BioShock Performance with AA

Our benchmarking extravaganza with BioShock concludes with today’s article. In Part 1 we evaluated the performance of today’s latest high-end graphics cards with the game and found that NVIDIA’s GeForce 8800 reigned supreme in DX10 mode, but AMD’s Radeon HD 2900 XT put up numbers besting NVIDIA’s GeForce 8800 GTS and GTX under DirectX 9 mode. Visually there are only subtle differences between BioShock’s DirectX 9 and DirectX 10 modes. Shadows are crisper under DX10, while particle effects like smoke and fog have soft edges. The most obvious difference is in the game’s water ripples.

Under DX9, water ripples are practically nonexistent. Instead a trail of white foam trails your character. Under DX10 water ripples beautifully. We also discovered Irrational integrated a hybrid DX9/DX10 mode that essentially fuses the conventional DX9 path with DX10 water ripples.

In Part 2 we then took a look at BioShock’s performance with today’s latest mainstream graphics cards. We found that cards like the GeForce 8600 GTS could deliver decent frame rates with the game under high quality settings provided the resolution wasn’t too high. On the graphics front, dropping down to medium quality provided a nice performance boost without impacting image quality too much (i.e. the game didn’t become an ugly mess), while the Radeon HD 2600 XT card delivered very impressive performance results under DX9 mode. The game also runs quite well on older hardware like the Radeon X1950 Pro.

Based on all this, it looks like you don’t have to shell out the cash for a GeForce 8800 or Radeon HD 2900 XT if you’re on a tight budget. But what if you want to play the game with AA? That’s what we’re here today to examine.

As it stands now, AA only works in BioShock’s DX9 mode, and only with GeForce hardware. We tried forcing AA with the Radeon HD 2900 XT under both Windows Vista and WinXP with all four custom filter AA modes (including edge detect) and couldn’t get AA to work properly in BioShock. We asked AMD if they plan on adding AA support to BioShock in a future Catalyst driver revision but couldn’t get a direct answer. The only way to enable AA under BioShock with Radeon cards is to rename the BioShock executable from “bioshock.exe” to “Oblivion.exe”. Keep in mind by doing this though, AMD’s driver-level optimizations for the game are automatically disabled, and as a result, performance suffers – we recorded a frame rate of just 26.7 fps for the 2900 XT with the executable renamed to Oblivion.exe running our manual walkthrough sequence under 4xAA at 1600x1200. (Surprisingly enough, the Radeon X1950 Pro delivered a frame rate of 20.9 fps under the exact same scenario) Because of this, AMD’s Dave Baumann told us flat out not to run the game with the renamed executable.

In order to enable AA for GeForce cards you have to use the driver control panel, and as we mentioned previously it only works under the game’s pure DX9 codepath. Neither the hybrid path nor the DX10 path can be run with AA, although NVIDIA is working on integrating AA support into DX10 for a future driver release.