AMD has posted the latest version of its Catalyst driver package for ATI-branded graphics chips. The Windows Vista and XP release enhances games' scope to overclock Radeon HD 2400 and 2600 series GPUs. It also patches the Purple Pill vulnerability.

Catalyst 7.8 lets owners of these graphics chips overclock both the GPU's core frequency and connected graphics memory in single-chip and dual-chip Crossfire configurations, AMD said. The package also includes a utility to verify that a given graphics chip will operate at the chosen overclocked settings.

Other tweaks include performance boosts for DirectX 10 game Lost Planet, along with frame rate improvements for Serious Sam 2 - with high dynamic range (HDR) rendering enabled. Benchmarks 3DMark05 and 3DMark06 should show higher scores after the new drivers are installed.

AMD recommends everyone install Catalyst 7.8 to block the Purple Pill security flaw - named after the proof-of-concept tool written to highlight the glitch. Purple Pill created an easy way to load and unload unsigned and potentially malicious drivers on Vista. The utility circumvented new anti-rootkit defences built into Vista by turning off checks for signed drivers.

The Linux version of Catalyst 7.8 - release 8.40.4 - incorporates the addition of TV-out to the Catalyst Control Center app, along with a 64-bit version of the utility. A number of bugs have been stomped too.

Full details of both versions of the update and the downloads themselves can be found at the ATI website.