PCTuning fórum

PCtuning píše:Poprvé se informace o novém řešení objevily minulý měsíc, (07/2008) a jak se zdá, prakticky všechny sliby, co se funkční části řešení týče, byly splněny. Společnost LucidLogix představila na právě probíhajícím podzimním IDF (Intel Developer Forum) funkční systému s Hydra 100 čipem. Podle výrobce může jeho čip vyřešit mnoho problémů, které současné multi-GPU řešení mají a přinést také další výhody.

Lukáš Fiala píše:...Server The Inquirer píše, že Intel se rozhodl vybavit Hydrou svou vlajkovou loď mezi motherboardy, DX58SO (čipset Intel X58 + ICH10, patice LGA 1366) s kódovým označením "Smackover". Řídící procesor Hydra 100 bude přítomen na její nové revizi, "Smackover 2"...

Last night we had an interesting chat with Nir Cohen who is the senior product marketing manager at Lucidlogix, as he was vistiing Taipei to talk to some potential customers and he gave us a few more details about the Hydra chip and what it can do.

Although he wouldn't go into too much detail, we did find out some new and interesting aspects on what Hydra can do. First of all, the implementation done by ELSA Japan is not the same setup as that which will be found on consumer motherboards, as the Hydra chip can function in two different modes. To make a replacement for SLI or CrossFireX, the Hydra chip has to be configured to run in graphics performance mode, but ELSA's implementation doesn't work like this, as ELSA is using the chip as a PCI Express controller with some additional functionality.

The Hydra chips have a built in RISC processor which makes it a much more flexible solution than your average PCI Express controller. ELSA's implementation is said to be cheaper than using a Tesla server with four cards from Nvidia, but we'll have to wait and see what ELSA's official pricing will be until we know this for sure. In non graphics performance mode up to four cards can be used, but in graphics performance mode you're limited to two cards at the moment, but Lucidlogix is working on allowing for up to four cards.

We also found out that the interface on the ELSA solution that connects to a workstation or server is using an external PCI Express x1 connection, although as this is only used for transferring data to be computed and already computed data between the CPU and the Tesla cards, this is meant to be more than enough for the intended usage scenarios. We're not sure how this works with other solutions, such as using Quadro cards.

Another interesting aspect is that its possible to cascade multiple Hydra chips, although at the moment this is limited to two chips, but this would allow for more cards to be used. This could at least in theory allow for four GPU graphics cards, but Nir suggested that in the future up to 8 GPU's per Hydra chip could be possible, in theory at least.

For those that are worried that this will be another nForce 200 chip, there's no need to worry as Nir assured us that the Hydra has a TDP of a mere 4W and as such it shouldn't even need a heatsink, although we expect motherboard makers to add one just in case.

The reason why Hydra scales so well is because its the Hydra chip that controls the rendering and Lucidlogix is doing it quite different than the way AMD and Nvidia are doing things. Using multiple graphics cards have so far meant alternate frame rendering, split screen rendering or tile based rendering. Lucidlogix on the other hand is going for object based rendering which is an entirely new approach which means that each GPU get allocated parts of an object of the scene that's being rendered and then the Hydra chip pieces together the small parts into the final frame which is then displayed on the screen.

The proof is still in the pudding so to say, as Lucidlogix has yet to show a running demo of its Hydra chip, but with a bit of luck this should happen during CeBIT which kicks off early next month. So far we're only hearing whispers about potential consumer partners, but again, there's a chance that more details will be revealed during CeBIT.

• Hydra je založena na RISC architektůře, není to jen PCI-Express HUB
• Může pracovat v režimech Alternate Frame Rendering (AFR), Split Frame Rendering (SFR), Tile-Based Rendering (TBR - používalo PowerVR Kyro) a Object-Based Rendering
• V budoucnu možnost připojení až 8 GPU (prozatím jsou podporovány 2)
• TDP je stanoveno na cca. 4W
• Možné uvedení na Cebitu 2009

Object based rendering huh? I'd love to see that work with rendering something even as simple as a cubemap or with Carmack's proposed voxel based terrain renderer. This also renders a Z-only passes a moot point since that requires running all objects through the transform and rasterization stages. Hogwash!

If it was easy to just parcel out individual objects to be rendered to different GPUs AMD and Nvidia would have done it ages ago. How can Lucid do this so easily when they have a lot less information than the graphics guys do about their own hardware?

In terms of RAM, there's no win there. How would Hydra know which objects are more expensive (like which ones are going to be tessellated, or which have the most demanding shaders) or which textures need to go to which card? Some algorithms also rely on maintaining the drawing order of primitives. They're making it sound like you can just split up the objects that belong to the scene and delegate them to different cards without worrying about any dependencies. Sounds like a pile of bull until they offer up some proof that it works.

Weslo píše:moc si neumím představit ten Object-Based Rendering.
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