ATI Radeon HD 2600 XT

The ATI Radeon HD 2600 XT (Mac Edition) was a mid-range graphics card marketed by Advanced Micro Devices (AMD) and released by Apple on January 8, 2008 as the entry-level option for the 2008 1st-generation Mac Pros. It is based on a GPU chipset originally developed by ATI Technologies (which was acquired by AMD). It was also sold separately and was backward compatible with the 2006 1st-generation Mac Pro.

Description
The Radeon HD 2600 XT Mac Edition is based on ATI's RV630 graphics chip that was fabricated by TSMC on the 65 nm process. The GPU clock speed was 700 MHz, which could be boosted to 800 MHz, producing up to 168.0 gigaflops. It contained 256 MB of GDDR3 video RAM. The card features two dual-link DVI ports capable of driving up to two digital displays at 2560 x 1600 pixels, such as the 30-inch Apple Cinema HD Display. With DVI to VGA Adapters, up to two analog (VGA) displays could be supported at up to 2048 x 1536 pixels. It took up the space of a single PCIe 1.0 x16 slot, and needed no additional power cables. Though its peak performance was was below that of the preceding ATI Radeon X1900 XT, its power consumption was reduced to less than half.

Support
The Radeon HD 2600 XT Mac Edition requires a minimum of Mac OS X 10.5.2 (Leopard) or later. The Leopard Graphics Update is also recommended and a firmware update for the card was released on March 10, 2008 Some Mac Pros running Mac OS X 10.6.4 required a Snow Leopard Graphics Update for improved stability, which was incorporated into Mac OS X 10.6.5 and later. The card was supported through macOS 10.13.6 (High Sierra). However, it does not support Metal, and as a result will not work with macOS Mojave (10.14) or later.