AMD Radeon Instinct MI25 vs NVIDIA RTX A4500 Mobile Comparison

# NVIDIA RTX A4500 Mobile vs AMD Radeon Instinct MI25

The NVIDIA RTX A4500 Mobile and AMD Radeon Instinct MI25 represent two very different eras of GPU design, and the benchmark data reflects that gap clearly. The RTX A4500 Mobile scores 105,307 in Geekbench OpenCL, a 53.6% advantage over the MI25's 68,562. The A4500 Mobile places in the 93rd percentile of all GPUs, while the MI25 sits at the 90th percentile, but the raw score difference is substantial. For anyone choosing between these two end-of-life products, the RTX A4500 Mobile is the stronger compute performer, though the MI25 has its own niche for specific workloads.

The Verdict

The data points to a clear winner for general compute: the NVIDIA RTX A4500 Mobile. Its Geekbench OpenCL score of 105,307 versus 68,562 for the AMD Radeon Instinct MI25 represents a 53.6% performance lead in that test. The A4500 Mobile's average benchmark score of 91,134 also dwarfs the MI25's 68,562 average. However, the decision isn't purely about raw numbers. The A4500 Mobile is a mobile GPU with a 140 W TDP and no power connectors, designed for portable workstations, while the MI25 is a 300 W dual-slot accelerator requiring 2x 8-pin power connectors and a 700 W suggested PSU. The MI25 has no display outputs, making it strictly a compute device, whereas the A4500 Mobile's display outputs are portable-device dependent. For users needing a self-contained mobile workstation GPU, the A4500 Mobile is the only real option. For fixed installations where power and space are not constraints, the MI25's lower FP32 throughput (12.29 TFLOPS vs 17.66 TFLOPS) still makes it the weaker compute choice, despite its higher FP16 capability (24.58 TFLOPS vs 17.66 TFLOPS). The verdict: the RTX A4500 Mobile wins on performance and versatility, while the MI25 only makes sense if you specifically need its 2:1 FP16 ratio or already have the infrastructure for a 300 W accelerator.

Architecture Differences

The architectural gap between these two GPUs spans nearly five years of design evolution. The NVIDIA RTX A4500 Mobile uses the GA104 chip built on Samsung's 8 nm process, housing 17,400 million transistors on a 392 mm² die, yielding a transistor density of 44.4 million per mm². The AMD Radeon Instinct MI25 uses the Vega 10 chip on GlobalFoundries' 14 nm process, with 12,500 million transistors on a larger 495 mm² die, giving a density of just 25.3 million per mm². This density advantage translates directly into the A4500 Mobile's feature set. The NVIDIA part has 5,888 shading units, 184 texture mapping units, and 96 ROPs, while the MI25 has 4,096 shading units, 256 TMUs, and 64 ROPs. The A4500 Mobile also brings dedicated ray tracing cores (46) and tensor cores (184), neither of which exist on the MI25, since it predates those technologies. API support differs too: the A4500 Mobile supports DirectX 12 Ultimate (12_2) and Vulkan 1.4, while the MI25 tops out at DirectX 12 (12_1) and Vulkan 1.3. Memory architecture is another major divergence. The A4500 Mobile uses 16 GB of GDDR6 on a 256-bit bus, delivering 512.0 GB/s of bandwidth. The MI25 also has 16 GB, but it's HBM2 on a massive 2048-bit bus, providing 436.2 GB/s. Despite the much wider bus, the MI25's lower memory clock (852 MHz base, 1704 Mbps effective) results in less bandwidth than the A4500 Mobile's 2000 MHz GDDR6 (16 Gbps effective). The A4500 Mobile's pixel rate is 144.0 GPixel/s versus 96.00 GPixel/s for the MI25, but the MI25 wins on texture rate: 384.0 GTexel/s versus 276.0 GTexel/s for the NVIDIA part, a consequence of having 256 TMUs versus 184.

