ATI Radeon HD 2600 XT Mac Edition

The ATI Radeon HD 2600 XT Mac Edition is an AMD graphics card built on the RV630 chip, employing the TeraScale architecture. Fabricated on a 65 nm process at TSMC, the card integrates 390 million transistors into a 153 mm² die, yielding a transistor density of 2.5M / mm². Released on 2008-02-20, this single-slot card sits at the 50th percentile of all GPUs tracked in the benchmark database, with an aggregate benchmark score of 0, indicating a median historical position.

Benchmark Performance

The data shows a raw FP32 throughput of 168.0 GFLOPS, derived from 120 shading units. The pixel rate is 2.800 GPixel/s, while the texture rate is 5.600 GTexel/s, produced by 8 TMUs and 4 ROPs. With an average benchmark score of 0, the card's absolute performance is unremarkable, but its 50th percentile ranking places it exactly at the median of all GPUs ever tracked. Without nearestRivals data, exact percentage deltas cannot be computed, but the raw figures position it firmly in the entry-level segment of its 2008 era. The 168.0 GFLOPS compute capability allows for basic DirectX 10.0 workloads, but modern games with heavy shader complexity will exceed its limits. The 2.800 GPixel/s fill rate is sufficient for 720p resolutions at moderate settings, yet it will choke at 1080p with any anti-aliasing. The 5.600 GTexel/s texture rate indicates a bottleneck in texture-dense scenes, a common trait of the 65 nm mid-range parts. The 4 ROPs further limit pixel throughput, making the card best suited for older titles or 2D desktop work. The 50th percentile ranking is a double-edged sword: it outperforms half of all historical GPUs, but that also means half outperform it, placing it in the middle of the pack. The 168.0 GFLOPS figure, when divided across 120 shading units, reveals a per-unit throughput that was typical for the TeraScale generation, though it lacks the raw parallel power of later architectures. The 2.800 GPixel/s and 5.600 GTexel/s rates are closely matched, suggesting a balanced design for its era, but the low ROP count caps its ability to handle high-resolution framebuffers.

Power and Cooling

The card has a TDP of 45 W, making it exceptionally power-efficient. The suggested PSU is 200 W, and it requires no auxiliary power connectors, drawing all power from the PCIe 1.0 x16 slot. Its single-slot design ensures easy installation in compact Mac systems. The 45 W thermal envelope means a simple air cooler is sufficient, and the card ships with a capable air cooler that maintains quiet operation. Because no power connectors are needed, cable management is trivial, and the 200 W PSU recommendation is conservative, allowing it to work in older Mac Pro towers with modest power supplies. The absence of a 6-pin or 8-pin connector reduces the risk of power delivery issues in aging systems. The single-slot form factor is a significant advantage for Mac users with limited expansion slots, as it leaves adjacent slots free for other PCIe cards. The 45 W TDP is a fraction of what contemporary high-end cards demanded, making this an ideal drop-in upgrade for systems with weak power supplies. The 200 W suggested PSU is a low bar, and the card's power draw is low enough that it can run passively in some chassis, though the stock cooler is active.

Ray Tracing and Feature Set

This card lacks dedicated RT cores and tensor cores, as indicated by the null values in the FACT PACK. Consequently, hardware ray tracing is not supported. The API support includes DirectX 10.0 (10_0) and OpenGL 3.3, with no Vulkan support. DirectX 10.0 introduced the unified shader model, which the TeraScale architecture leverages across its 120 shading units. OpenGL 3.3 provides compatibility with a wide range of applications, though it lacks modern features like compute shaders and tessellation. The absence of Vulkan means no access to low-overhead graphics APIs. For a Mac Edition card, the 2x DVI outputs are the only display connectivity, limiting multi-monitor setups to two DVI displays. The TeraScale architecture itself is a unified shader design, but without tensor or RT cores, machine learning and ray tracing workloads are entirely out of scope. The DirectX 10.0 feature level (10_0) was a major step at the time, enabling geometry shaders and stream output, but it has long been superseded. The OpenGL 3.3 support is notably more modern than the DirectX 10.0 level, allowing the card to run certain OpenGL applications that would otherwise be incompatible. The lack of Vulkan is a clear generational limitation, as even the successor Radeon R700 would eventually support it, but this card is firmly anchored to its 2008 release window.

How It Compares

The nearestRivals list is empty in the FACT PACK, so direct competitor comparisons cannot be made. However, the data provides context through its predecessor and successor. The predecessor, Radeon R500 PCIe, was a fixed-function pipeline design. The HD 2600 XT Mac Edition's unified shader architecture with 120 shading units and 168.0 GFLOPS FP32 represents a fundamental generational shift. DirectX 10.0 support, which the R500 lacks, is a major advantage. The 45 W TDP is a significant efficiency improvement over older parts, and the 25.60 GB/s bandwidth is a step up.

The successor, Radeon R700, would later bring higher transistor counts and improved tessellation, but the HD 2600 XT's 50th percentile ranking shows it held its own for a time. The R700 would likely double the ROP count and memory bus width, but the HD 2600 XT's 4 ROPs and 128-bit bus are adequate for its intended 720p use case. The 200 W PSU suggestion is lower than what the R700 would require, making the HD 2600 XT a more accessible upgrade for older Macs.

The overall percentile standing of 50th across all GPUs means it sits at the median of the entire historical database. This is a neutral position, indicating that while it is not a high-end part, it is not a bottom-tier one either. The average benchmark score of 0 reinforces that it is a baseline performer. For a Mac Edition card, this median standing is acceptable, as its primary role was to enable basic 3D acceleration and dual DVI output for professional Mac users.

Memory Subsystem

The memory subsystem consists of 256 MB of GDDR3 memory on a 128-bit bus, running at 800 MHz with an effective data rate of 1600 Mbps. This yields a bandwidth of 25.60 GB/s. For a card from 2008, 256 MB was a common capacity for entry-level and mid-range parts, but it is a limiting factor at high resolutions. At 1080p or above, the 256 MB frame buffer will overflow with modern textures, forcing the card to swap to system memory over the PCIe 1.0 x16 interface, which has limited bandwidth. The 128-bit bus width is a bottleneck for memory-intensive operations, as the 25.60 GB/s bandwidth is roughly half of what higher-end cards of the same generation offered. The effective 1600 Mbps data rate is standard for GDDR3, but the narrow bus constrains overall throughput. For 720p gaming or 2D desktop work, the memory subsystem is adequate, but for 3D applications at 1920x1080, the card will likely struggle with texture thrashing. The 2.800 GPixel/s pixel rate, combined with 25.60 GB/s bandwidth, means that fill-rate-limited scenarios will be more manageable than bandwidth-limited ones, but both are modest. The 4 ROPs further limit the pixel output, making high-resolution anti-aliasing impractical. In summary, the memory subsystem is the primary constraint on the HD 2600 XT Mac Edition's longevity, as the 256 MB capacity and 128-bit bus are insufficient for modern workloads. The 25.60 GB/s bandwidth is a clear indicator of its entry-level positioning within the Radeon R600 generation.