AMD Radeon R5 M230 vs NVIDIA GeForce GT 645M Comparison

The AMD Radeon R5 M230 and NVIDIA GeForce GT 645M are both end-of-life mobile graphics solutions from different architectural generations, yet benchmark data reveals a clear performance gap. In the sole head-to-head benchmark, the AMD part delivers a 70.8% higher OpenCL score than the NVIDIA part, though both sit in the bottom quartile of all GPUs, with percentiles of 27 and 26 respectively.

The Verdict

From the data, the AMD Radeon R5 M230 is the outright performance winner in compute workloads. Its Geekbench OpenCL score of 4577 crushes the GeForce GT 645M's 2680, a 70.8% advantage that is decisive for any OpenCL-accelerated task. The GT 645M, however, is no slouch in other API tests, posting a Geekbench Metal score of 5679 and a Vulkan score of 4875, though these have no direct AMD counterpart in the data.

The AMD part's average benchmark score of 4577 places it in a tight cluster with the AMD Radeon RX 560 (4569, 0.2% behind) and Intel HD Graphics P530 (4560, 0.4% behind), while slightly trailing the NVIDIA Quadro M3000M (4621, -0.9%) and GeForce GTX 970M (4628, -1.1%). The GT 645M's average of 4411 sits near the NVIDIA GeForce 930M (4388, 0.5% behind) and Intel Iris Pro Graphics 5200 (4360, 1.2% behind), while ahead of the NVIDIA GeForce RTX 4070 GDDR6 (4335, 1.8% ahead) and behind the AMD Radeon R7 M260 (4499, -1.9%).

For users choosing between these two, the R5 M230 is the logical pick for raw compute performance and OpenCL workloads. The GT 645M offers broader API coverage with Metal and Vulkan support, which may matter for specific applications, but its substantially lower OpenCL score makes it the weaker all-around choice in this comparison.

Architecture Differences

The two GPUs come from rival architectures and different process generations. The AMD Radeon R5 M230 uses the Jet chip built on GCN 1.0 architecture, fabricated by TSMC on a 28 nm process. It packs 690 million transistors into a 56 mm² die, yielding a transistor density of 12.3M per mm². The NVIDIA GeForce GT 645M uses the GK107 chip based on Kepler architecture, also on TSMC's 28 nm node, but with 1,270 million transistors spread across a much larger 118 mm² die, giving a lower density of 10.8M per mm².

The NVIDIA chip's larger transistor budget translates into a more robust compute configuration. The GT 645M features 384 shading units, 32 texture mapping units, and 16 ROPs, compared to the R5 M230's 320 shading units, 20 TMUs, and 8 ROPs. This hardware disparity shows up in theoretical rates: the GT 645M delivers 599.0 GFLOPS FP32, 24.96 GTexel/s texture fill, and 6.240 GPixel/s pixel fill, versus the R5 M230's 390.4 GFLOPS, 12.20 GTexel/s, and 4.880 GPixel/s.

Memory configurations differ significantly. Both cards have 2 GB of DDR3 memory, but the GT 645M uses a 128-bit bus, delivering 28.80 GB/s bandwidth, while the R5 M230 is limited to a 64-bit bus for 16.00 GB/s. Memory clocks also favor NVIDIA: 900 MHz (1800 Mbps effective) versus AMD's 1000 MHz (2 Gbps effective). The NVIDIA card has base and boost clocks of 709 MHz and 780 MHz, while the AMD card lists no base or boost clock, only its memory clock.

Other differences include the bus interface: the GT 645M uses PCIe 3.0 x16 versus the R5 M230's PCIe 3.0 x8. The NVIDIA card's TDP is 32 W, while the AMD card's TDP is not specified. API support shows the R5 M230 supports DirectX 12 (11_1) versus the GT 645M's DirectX 12 (11_0), but both support OpenGL 4.6 and Vulkan, with the GT 645M having a slightly newer Vulkan version (1.2.175 vs 1.2.170). The GT 645M also has a Metal benchmark result, indicating Apple API support. Both are IGP slot-width parts with portable-device-dependent display outputs.

