferiors from the architectural standpoint. Their performance didn’t seem high anymore, either. For some reason the company again put its stake on multi-processor configurations, although it had already become clear that such graphics cards would be too complex and expensive to be a bestseller.

So, November 15, 1999, 3dfx announced their new VSA-100 chip that supported 32-bit color and could work in multi-processor configurations. This latter feature was dubbed Voodoo Scalable Architecture (VSA). The new incarnation of 3dfx’s SLI had been greatly improved. Particularly, it permitted that up to thirty-two VSA-100 chips be united in a single graphics array, each chip processing a certain sequence of the frame lines. The length of the sequence could change dynamically depending on the load. The “master?chip then formed the final frame out of the line sequences prepared by the “slave?processors.

Alas, actual graphics cards on the VSA-100 chip took too long to come to market ?NVIDIA with its GeForce 256 and GeForce2 GTS had firmly established itself there. NVIDIA’s chips were not at all slower but were more advanced from the technical point of view as they featured a hardware T&L unit. So, only the dual-processor implementation of VSA saw the light of day as Voodoo5 5000 and Voodoo5 5500 graphics cards. The four-processor Voodoo5 6000 that required a special external power adapter was manufactured in limited quantities and such cards are real curios nowadays.

There were no other attempts from 3dfx Interactive although it had new products with multi-chip architectures on its roadmap. These plans never came true as at the end of 2000 3dfx was devoured by NVIDIA Corporation. The computer world forgot about consumer-class multi-processor graphics solutions for a while.

XGI: An Unfortunate Hybrid

September 16, 2003, another attempt to promote multi-processor graphics cards into market was made. XGI, earlier a graphics division of SiS, announced the Volari series of graphics processors that supported DirectX 9.0 and could work in dual-chip configurations. It looked well on paper: two GPUs with eight rendering pipelines in each could perform wonders, but the actual implementation ruined the concept. Having little experience at building such complex systems, XGI created something in-between 3dfx’s VSA and ATI’s MAXX technologies. XGI took the master-slave concept from the former and the alternate frame rendering from the latter. But the two GPUs were connected via the BitFluent bus with a peak bandwidth of only 2.13GB/s. This automatically created a bottleneck in a system of two Volari V5/V8 GPUs.

Besides that, the chips themselves were so weak that even the topmost model, the Volari Duo V8 Ultra (for details please see our review called Club3D Volari Duo V8 Ultra Review: XGI Volari Family Coming to Graphics Market), could only deliver the performance of the RADEON 9600 XT level, but with a horrible quality of the image and at a price of about $500! No wonder the attempt to come to market with such hardware was a complete failure, and the Volari Duo V5/V8 soon sunk into oblivion.

Looking back at the history of consumer multi-chip graphics cards we see only failures and defeats, as every attempt to promote such a product in the market was ultimately unsuccessful. The idea of using several graphics processors in an ordinary desktop PC had seemed to be buried and abandoned forever, but quite recently NVIDIA dug it out and implemented on a whole new level.