AMD Radeon R7 M340 vs AMD Radeon R7 M365X Comparison

The AMD Radeon R7 M365X and AMD Radeon R7 M340 are both end-of-life mobile GPUs from the same Gem System (R7 M300) generation, released on the same date, but they are built on different architectures and target different performance profiles. The M365X uses the Litho chip based on GCN 1.0, while the M340 uses the Meso chip based on GCN 3.0. Benchmark results show a split decision: the M365X wins Geekbench OpenCL by a substantial 20.4% margin, while the M340 counters with a 5.8% win in Geekbench Vulkan. Average scores place the M365X at 5416 versus 5063 for the M340, yet the M340's average exactly matches its closest rival, suggesting a tighter field around its performance level.

FAQ

Q: Which GPU has the higher average benchmark score?

A: The AMD Radeon R7 M365X leads with an average benchmark score of 5416, compared to the AMD Radeon R7 M340's 5063. This places the M365X at the 32nd percentile of all GPUs, while the M340 sits at the 30th percentile.

Q: How do the two GPUs compare in OpenCL performance?

A: The M365X is significantly faster in Geekbench OpenCL, scoring 5939 against the M340's 4932. That is a 20.4% advantage for the M365X, making it the clear winner for compute workloads that rely on OpenCL.

Q: Does the M340 win any benchmark?

A: Yes, the M340 takes the Geekbench Vulkan test with a score of 5193 versus the M365X's 4893. The delta is 5.8% in favor of the M340, showing it has an edge in Vulkan-based applications.

Q: What are the memory specifications for each GPU?

A: The M365X has 1024 MB of GDDR5 memory on a 128-bit bus, delivering 64.00 GB/s bandwidth. The M340 has 2 GB of DDR3 memory on a 64-bit bus, providing only 16.00 GB/s bandwidth. The M365X has four times the memory bandwidth.

Q: Which GPU has higher FP32 performance?

A: The M340 is marginally ahead in raw FP32 throughput, delivering 653.4 GFLOPS compared to the M365X's 633.6 GFLOPS. The difference is about 3.1%, favoring the M340 despite its lower shading unit count.

Q: Are both GPUs from the same generation?

A: Yes, both are part of the Gem System (R7 M300) generation and were released on 2015-05-04. Both use a 28 nm process node from TSMC, but they use different chips: Litho for the M365X and Meso for the M340.

Architecture Differences

The M365X is built on the GCN 1.0 architecture using the Litho chip, while the M340 uses the GCN 3.0 architecture with the Meso chip. This generational gap in architecture explains several divergences in feature support and compute capabilities. The M365X's GCN 1.0 supports DirectX 12 (11_1), whereas the M340's GCN 3.0 supports DirectX 12 (12_0), giving the M340 a more complete feature set for modern DirectX 12 titles. Both support OpenGL 4.6 and Vulkan 1.2.170, so API coverage is otherwise identical.

The physical silicon differs significantly. The M365X's Litho chip is smaller at 77 mm² with 950 million transistors, while the M340's Meso chip is 125 mm² with 1,550 million transistors. Transistor density is nearly identical (12.3M per mm² for the M365X, 12.4M per mm² for the M340), but the M340 packs more transistors into a larger die. This allows the M340 to have a higher base clock of 943 MHz and boost clock of 1021 MHz, whereas the M365X has no listed base or boost clocks. The M340 also supports FP16 at 1:1 ratio (653.4 GFLOPS), a feature absent from the M365X's spec sheet.

Memory architecture is a major differentiator. The M365X uses 1 GB of GDDR5 on a 128-bit bus, achieving 64.00 GB/s of bandwidth. The M340 uses 2 GB of DDR3 on a 64-bit bus, achieving only 16.00 GB/s. This is a fourfold bandwidth advantage for the M365X, which can be critical for texture-heavy workloads. However, the M340's 2 GB capacity is double that of the M365X, which helps with larger datasets and higher-resolution textures, albeit at much lower speed.

The shading and texture configurations also differ. The M365X has 384 shading units, 24 TMUs, and 8 ROPs. The M340 has 320 shading units, 20 TMUs, and 8 ROPs. Despite fewer units, the M340 achieves a higher pixel rate of 8.168 GPixel/s versus 6.600 GPixel/s for the M365X, and a slightly higher texture rate of 20.42 GTexel/s versus 19.80 GTexel/s. This is attributable to the M340's higher clock speeds.

The Verdict

The data presents a clear split based on workload. For OpenCL compute tasks, the AMD Radeon R7 M365X is the definitive choice, delivering a 20.4% higher score than the M340. Its GDDR5 memory and 128-bit bus provide 64.00 GB/s bandwidth, which is four times the M340's 16.00 GB/s, making it far more suitable for bandwidth-sensitive operations. The M365X also has more shading units (384 vs 320), which helps in parallel compute loads.

For Vulkan-based gaming or applications, the AMD Radeon R7 M340 is the better pick. It wins the Geekbench Vulkan test by 5.8%, and its GCN 3.0 architecture supports DirectX 12 (12_0), which is more modern than the M365X's DirectX 12 (11_1). The M340 also offers double the memory capacity (2 GB vs 1 GB), which can prevent stuttering in modern titles that exceed 1 GB of VRAM usage.

