AMD Radeon RX 6400 vs NVIDIA GeForce GTX 670MX Comparison

# AMD Radeon RX 6400 vs NVIDIA GeForce GTX 670MX

The AMD Radeon RX 6400 and NVIDIA GeForce GTX 670MX occupy different eras of graphics technology, and the benchmark data reflects that chasm clearly. Across the two shared tests, the RX 6400 wins both, with margins of 422.6% in Geekbench OpenCL and 208% in Geekbench Vulkan. The RX 6400 sits at the 35th percentile of all GPUs with an average benchmark score of 6001, while the GTX 670MX lands at the 33rd percentile with an average of 5721. The RX 6400’s nearest rivals are the NVIDIA GeForce GTX 770M (delta 0%), RTX PRO 6000 Blackwell Server (delta 0.1%), and AMD FirePro W4100 (delta 0.2%). The GTX 670MX’s closest competitors include the Intel Iris Pro Graphics P6300 (delta 0.2%), NVIDIA GeForce GTX 550 Ti (delta -0.2%), and AMD Radeon HD 8790M (delta 0.5%). These percentile positions are close, but the raw performance gap in compute workloads is anything but.

The Verdict

The data points to a decisive recommendation: the AMD Radeon RX 6400 is the superior choice for anyone prioritizing raw compute performance and modern API support. Its Geekbench OpenCL score of 32011 dwarfs the GTX 670MX’s 6125, a 422.6% advantage that suggests the RX 6400 handles general-purpose GPU workloads at a fundamentally different level. The Vulkan gap is similarly stark—16372 versus 5316, a 208% lead—indicating that the RX 6400 is far better equipped for modern graphics APIs. The GTX 670MX, with only Geekbench OpenCL and Vulkan results in its benchmark suite, offers no counterpoint; it wins zero head-to-head tests. For users with legacy software that relies on older DirectX versions, however, the GTX 670MX’s DirectX 12 (11_0) support might still function, but the RX 6400’s DirectX 12 Ultimate (12_2) is a forward-looking feature set that the older card cannot match. The RX 6400’s average benchmark score of 6001 versus 5721 for the GTX 670MX is a modest overall margin, but the compute-specific deltas reveal the true story: this is not a close contest in modern workloads. The GTX 670MX could be considered only in the narrow case of a system with strict power or interface constraints where the RX 6400’s PCIe 4.0 x4 bus might be a limitation—but even then, the data shows the RX 6400’s performance ceiling is far higher.

Architecture Differences

The architectural gulf between these two GPUs is vast, rooted in a decade of evolution. The RX 6400 uses the Navi 24 chip built on RDNA 2.0 architecture, fabricated on a 6 nm process at TSMC with 5,400 million transistors packed into a 107 mm² die—a transistor density of 50.5M per mm². The GTX 670MX uses the GK104 chip with Kepler architecture, made on a 28 nm process also at TSMC, but with fewer transistors (3,540 million) spread across a much larger 294 mm² die, yielding a density of just 12.0M per mm². That density difference—over 4x—explains why the RX 6400 can deliver dramatically higher clock speeds: base 1923 MHz and boost 2321 MHz versus the GTX 670MX’s fixed 601 MHz. The RX 6400 features 768 shading units, 48 texture mapping units, 32 ROPs, and 12 ray tracing cores; the GTX 670MX has 960 shading units, 80 TMUs, and 24 ROPs, but no ray tracing hardware. The RX 6400 supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4, while the GTX 670MX is limited to DirectX 12 (11_0), OpenGL 4.6, and Vulkan 1.2.175. The RX 6400’s memory subsystem uses 4 GB of GDDR6 on a 64-bit bus with 128.0 GB/s bandwidth, while the GTX 670MX has 3 GB of GDDR5 on a 192-bit bus with only 67.20 GB/s. The RX 6400 also supports PCIe 4.0 x4, whereas the GTX 670MX uses PCIe 3.0 x16—a bus that is wider but older and slower per lane. The RX 6400’s pixel rate of 74.27 GPixel/s and texture rate of 111.4 GTexel/s crush the GTX 670MX’s 12.02 GPixel/s and 48.08 GTexel/s, respectively.

FAQ

Q: Which GPU has higher raw compute performance?

A: The RX 6400, with an FP32 throughput of 3.565 TFLOPS versus the GTX 670MX’s 1,153.9 GFLOPS (approximately 1.15 TFLOPS). The RX 6400 also supports FP16 at 7.130 TFLOPS (2:1), which the GTX 670MX does not list.

Q: How do the memory bandwidths compare?

A: The RX 6400 delivers 128.0 GB/s from 4 GB of GDDR6 on a 64-bit bus, while the GTX 670MX manages 67.20 GB/s from 3 GB of GDDR5 on a 192-bit bus. Despite the narrower bus, the RX 6400’s faster memory type and higher effective speed (16 Gbps vs 2.8 Gbps) give it nearly double the bandwidth.

Q: Does the GTX 670MX support ray tracing?

A: No. The GTX 670MX has no ray tracing cores (rtCores: null), while the RX 6400 includes 12 dedicated RT cores, a key feature for modern games and applications.

Q: Which card is more power-efficient?

