ATI Mobility Radeon HD 3870 X2

The ATI Mobility Radeon HD 3870 X2 is a mobile graphics processor from AMD, built on the TeraScale architecture and fabricated at TSMC using a 55 nm process. It integrates 666 million transistors on a 192 mm² die, with a transistor density of 3.5 million per square millimeter. Released in August 2008, it belongs to the M8x generation of Mobility HD 3800 series, positioned between the M7x and M9x predecessors and successors. The GPU is now end-of-life, and its benchmark database entry shows a percentile rank of 50 among all GPUs, with an average benchmark score of zero, indicating that no representative performance measurements have been recorded.

Benchmark Performance

The benchmark data for this GPU is notably sparse. The percentileVsAllGpus field reports a value of 50, placing it exactly at the median of the entire GPU database. This suggests that, in the absence of direct benchmark scores, the hardware occupies a middle ground relative to all other GPUs cataloged. The average benchmark score is listed as zero, which likely reflects the absence of any submitted performance runs rather than a literal zero performance. Consequently, any interpretation of its computational capability must rely on its architectural specifications rather than measured results.

The raw compute throughput is quantified by an FP32 rating of 422.4 GFLOPS, a figure derived from its 320 shading units operating at the given clock frequencies. This level of single-precision performance is modest by modern standards but was competitive for a mobile part in its era. The pixel fill rate and texture fill rate are both 10.56 GPixel/s and 10.56 GTexel/s, respectively, matching the 16 ROPs and 16 TMUs. This balance indicates that the GPU can sustain similar throughput for pixel and texture operations, which is typical for a TeraScale design. The lack of any benchmark scores means we cannot directly compare it to specific rivals, but the 50th percentile suggests it sits at the midpoint of the performance distribution—neither a standout nor a laggard.

Ray Tracing and Feature Set

The ATI Mobility Radeon HD 3870 X2 does not include any dedicated ray tracing cores or tensor cores, as these fields are null in the specification. This is consistent with its TeraScale architecture, which predates hardware-accelerated ray tracing by over a decade. The GPU supports DirectX 10.1 (shader model 10_1) and OpenGL 3.3, but it has no Vulkan support. This API set limits the GPU to games and applications that were developed for the DirectX 10.1 or OpenGL 3.3 era, roughly the late 2000s. There is no mention of hardware-accelerated AI features, as tensor cores are absent, so any machine learning workloads would rely on the general-purpose FP32 compute.

The absence of modern feature sets means that the GPU cannot leverage contemporary rendering techniques such as real-time ray tracing or DLSS-style upscaling. For a user of this hardware, the practical implication is that they would be restricted to older titles that were built around DirectX 10.1 or earlier. The lack of Vulkan support further narrows compatibility with modern open-standard engines. The display outputs are described as "Portable Device Dependent," meaning the actual connectors and supported resolutions are dictated by the laptop or mobile platform rather than being fixed by the GPU itself.

Power and Cooling

The thermal design power (TDP) of this GPU is specified at 110 W. This is a significant power draw for a mobile component, especially considering the 55 nm process node. The high TDP implies that a laptop or portable device incorporating this GPU would require a robust cooling solution to manage heat dissipation. The fact pack does not list a suggested PSU or power connector requirements, so we cannot state any specific wattage for the power supply. However, the 110 W figure alone suggests that the system would need a substantial battery and thermal design.

The bus interface is PCIe 2.0 x16, which was standard for discrete mobile GPUs of that period. The absence of a power connector specification suggests that power is delivered through the motherboard connector, typical for mobile platforms. Given the 110 W TDP, the device would likely run hot under load, and the cooling solution would be a critical factor in sustained performance. The lack of a slot width or dimension data indicates that this is a chip-level component, not a full expansion card.

How It Compares

The nearestRivals array in the fact pack is empty, meaning the benchmark database provides no direct competitor names, scores, or deltaPct values for this GPU. Therefore, we cannot perform a head-to-head comparison against specific rival products. What we do have is the overall percentile rank of 50, which places this GPU at the median of all GPUs in the database. This suggests that, on a purely relative scale, it performs at the level of the typical GPU—neither above nor below the average.

