HYDRA renders SLI and CrossFire obsolete?

Lucid, a little-known fabless semiconductor designer, has just announced a new product that could render both NVIDIA’s SLI and ATI’s CrossFire technolgies obsolete. Despite the performance advantages gained using the existing multi-GPU setups, SLI and CrossFire each have drawbacks that prevent many enthusiasts from adopting either. Logic would lead most people to believe that using two video cards together would result in twice the performance. After all, last we checked 1+1=2. However, neither SLI nor CrossFire, despite recent strides, do not scale linearly. In fact, after a full two years of maturing, all NVIDIA and ATI have managed is a performance increase of 40-70% when adding a second card.

Lucid’s new chip, called the HYDRA Engine, aims to bring linear scaling to multi-GPU configurations. What’s more, these multi-GPU configurations are not brand-exclusive. Anyone wanting to pop a new ATI Radeon 4800 series into their 9800GTX rig would theoretically be able to get near-linear scaling from the second card. The secret is in a custom logic for rendering a scene with multiple GPUs. There are two main methods used by current multi-GPU technologies to render a scene. Split frame rendering consists of each card rendering part of a frame. The problem here is that all of the information for the scene has to be synchronized on both cards, which does not allow the combined power of the both cards to be optimally exploited. The other method, alternate frame rendering, has the inherent latency of switching between GPUs involved. HYDRA, on the other hand, splits the graphics work before anything is sent to the GPU, so everything is dependent on the hardware rather than the software. This means that each card’s individual hardware is used up 100% all the time, rather than having anything to do with the other card. This eliminates the need for SLI or CrossFire bridges entirely.

The HYDRA Engine chip intercepts graphics calls from the CPU before it gets to the graphics cards and tells which graphics card to do what. One graphics card might be told to perform a task such as rendering the background geometry and applying to light and what have you, while the other graphics card renders the foreground and applies motion blur. Lucid claims that there is virtually no CPU overhead, which permits the entire scene to be rendered twice as fast; linear scaling. The HYDRA Engine can be applied to configurations with up to 4 GPUs.

There is a slight damper in what would seem to be the single most phenomenal development in graphics technology in the past couple of years: you cant really use it to mix AMD and NVIDIA graphics cards just yet. Currently, Microsoft Windows operating systems do not permit the use of more than one graphics driver. Unless Microsoft re-writes the rules and allows NVIDIA and ATI drivers to be installed on the same system, the HYDRA Engine will only be useful in this capacity on a hacked OS.

Want to know what the craziest thing is? Lucid’s work was made possible thanks largely to $50 million in venture capital funding from none other than INTEL. That should be pretty interesting, eh? AMD/ATI and NVIDIA might want to watch out for this, especially if Intel wants to cut them out of the platform scene for their processors entirely.

You can find a whole lot more information and some neat pictures over at PC Perspective

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