Head-to-Head Benchmarks

The only direct comparison available is Geekbench OpenCL, and it is a landslide. The AMD Radeon R5 M230 scores 4577 against the GeForce GT 645M's 2680, a delta of 70.8% in AMD's favor. This is the single largest margin in either card's rival list, dwarfing the small percentage differences seen elsewhere.

For context, the R5 M230's OpenCL score is within 0.2% of the Radeon RX 560 and 0.4% of the Intel HD Graphics P530, and within 1.1% of the GeForce GTX 970M. The GT 645M's OpenCL performance, meanwhile, is far lower than its own average, suggesting this particular API is not its strength. Its other benchmark results — Metal at 5679 and Vulkan at 4875 — are substantially higher than its OpenCL number, indicating the card's compute performance is highly API-dependent.

The delta between the two cards in OpenCL is so large that it overshadows the GT 645M's theoretical hardware advantages. Despite having 20% more shading units, 60% more TMUs, double the ROPs, and 80% more memory bandwidth, the NVIDIA part cannot overcome the AMD architecture's efficiency in this workload. The 70.8% victory for AMD is a clear statement about GCN 1.0's OpenCL optimization relative to Kepler.

FAQ

Q: Which GPU has the higher average benchmark score?

A: The AMD Radeon R5 M230 has an average benchmark score of 4577, while the NVIDIA GeForce GT 645M averages 4411, a difference of roughly 3.8% in AMD's favor.

Q: What is the largest performance gap between these two cards?

A: In Geekbench OpenCL, the R5 M230 scores 4577 versus the GT 645M's 2680, a 70.8% delta that is the only head-to-head benchmark result in the data.

Q: Does the GeForce GT 645M support any APIs that the Radeon R5 M230 does not?

A: The GT 645M has a Geekbench Metal score of 5679, indicating Metal support, while the R5 M230 has no Metal benchmark listed. Both support DirectX 12, OpenGL 4.6, and Vulkan, though the R5 M230's DirectX version is 12 (11_1) versus the GT 645M's 12 (11_0).

Q: How do these cards compare to the NVIDIA GeForce RTX 4070 GDDR6?

A: The GT 645M's average score of 4411 is 1.8% higher than the RTX 4070 GDDR6's 4335, while the R5 M230's 4577 is not directly compared to that card in the rival data.

Q: Which card has more memory bandwidth?

A: The GeForce GT 645M has 28.80 GB/s bandwidth from a 128-bit bus, versus the R5 M230's 16.00 GB/s from a 64-bit bus, despite both using 2 GB of DDR3 memory.

Q: What are the transistor counts for each chip?

A: The GT 645M's GK107 chip contains 1,270 million transistors on a 118 mm² die, while the R5 M230's Jet chip contains 690 million transistors on a 56 mm² die.

Where Each One Wins

The AMD Radeon R5 M230 wins decisively in OpenCL compute performance. Its 4577 score versus the GT 645M's 2680 makes it the clear choice for any workload that leverages OpenCL, from general-purpose GPU computing to applications that offload parallel tasks. The R5 M230 also edges out the GT 645M in overall average benchmark score, 4577 to 4411, meaning it is the more consistent performer across the tests available in the data.

The NVIDIA GeForce GT 645M wins in raw hardware specifications and API breadth. It offers higher pixel rate (6.240 GPixel/s vs 4.880 GPixel/s), higher texture rate (24.96 GTexel/s vs 12.20 GTexel/s), and higher FP32 throughput (599.0 GFLOPS vs 390.4 GFLOPS). Its memory subsystem is superior, with double the bus width and 80% more bandwidth. The card also demonstrates strong performance in Metal (5679) and Vulkan (4875) benchmarks, suggesting it is better suited for applications that use those APIs.

For users prioritizing compute in OpenCL, the R5 M230 is the obvious winner. For those who need Vulkan or Metal performance, or who value the GT 645M's higher theoretical throughput and broader API support, the NVIDIA card has its place. The GT 645M's higher pixel and texture rates could also benefit traditional graphics workloads, though no direct gaming benchmarks are present in the data. Ultimately, the R5 M230's 70.8% OpenCL victory and higher average score make it the stronger overall choice, while the GT 645M's niche advantages in specific APIs and raw specs keep it relevant for targeted use cases.