The average scores favor the M365X (5416 vs 5063), but the M340's average exactly matches its nearest rival, the AMD Radeon R7 240, indicating it is a more typical performer in its class. The M365X's nearest rival is the AMD Radeon 610M, which it trails by only 0.5%. Neither GPU is a performance king in absolute terms, but they serve different niches: the M365X for compute and bandwidth, the M340 for modern API support and memory capacity.

Specification Differences

The two GPUs differ across several key specification fields. The M365X uses the Litho chip with GCN 1.0 architecture, while the M340 uses the Meso chip with GCN 3.0. The M365X has 950 million transistors on a 77 mm² die, whereas the M340 has 1,550 million transistors on a 125 mm² die. Both are fabricated on a 28 nm process by TSMC.

Clock speeds are only listed for the M340, which has a 943 MHz base and 1021 MHz boost. The M365X has no listed base or boost clocks. Memory clocks are the same at 1000 MHz, but effective speeds differ: the M365X runs at 4 Gbps effective due to GDDR5, while the M340 runs at 2 Gbps effective due to DDR3.

Memory configuration is starkly different. The M365X has 1024 MB of GDDR5 on a 128-bit bus with 64.00 GB/s bandwidth. The M340 has 2 GB of DDR3 on a 64-bit bus with 16.00 GB/s bandwidth. The M365X has 384 shading units, 24 TMUs, and 8 ROPs. The M340 has 320 shading units, 20 TMUs, and 8 ROPs.

Pixel and texture rates favor the M340: 8.168 GPixel/s and 20.42 GTexel/s versus 6.600 GPixel/s and 19.80 GTexel/s for the M365X. FP32 performance is close, with the M340 at 653.4 GFLOPS and the M365X at 633.6 GFLOPS. The M340 also lists FP16 at 653.4 GFLOPS (1:1), a capability not specified for the M365X. DirectX support differs: the M365X supports 12 (11_1), while the M340 supports 12 (12_0). Both share OpenGL 4.6, Vulkan 1.2.170, and PCIe 3.0 x8 interfaces.

Head-to-Head Benchmarks

The Geekbench OpenCL test shows the M365X dominating with a score of 5939 against the M340's 4932. This is a 20.4% advantage for the M365X, which is a substantial margin in GPU terms. The M365X's GDDR5 memory and 128-bit bus are the likely reasons, as OpenCL workloads often stress memory bandwidth heavily. The M340's DDR3 memory at 16.00 GB/s is a severe bottleneck in this scenario.

The Geekbench Vulkan test flips the result. The M340 scores 5193, beating the M365X's 4893 by 5.8%. This is a more modest margin, but it is still a clear win. The M340's GCN 3.0 architecture likely has better Vulkan driver optimization and scheduling, which compensates for its lower memory bandwidth. The M340's higher clock speeds (943 MHz base, 1021 MHz boost) also contribute to its Vulkan performance.

Looking at the nearest rivals for context, the M365X's average score of 5416 is just 0.5% below the AMD Radeon 610M's 5444 and 0.9% above the Intel UHD Graphics P630's 5370. The M340's average of 5063 exactly matches the AMD Radeon R7 240, and it is 0.6% ahead of the AMD FirePro W4170M. These deltas show that the M365X competes in a slightly higher performance tier than the M340.

The win count is even at one each, but the magnitude of the wins differs. The M365X's OpenCL victory is 20.4%, which is over three times larger than the M340's 5.8% Vulkan win. This suggests that the M365X's advantages are more pronounced in its winning workload, while the M340's edge is narrower.

Where Each One Wins

The AMD Radeon R7 M365X wins in compute-heavy scenarios that leverage OpenCL. Its 64.00 GB/s of memory bandwidth is four times that of the M340, making it far superior for tasks like video encoding, scientific simulations, or any workload that moves large amounts of data. The M365X also has more shading units (384 vs 320), which helps with parallel processing. Its average score is 5416, placing it at the 32nd percentile, and it beats the M340 by 20.4% in OpenCL. If you are running applications that are bandwidth-bound, the M365X is the clear pick.

The AMD Radeon R7 M340 wins in Vulkan-based scenarios and modern API gaming. Its 5.8% lead in Geekbench Vulkan (5193 vs 4893) indicates better driver efficiency with Vulkan. The M340 also supports DirectX 12 (12_0), which is a more complete implementation than the M365X's DirectX 12 (11_1). This means newer games that require DirectX 12 features may run better on the M340. Additionally, the M340 has 2 GB of VRAM versus 1 GB on the M365X, which is a practical advantage for games with larger texture sets. The M340's higher pixel rate (8.168 GPixel/s vs 6.600 GPixel/s) also helps with fill-rate-bound scenes.

For raw compute throughput, the M340 is marginally ahead in FP32 (653.4 GFLOPS vs 633.6 GFLOPS) and offers FP16 support at 1:1, which the M365X lacks. This makes the M340 slightly better for mixed-precision workloads. However, the M365X's memory bandwidth advantage is so large that it likely outweighs the M340's compute advantages in most real-world tasks. The M340's average score is 5063, which is at the 30th percentile, and it is evenly matched with its nearest rival, the AMD Radeon R7 240.

In summary, the M365X is the winner for OpenCL compute and bandwidth-intensive tasks, while the M340 is the winner for Vulkan gaming and modern API support. The M365X's overall average score is higher (5416 vs 5063), but the M340's 2 GB VRAM and GCN 3.0 architecture make it more future-proof for modern software. Choose based on your primary workload: OpenCL performance favors the M365X, while Vulkan and DirectX 12 (12_0) favor the M340.