Sacred 2: Preview on the forthcoming Physx patch
In late March Sacred 2 is supposed to be upgraded with Nvidia's Physx. PC Games Hardware presents the first screenshots and delivers technical details.
In the course of the Scared 2 consol launch Ascaron wants to deliver an enhanced version with Physx support. Initially the GPU physics support was intended to be part of the retail version but because of technical and time related problems Physx wasn't part of the master code.
Physx in Sacred 2: Requirements
Via patch owners of Geforce graphics cards will receive the benefit of additional physics effects. But Physx will be activated only if a Geforce 8 GPU or better is available. In contrast to Mirror's Edge, where the Physx switch was available even on non-Nvidia systems (the CPU had to do the additional calculations), the Physx support in Sacred 2 will be available to Geforce owners only.
In the game there will be only one switch for Physx: on or off. Producer Chris Grunwald expects that a Geforce 8800 is required to calculate the complex effects in combination with a dual-core CPU in order to display the effects at a decent speed. Most important for Sacred 2 will be the available video memory and a fast hard drive (because of the streaming). To get all features at best quality one should have a GTX 280.
Physx in Sacred 2: The features
Since Sacred 2 has to stay playable without Physx effects and since it is not easy to synchronize Physx features via a Close Net Server structure, the GPU physics are restricted to optional effects. As our comparative pictures show this means: Particles, or mini objects like stones or leaves which are affected by the weather or spells. Those enhancements only affect the visualization and the atmosphere, but not the gameplay. Ascaron took two spells of each character and upgraded them with Physx - the Seraphim's pillar of light for example which sucks in stones or leaves and releases them in a gush of particles.
Phyax in Sacred 2: Ati and CPU
Although the Physx interface supports multi-core processors it is, according to Grunwald, overstrained with the real-time simulation of thousands of particles. This has been tested and the developers noticed that the CPU can't handle the workload easily, since the driver and the architecture would be most critical. Regardless of multiple optimizations on low graphics settings more than 4 fps were not possible with a Quad Crossfire setup on an Intel quad-core system. With an up-to-date Nvidia graphics card the lies performance is, depending on the graphics settings, between 25 and 60 fps. So currently only the performance of the GPU implementation is big enough the display the additional effects at high framerates.
Why is Physx coming now?
According to Chris Grunwald not only lack of time and low performance caused the delay of the Physx support. The takeover of Ageia by Nvidia and the resulting cooperation treaty between Ascaron and the graphics specialist came into effect at a late state of development. Therefore it has not been possible to include the Physx effects into the Master Code because of technical and time related reasons. We also have learned that for the technicians hardware accelerated physics via an external Physx card hadn't been an optimal solutions, since a lot of performance is lost through the Bus transfer from the memory to the physics chip (PPU) and back to the graphics chip (GPU). All those things resulted in a low compatibility with the Streaming technology of the engine. With the calculation via the GPU the implementation of Physx features would make sense as the overall performance is concerned.
As soon as the Physx Patch is available, PC Games Hardware will run tests to check the GPU physics.
More articles related to Sacred 2:
• Sacred 2 running on Notebooks with integrated graphics accelerators
• Sacred 2: Default textures versus Elite Graphics