Head-to-Head Benchmarks

The sole head-to-head benchmark available is Geekbench OpenCL, and it's not close. The NVIDIA RTX A4500 Mobile scores 105,307, while the AMD Radeon Instinct MI25 scores 68,562, giving the A4500 Mobile a 53.6% victory. This result aligns with the FP32 compute figures: the A4500 Mobile delivers 17.66 TFLOPS versus 12.29 TFLOPS for the MI25. The MI25 does have a counterargument in FP16 workloads, where its 24.58 TFLOPS (at 2:1 ratio) beats the A4500 Mobile's 17.66 TFLOPS (at 1:1 ratio), but this advantage doesn't show up in the OpenCL benchmark. Looking at the rival context, the A4500 Mobile's nearest competitors include the desktop NVIDIA RTX A4500 (average score 91,671, just 0.6% behind), the AMD Radeon Instinct MI60 (92,466, 1.4% behind), and it leads the NVIDIA Quadro GP100 by 4.2% and the AMD Radeon PRO W7600 by 4.6%. The MI25's nearest rivals are much closer: the Intel Arc A770 (68,809, just 0.4% ahead), NVIDIA CMP 90HX (69,000, 0.6% ahead), AMD Radeon Pro WX 8200 (69,870, 1.9% ahead), and NVIDIA Quadro P6000 (69,986, 2% ahead). This suggests the MI25 sits near the bottom of its performance class, while the A4500 Mobile sits near the top of its own tier.

FAQ

Q: Which GPU has higher raw compute performance in FP32?

A: The NVIDIA RTX A4500 Mobile delivers 17.66 TFLOPS FP32, which is 43.7% higher than the AMD Radeon Instinct MI25's 12.29 TFLOPS.

Q: Does the AMD MI25 have any advantage in compute workloads?

A: Yes, the MI25 offers 24.58 TFLOPS FP16 performance at a 2:1 ratio, which exceeds the A4500 Mobile's 17.66 TFLOPS FP16 at a 1:1 ratio, making it potentially faster for workloads that exploit FP16.

Q: How do their memory bandwidths compare?

A: The A4500 Mobile has 512.0 GB/s of bandwidth from 16 GB of GDDR6 on a 256-bit bus, while the MI25 has 436.2 GB/s from 16 GB of HBM2 on a 2048-bit bus.

Q: Which GPU is more power-efficient?

A: The A4500 Mobile has a 140 W TDP and requires no power connectors, while the MI25 has a 300 W TDP and needs 2x 8-pin power connectors with a 700 W suggested PSU, indicating the A4500 Mobile consumes less than half the power.

Q: Can either GPU be used for display output?

A: The A4500 Mobile's display outputs are portable-device dependent, meaning it can drive displays in a mobile workstation context. The MI25 has no display outputs at all and is compute-only.

Q: What are their API compatibility levels?

A: The A4500 Mobile supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. The MI25 supports DirectX 12 (12_1), OpenGL 4.6, and Vulkan 1.3.

Where Each One Wins

The NVIDIA RTX A4500 Mobile wins in every measured benchmark category and in most architectural comparisons. It's 53.6% ahead in Geekbench OpenCL, has 43.7% more FP32 throughput, 17.4% more memory bandwidth, and a 50% higher pixel rate (144.0 vs 96.00 GPixel/s). Its 8 nm process with 44.4M transistors per mm² gives it a density advantage that enables features the MI25 lacks entirely: 46 ray tracing cores and 184 tensor cores. The A4500 Mobile also supports newer API versions across the board. For anyone doing general-purpose GPU compute, machine learning inference (thanks to tensor cores), or any ray-traced workload, the A4500 Mobile is the clear choice. Its mobile form factor with 140 W TDP and no external power connectors makes it practical for laptop workstations. The MI25's wins are narrower but real. Its texture rate of 384.0 GTexel/s is 39.1% higher than the A4500 Mobile's 276.0 GTexel/s, thanks to 256 TMUs versus 184. Its FP16 performance at 24.58 TFLOPS is 39.2% higher than the A4500 Mobile's 17.66 TFLOPS, though only for workloads that can exploit the 2:1 ratio. The MI25's 2048-bit HBM2 bus is also a unique trait, even if the resulting bandwidth is lower. For fixed rack-mounted compute nodes where power and cooling are available, the MI25 could still serve for FP16-heavy scientific workloads, but its lack of display outputs and older architecture limit its appeal. The data shows one clear winner for most use cases, but the MI25 retains niche value for texture-bound and FP16-specific tasks.