AMD Radeon HD 8850M vs NVIDIA GeForce GTX 675MX Comparison

# Where Each One Wins

The benchmark data splits cleanly in favor of the NVIDIA GeForce GTX 675MX. Across the recorded Geekbench OpenCL test, the GTX 675MX posts a score of 10,723 against the AMD Radeon HD 8850M’s 7,447, a 44% advantage. That single head-to-head result is the only direct comparison available, and the NVIDIA part wins it outright.

The GTX 675MX also holds a broader performance profile in the database. Its average benchmark score across all recorded tests is 8,427, which places it in the 43rd percentile of all GPUs. The Radeon HD 8850M averages 7,447 and sits in the 40th percentile. So while both are mid-pack mobile parts, the NVIDIA chip sits one tier higher in aggregate performance.

The AMD side has no benchmark win in the recorded data. Its only listed score is the OpenCL result, and it loses that by a wide margin. However, the Radeon HD 8850M does have one structural advantage worth noting: it supports DirectX 12 at feature level 11_1, whereas the GTX 675MX supports DirectX 12 at feature level 11_0. For workloads that explicitly leverage the newer feature level, the AMD part is technically more current, though the recorded compute benchmarks do not reflect any such benefit.

For use-case splitting, the data suggests the GTX 675MX is the stronger compute performer, particularly for OpenCL-accelerated tasks. The Radeon HD 8850M, by contrast, offers a slightly newer DirectX feature set but trails in raw throughput. In gaming scenarios that rely on pixel and texture rates, the GTX 675MX also leads: it delivers 13.08 GPixel/s and 52.32 GTexel/s, versus the Radeon’s 10.00 GPixel/s and 25.00 GTexel/s.

# Architecture Differences

The two chips come from different design philosophies and different generations. The NVIDIA GeForce GTX 675MX uses the GK104 chip built on the Kepler architecture, fabricated by TSMC on a 28 nm process. It packs 3,540 million transistors into a 294 mm² die, yielding a transistor density of 12.0 million per square millimeter. The chip is part of the GeForce 600M generation, and the database lists it as end-of-life with a release date in 2012.

The AMD Radeon HD 8850M uses the Venus chip based on GCN 1.0 architecture, also fabricated by TSMC on 28 nm. It has 1,500 million transistors on a 123 mm² die, giving a transistor density of 12.2 million per square millimeter. This part belongs to the Solar System (HD 8800M) generation and was released in 2013. The die size difference is stark: the NVIDIA chip is more than twice the physical size of the AMD chip, and it carries more than double the transistor count.

Memory subsystems diverge as well. The GTX 675MX has 2 GB of GDDR5 on a 256-bit bus, producing 115.2 GB/s of bandwidth. The Radeon HD 8850M also has 2 GB of GDDR5 but on a 128-bit bus, yielding 64.00 GB/s. That is nearly half the bandwidth of the NVIDIA part, which helps explain the compute gap.

The compute resources also favor NVIDIA. The GTX 675MX has 960 shading units, 80 texture mapping units, and 32 ROPs. The Radeon HD 8850M has 640 shading units, 40 TMUs, and 16 ROPs. Clock speeds tell a mixed story: the AMD part runs at a 575 MHz base and 625 MHz boost, while the NVIDIA part lists only its memory clock of 900 MHz (3.6 Gbps effective). The AMD memory clock is 1000 MHz (4 Gbps effective), but the narrower bus negates that advantage.

Feature support differs in API versions: the GTX 675MX supports Vulkan 1.2.175 and OpenGL 4.6, while the Radeon HD 8850M supports Vulkan 1.2.170 and OpenGL 4.6. The bus interface also differs: NVIDIA uses an MXM-B (3.0) module, while AMD uses PCIe 3.0 x16. The NVIDIA part has a 100 W TDP and requires no power connectors; the AMD TDP is not recorded.

# Head-to-Head Benchmarks

The only direct benchmark comparison in the database is Geekbench OpenCL. The NVIDIA GeForce GTX 675MX scores 10,723, and the AMD Radeon HD 8850M scores 7,447. That is a 44% delta in favor of NVIDIA. This is a substantial lead, and it aligns with the underlying hardware differences: the GTX 675MX has 50% more shading units (960 vs. 640), double the TMUs (80 vs. 40), double the ROPs (32 vs. 16), and nearly double the memory bandwidth (115.2 GB/s vs. 64.00 GB/s).