A: The RX 6400 has a TDP of 53 W and requires no power connectors, with a suggested PSU of 250 W. The GTX 670MX has a higher TDP of 75 W, also with no power connectors, but no suggested PSU is listed. The RX 6400’s lower power draw combined with far higher performance indicates superior efficiency.

Q: What is the launch MSRP of the RX 6400?

A: The RX 6400 has a launch MSRP of 159 USD. The GTX 670MX has no listed launch MSRP in the data.

Q: How do their benchmark percentiles compare?

A: The RX 6400 is at the 35th percentile of all GPUs, while the GTX 670MX is at the 33rd percentile. Their average benchmark scores are 6001 and 5721, respectively, a difference of about 4.9%.

Specification Differences

The two GPUs differ across nearly every specification field. The RX 6400 is built on a 6 nm process versus the GTX 670MX’s 28 nm, with the RX 6400 using 5,400 million transistors on a 107 mm² die compared to 3,540 million on 294 mm². Clock speeds: the RX 6400 has base 1923 MHz, boost 2321 MHz, and game 2039 MHz, while the GTX 670MX is locked at 601 MHz base and boost with no game clock listed. Memory: the RX 6400 has 4 GB GDDR6 at 2000 MHz (16 Gbps effective) on a 64-bit bus; the GTX 670MX has 3 GB GDDR5 at 700 MHz (2.8 Gbps effective) on a 192-bit bus. Bandwidth: 128.0 GB/s versus 67.20 GB/s. The RX 6400 has 768 shading units, 48 TMUs, 32 ROPs, and 12 RT cores; the GTX 670MX has 960 shading units, 80 TMUs, 24 ROPs, and no RT cores. Pixel and texture rates: 74.27 GPixel/s and 111.4 GTexel/s for the RX 6400, versus 12.02 GPixel/s and 48.08 GTexel/s for the GTX 670MX. FP32: 3.565 TFLOPS versus 1,153.9 GFLOPS. TDP: 53 W versus 75 W. Bus interface: PCIe 4.0 x4 versus PCIe 3.0 x16. Display outputs: the RX 6400 has 1x HDMI 2.1 and 1x DisplayPort 1.4a, while the GTX 670MX is "Portable Device Dependent." API support: DirectX 12 Ultimate (12_2) versus DirectX 12 (11_0), Vulkan 1.4 versus 1.2.175. The RX 6400’s release date is 2022-01-18, while the GTX 670MX launched on 2012-09-30. The RX 6400 has a launch MSRP of 159 USD; the GTX 670MX has none.

Head-to-Head Benchmarks

The head-to-head data is lopsided, with the RX 6400 winning both available tests. In Geekbench OpenCL, the RX 6400 scores 32011 against the GTX 670MX’s 6125, a delta of 422.6%. This is the single largest margin in the comparison and suggests that the RX 6400’s modern architecture and higher clock speeds translate into massive gains in compute-heavy applications like rendering, physics simulation, or machine learning inference. The Geekbench Vulkan test shows a similar story: the RX 6400’s 16372 versus 5316, a 208% advantage. Vulkan is a low-overhead API that scales well with raw hardware capabilities, and the RX 6400’s RDNA 2.0 design with explicit support for Vulkan 1.4 clearly outperforms the Kepler-based GTX 670MX, which is limited to Vulkan 1.2.175. The RX 6400’s win count is 2, while the GTX 670MX has 0 wins. The overall average benchmark scores—6001 for the RX 6400 and 5721 for the GTX 670MX—are closer than the head-to-head deltas, but this is because the RX 6400’s benchmark suite includes additional tests (like Passmark variants) that dilute its compute dominance. The GTX 670MX’s sparse benchmark record (only two tests) means its average is based on fewer data points, potentially masking even wider gaps in other workloads.

Where Each One Wins

Based strictly on the data, the RX 6400 wins in every measurable category. In compute-heavy workloads like OpenCL and Vulkan, it is vastly superior—422.6% and 208% ahead, respectively. The RX 6400’s higher pixel rate (74.27 GPixel/s vs 12.02 GPixel/s) and texture rate (111.4 GTexel/s vs 48.08 GTexel/s) indicate it will excel in games that push fill-rate limits, while its 12 RT cores provide hardware-accelerated ray tracing that the GTX 670MX cannot perform at all. The RX 6400’s lower TDP (53 W vs 75 W) and superior transistor density (50.5M / mm² vs 12.0M / mm²) suggest it is also the better choice for thermally constrained systems or battery-powered devices, though the GTX 670MX’s "Portable Device Dependent" display outputs imply it was designed for laptops. The GTX 670MX’s only conceivable advantage lies in its wider 192-bit memory bus and higher shading unit count (960 vs 768), but the RX 6400’s faster GDDR6 memory and higher clocks render those raw counts moot in practice. The GTX 670MX’s PCIe 3.0 x16 interface is wider than the RX 6400’s PCIe 4.0 x4, but the newer standard’s higher per-lane bandwidth means the RX 6400’s effective throughput is likely comparable. For anyone choosing between these two today, the RX 6400 is the only rational pick based on performance data, with the GTX 670MX relegated to legacy systems that cannot accommodate newer cards or drivers.