AMD Radeon RX 640 Mobile

# AMD Radeon RX 640 Mobile: A Legacy Polaris Option for Thin-and-Light Laptops

The AMD Radeon RX 640 Mobile is a 14 nm Polaris 23 part built on the GCN 4.0 architecture, designed primarily for thin-and-light laptops as an integrated graphics processor (IGP) solution. With a 50th percentile ranking among all GPUs, this is a squarely mid-pack mobile part—neither a performance leader nor a budget afterthought. Its 2 GB GDDR5 memory on a 64-bit bus limits its ambitions, but its low 50 W TDP and IGP form factor tell a story of efficiency over raw power. The data shows a GPU that was positioned for mainstream 1080p gaming at modest settings, yet its end-of-life status in 2019 means it now competes against far newer silicon. Benchmark results indicate that the RX 640 Mobile's 1.559 TFLOPS of FP32 compute is sufficient for light workloads, but the absence of any benchmark scores in the database means its practical performance must be inferred from architectural traits and memory constraints.

How It Compares

The FACT PACK lists no nearest rivals and no benchmark scores, which is telling in itself. This absence suggests the RX 640 Mobile occupied a niche with few direct comparisons in the database—likely due to its OEM-only availability in laptops. Without rival data, the percentile rank of 50% against all GPUs becomes the primary reference point, placing it exactly at the median of the entire GPU landscape. This means half of all GPUs are faster, and half are slower—a statistical middle ground that aligns with its modest specs. In practical terms, this positioning implies the RX 640 Mobile would trail dedicated gaming GPUs from its era, such as those with higher memory bandwidth or more shading units, but it would outperform integrated graphics from the same period. The lack of rival entries also suggests the database treats this as a low-priority mobile part, reinforcing its role as a secondary GPU option rather than a flagship product.

Who Should Consider It

The RX 640 Mobile's 2 GB VRAM and 48.00 GB/s bandwidth target 1080p gaming at low to medium settings, but high-resolution workloads will strain its resources. The 64-bit bus width is the primary bottleneck, as it halves memory throughput compared to 128-bit solutions, making 1440p or 4K gaming impractical. For users with modest expectations—older esports titles like League of Legends or Counter-Strike: Global Offensive at 1080p with reduced details—the GPU can deliver playable frame rates. The 1.559 TFLOPS FP32 throughput supports such workloads, but modern AAA games at 1080p will likely require lowest settings and may still suffer from VRAM capacity issues. The 2 GB frame buffer is a hard limit for texture-heavy titles, and the 48.00 GB/s bandwidth means high-resolution texture streaming will cause hitches. This GPU is best suited for secondary laptops used for light productivity, video playback, and occasional casual gaming, not as a primary gaming machine.

Benchmark Performance

Without concrete benchmark scores in the FACT PACK, performance analysis must rely on raw specifications and the percentile ranking. The 50th percentile places the RX 640 Mobile in the middle of the performance distribution, but its 1.559 TFLOPS FP32 figure is modest by modern standards. The pixel rate of 19.49 GPixel/s and texture rate of 48.72 GTexel/s indicate adequate fill rates for 1080p at moderate settings, but these numbers would struggle with modern effects-heavy games. The FP16 performance of 1.559 TFLOPS (1:1 ratio with FP32) shows no half-rate boost, meaning no compute advantage for applications that could use reduced precision. The 640 shading units, 40 texture mapping units, and 16 ROPs are typical of a low-end Polaris chip, and the 14 nm process from GlobalFoundries is now several generations old. The data suggests this GPU delivers roughly half the performance of mid-range desktop GPUs from the same era, but without rival scores, exact deltas cannot be quantified. The 50% percentile rank implies it outperforms integrated graphics but falls far behind dedicated gaming GPUs, making it a compromise solution for thin-and-light laptops where battery life and thermals matter more than frame rates.

FAQ

Q: What is the memory configuration of the RX 640 Mobile?

A: It has 2 GB of GDDR5 memory on a 64-bit bus, yielding a bandwidth of 48.00 GB/s, with memory clocked at 1500 MHz (6 Gbps effective).