The pixel and texture rates reinforce the same story. The GTX 675MX outputs 13.08 GPixel/s and 52.32 GTexel/s. The Radeon HD 8850M outputs 10.00 GPixel/s and 25.00 GTexel/s. The texture rate gap is particularly wide: NVIDIA is more than 100% ahead in texel throughput. The FP32 compute rating also favors NVIDIA at 1,255.7 GFLOPS versus 800.0 GFLOPS, a 57% lead.

Looking at the nearest rivals in the database, the GTX 675MX’s average score of 8,427 sits within a tight cluster. The AMD Radeon 880M is 0.1% ahead with 8,436, the NVIDIA GeForce MX330 is 0.4% ahead with 8,458, the AMD Radeon HD 8870M is 0.4% ahead with 8,462, and the AMD Radeon R9 M375X trails by 1.2% with 8,325. This indicates the GTX 675MX is positioned right at the boundary of a performance tier, neither clearly above nor below its immediate competition.

The Radeon HD 8850M’s average of 7,447 places it near the Intel UHD Graphics 750, which scores 7,441 (0.1% behind), and the AMD Radeon R7 350 at 7,425 (0.3% behind). The NVIDIA GeForce GTX 1650 is 0.3% ahead with 7,472, and the Intel Arc A310 leads this group by 1.4% with 7,550. This places the Radeon HD 8850M at the lower end of its immediate peer group.

# The Verdict

The data is unambiguous: the NVIDIA GeForce GTX 675MX is the faster GPU. It wins the only head-to-head benchmark by 44%, and it holds a higher average benchmark score (8,427 vs. 7,447) and a higher percentile ranking (43rd vs. 40th). Every measured throughput metric favors NVIDIA: pixel rate, texture rate, FP32 compute, and memory bandwidth.

The AMD Radeon HD 8850M is not without merit, but its advantages are narrow. It supports DirectX 12 at feature level 11_1, which is one step newer than the NVIDIA part’s 11_0. It also has a slightly higher transistor density (12.2M / mm² vs. 12.0M / mm²) and a faster effective memory clock (4 Gbps vs. 3.6 Gbps). But those specifications do not translate into benchmark wins.

For users choosing between these two in a mobile system, the GTX 675MX is the pick for compute-heavy workloads, OpenCL acceleration, and any task that benefits from higher texture and pixel throughput. The Radeon HD 8850M is the pick only if the DirectX 12 feature level 11_1 support is a hard requirement for a specific application, or if the smaller die and lower transistor count matter for thermal or power considerations, though the TDP for the AMD part is not recorded.

The database places the GTX 675MX in a competitive cluster with the AMD Radeon HD 8870M, NVIDIA GeForce MX330, and AMD Radeon 880M, all within 0.4% of each other. The Radeon HD 8850M sits in a lower cluster with integrated graphics and entry-level discrete parts. The performance gap between the two products is not marginal; it is a full tier of separation.

# FAQ

Q: Which GPU wins in raw compute performance?

A: The NVIDIA GeForce GTX 675MX wins the only head-to-head benchmark, Geekbench OpenCL, by 44% (10,723 vs. 7,447).

Q: How do their memory bandwidths compare?

A: The GTX 675MX has 115.2 GB/s of bandwidth on a 256-bit bus, while the Radeon HD 8850M has 64.00 GB/s on a 128-bit bus.

Q: What is the difference in shading units and texture units?

A: The GTX 675MX has 960 shading units and 80 TMUs; the Radeon HD 8850M has 640 shading units and 40 TMUs.

Q: Do both GPUs support the same DirectX version?

A: No. The GTX 675MX supports DirectX 12 at feature level 11_0, while the Radeon HD 8850M supports DirectX 12 at feature level 11_1.

Q: How do their average benchmark scores compare to nearby rivals?

A: The GTX 675MX averages 8,427, within 0.4% of the AMD Radeon 880M, NVIDIA GeForce MX330, and AMD Radeon HD 8870M. The Radeon HD 8850M averages 7,447, within 0.3% of the Intel UHD Graphics 750 and AMD Radeon R7 350.

Q: Which GPU has a larger die and more transistors?

A: The GTX 675MX has a 294 mm² die with 3,540 million transistors; the Radeon HD 8850M has a 123 mm² die with 1,500 million transistors.