In the absence of rival data, we can only contextualize its position through its architectural lineage. It sits between the M7x and M9x generations, but no performance metrics for those predecessors or successors are provided. The lack of any benchmark scores or rival comparisons means that any attempt to quantify its standing relative to other mobile GPUs of its time would be speculative. The data simply shows that it is an average performer within the entire GPU spectrum, as indicated by the 50th percentile.

Who Should Consider It

Given the specifications and the absence of benchmark scores, the ATI Mobility Radeon HD 3870 X2 is best suited for users who require a GPU for legacy applications. Its 512 MB of GDDR3 memory and 54.40 GB/s bandwidth are adequate for 720p or lower resolutions, though we cannot specify exact resolution figures as they are not in the fact pack. The FP32 throughput of 422.4 GFLOPS and the 10.56 GPixel/s fill rate suggest it can handle older DirectX 10.1 games at modest settings. However, the 110 W TDP makes it impractical for thin-and-light notebooks; it would be found in larger, gaming-oriented laptops of the late 2000s.

The GPU supports DirectX 10.1 and OpenGL 3.3, so it can run games that use those APIs. It cannot run modern titles that require DirectX 12 or Vulkan, and it lacks any ray tracing capability. Therefore, a user would need to accept a limited software ecosystem. The lack of benchmark data means we cannot give performance expectations in frames per second, but the raw compute numbers indicate that it is not suitable for high-end gaming or compute-intensive tasks. It might be used for basic productivity, older games, or as a secondary display adapter in a portable device.

FAQ

Q: Does the ATI Mobility Radeon HD 3870 X2 support ray tracing?

A: No. The GPU has no ray tracing cores (RT cores are null), and its TeraScale architecture predates hardware ray tracing. It only supports DirectX 10.1 and OpenGL 3.3.

Q: What is the memory size and type?

A: It has 512 MB of GDDR3 memory, with a 256-bit bus width and a bandwidth of 54.40 GB/s.

Q: What is the thermal design power (TDP)?

A: The TDP is 110 W, which is relatively high for a mobile GPU, indicating the need for substantial cooling.

Q: Is there any Vulkan support?

A: No. The API list includes DirectX 10.1 and OpenGL 3.3, but Vulkan is not supported (null value).

Q: What is the transistor count and die size?

A: It contains 666 million transistors on a 192 mm² die, manufactured on a 55 nm process.

Q: What is the average benchmark score for this GPU?

A: The average benchmark score is 0, and the percentile rank is 50, meaning it sits at the median of all GPUs but no actual performance scores are recorded.

Memory Subsystem

The memory subsystem of the ATI Mobility Radeon HD 3870 X2 is defined by 512 MB of GDDR3 memory, a 256-bit memory bus, and a bandwidth of 54.40 GB/s. The memory clock is 850 MHz, with an effective data rate of 1700 Mbps (double data rate). This configuration was typical for high-end mobile GPUs in 2008, though the capacity of 512 MB is limited by today's standards. The 256-bit bus width is relatively wide, which helps achieve the 54.40 GB/s bandwidth—a figure that is moderate but sufficient for the pixel and texture fill rates of 10.56 GPixel/s and 10.56 GTexel/s.

At high resolutions, the 512 MB VRAM could become a bottleneck because modern textures and frame buffers can exceed that capacity. The bandwidth of 54.40 GB/s is also modest compared to later GDDR5 and GDDR6 solutions. For the era, this memory configuration allowed the GPU to handle 720p gaming with moderate detail, but it would struggle with higher resolutions or heavy anti-aliasing. The absence of any memory overclocking or additional specifications means we cannot infer any headroom. The memory subsystem is a balanced match to the GPU's compute capabilities, but its small capacity and limited bandwidth restrict its utility in demanding scenarios.