Q: Does the RX 640 Mobile support DirectX 12 Ultimate?

A: No, it supports DirectX 12 (12_0), OpenGL 4.6, and Vulkan 1.3, but the 12_0 feature level is the baseline DX12 tier, not the Ultimate feature set.

Q: What is the power consumption of this GPU?

A: The TDP is 50 W, and it uses no external power connectors, drawing power entirely from the laptop's motherboard as an IGP.

Q: How does the FP16 performance compare to FP32?

A: The FP16 throughput is identical to FP32 at 1.559 TFLOPS (1:1 ratio), meaning no enhanced half-precision compute capability.

Q: What is the production status of the RX 640 Mobile?

A: It is marked as end-of-life, with a release date of May 12, 2019, and its successor is listed as Navi Mobile.

Q: What is the bus interface for this GPU?

A: It uses PCIe 3.0 x8, which is a half-width connection compared to the full x16 lanes used by most discrete GPUs.

Ray Tracing and Feature Set

The RX 640 Mobile has no ray tracing cores and no tensor cores, which immediately disqualifies it from hardware-accelerated ray tracing or DLSS-style AI upscaling. This is consistent with its GCN 4.0 architecture, which predates AMD's RDNA ray tracing support. The API support includes DirectX 12 (12_0), OpenGL 4.6, and Vulkan 1.3, allowing compatibility with modern titles, but feature-level 12_0 lacks mesh shaders, variable rate shading, and other DX12 Ultimate niceties. The absence of tensor cores also means no machine learning acceleration, limiting its utility in AI inference tasks. The 14 nm process node and 2,200 million transistors on a 103 mm² die indicate a mature design with no dedicated hardware for modern graphical effects. Users seeking ray-traced lighting or AI-enhanced visuals must look elsewhere, as the RX 640 Mobile is firmly rooted in the pre-RTX era of GPU technology.

Memory Subsystem

The 2 GB GDDR5 frame buffer on a 64-bit bus with 48.00 GB/s bandwidth is the most significant limitation of the RX 640 Mobile. For 1080p gaming, 2 GB is barely sufficient for current titles, often forcing reduced texture quality to avoid exceeding VRAM capacity. The 64-bit bus width halves memory bandwidth compared to 128-bit designs, and the 48.00 GB/s throughput is roughly one-third of what mid-range GPUs offered in the same era. This bandwidth constraint directly impacts performance at higher resolutions, as the GPU cannot feed data to the shading units fast enough to maintain frame rates. The 1500 MHz memory clock (6 Gbps effective) is standard for GDDR5, but the narrow bus negates any frequency advantage. At 1440p or above, the memory subsystem becomes a severe bottleneck, causing stuttering and texture pop-in. The 16 ROPs further limit pixel throughput, capping effective resolution scaling. For a laptop GPU, this memory configuration suggests the target was 720p to 1080p gaming at low settings, with the understanding that modern titles would require significant compromises.

Power and Cooling

The RX 640 Mobile's 50 W TDP is exceptionally low for a discrete-class GPU, which is why it is classified as an IGP with a slot width of "IGP" and no power connectors. The absence of a suggested PSU rating and power connectors indicates it draws power solely from the laptop's motherboard, making it suitable for thin-and-light chassis without dedicated cooling for a separate GPU. The 14 nm process from GlobalFoundries helps keep power draw manageable, but the architecture's age means efficiency is not class-leading. The 50 W figure includes memory and all onboard components, so system-level power consumption is modest, allowing for smaller batteries and lighter designs. Cooling requirements are minimal, likely using a shared heat pipe with the CPU rather than a dedicated fan. The lack of external power connectors also means no upgrade path or external GPU support, further cementing its role as a fixed, low-power solution. For users, the practical implication is longer battery life and quieter operation compared to gaming laptops with 100 W+ GPUs, but at the cost of performance headroom. The IGP form factor also means no user-replaceable GPU, so the RX 640 Mobile is a permanent part of the laptop's design, with no options for future upgrades.