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

The AMD Radeon HD 8850M and the NVIDIA GeForce GTX 675M are two end-of-life mobile graphics processors from different architectural generations, and the single benchmark available shows a clear, albeit modest, lead for the AMD part. In the Geekbench OpenCL test, the HD 8850M scores 7447, which is 7.2% higher than the GTX 675M’s 6946. This head-to-head result places the two GPUs in adjacent performance tiers, yet the underlying design philosophies that produced this outcome could not be more different.

Head-to-Head Benchmarks

The only direct comparison available is the Geekbench OpenCL compute test, and it decisively favors the AMD Radeon HD 8850M. The AMD part scores 7447, while the NVIDIA GeForce GTX 675M manages 6946, producing a delta of 7.2% in favor of the newer chip. This is not a landslide victory, but it is a consistent one — the HD 8850M wins the sole benchmark in the dataset, giving it a 1-0 record in head-to-head wins.

Contextualizing these scores against their nearest rivals shows how close these two GPUs are in the broader market. The HD 8850M’s 7447 score puts it 0.1% ahead of the Intel UHD Graphics 750 (7441) and 0.3% ahead of the AMD Radeon R7 350 (7425), yet it trails the NVIDIA GeForce GTX 1650 by 0.3% (7472) and the Intel Arc A310 by 1.4% (7550). This places the AMD chip in a tightly packed cluster where a single percentage point separates it from several modern competitors.

The GTX 675M, meanwhile, sits in a slightly lower performance band with its 6946 score. It is 0.4% behind the AMD Radeon R5 M240 (6975) and 1.1% behind the NVIDIA GeForce GTX 680M (7023), but it leads the AMD FirePro M5100 by 1.7% (6830). Interestingly, the GTX 675M’s closest rival in the data is the Radeon R5 M240, which is itself an AMD part — suggesting that the NVIDIA chip’s performance profile is well understood in comparison to the competition.

In terms of overall percentile ranking, the HD 8850M places in the 40th percentile of all GPUs, while the GTX 675M sits just one percentile lower at 39. This difference is marginal in real-world terms, but it reinforces the notion that the AMD part holds a slight edge in raw compute performance. The 7.2% delta between the two is meaningful enough to shift a user from one performance tier to the next, but it is hardly the kind of gap that would define a generational leap.

The Verdict

Based strictly on the benchmark data, the AMD Radeon HD 8850M is the faster GPU. It wins the only head-to-head test available, posts a higher average benchmark score, and achieves a higher percentile ranking than the NVIDIA GeForce GTX 675M. For anyone choosing between these two for compute-oriented tasks — such as OpenCL-accelerated applications — the HD 8850M is the safer pick.

However, the GTX 675M is not without its own merits. The data shows that it delivers a respectable 6946 Geekbench OpenCL score, which places it within striking distance of the HD 8850M despite being an older design. The NVIDIA part’s nearest rival, the AMD Radeon R5 M240, trails it by 0.4%, and it outperforms the AMD FirePro M5100 by 1.7%. This suggests that while it loses the head-to-head, it remains competitive in its own performance tier.

The choice ultimately depends on what the user prioritizes. If raw compute performance is the sole criterion, the HD 8850M wins outright. But if the user is constrained by system compatibility — specifically a need for an MXM-B module form factor — the GTX 675M becomes the only viable option, as the HD 8850M’s bus interface is listed as PCIe 3.0 x16 without a corresponding slot width. In laptop environments where the GPU is not user-swappable, the decision may be moot. Given the data, the HD 8850M is the recommended part for performance, while the GTX 675M remains a competent fallback.

Architecture Differences

The two GPUs represent fundamentally different architectural approaches. The AMD Radeon HD 8850M is built on GCN 1.0, AMD’s Graphics Core Next architecture, fabricated on a 28 nm process at TSMC. The NVIDIA GeForce GTX 675M uses the Fermi 2.0 architecture, also produced by TSMC, but on a larger 40 nm process node. This process difference is significant: the AMD chip packs 1,500 million transistors into a 123 mm² die, yielding a transistor density of 12.2 million transistors per square millimeter. The NVIDIA chip, by contrast, contains 1,950 million transistors spread across a much larger 332 mm² die, resulting in a density of just 5.9 million transistors per square millimeter — roughly half that of the AMD part.

The compute resources reflect these architectural choices. The HD 8850M features 640 shading units, 40 texture mapping units (TMUs), and 16 raster output units (ROPs). The GTX 675M has fewer shading units at 384, but compensates with 64 TMUs and 32 ROPs — double the texture and pixel processing capacity of the AMD chip. This explains why the GTX 675M achieves a texture rate of 39.68 GTexel/s versus the HD 8850M’s 25.00 GTexel/s, and a pixel rate of 9.920 GPixel/s versus 10.00 GPixel/s — nearly identical pixel throughput despite the architectural differences.

Clock speeds also diverge sharply. The HD 8850M runs at a base clock of 575 MHz with a boost up to 625 MHz, while the GTX 675M has no listed base or boost clocks in the data. The AMD chip’s memory operates at 1000 MHz (4 Gbps effective), whereas the NVIDIA part’s memory runs at 750 MHz (3 Gbps effective). Despite the lower memory clock, the GTX 675M achieves higher bandwidth — 96.00 GB/s versus 64.00 GB/s — because it uses a 256-bit memory bus compared to the HD 8850M’s 128-bit bus.

Both GPUs support DirectX 12, but at different feature levels: the HD 8850M supports DirectX 12 (11_1), while the GTX 675M supports DirectX 12 (11_0). Both offer OpenGL 4.6, but only the AMD part lists Vulkan support (version 1.2.170); the NVIDIA chip has no Vulkan support listed. The GTX 675M also carries a 100 W TDP, while the HD 8850M has no TDP listed in the data.

Specification Differences

The most obvious specification difference is the process node: the HD 8850M uses 28 nm while the GTX 675M uses 40 nm. This leads to the substantial die size discrepancy — 123 mm² for the AMD chip versus 332 mm² for the NVIDIA chip — and the corresponding transistor density gap of 12.2M / mm² versus 5.9M / mm². The transistor counts also differ, with the GTX 675M holding 1,950 million transistors versus 1,500 million for the HD 8850M.

Memory configuration presents another clear distinction. Both GPUs feature 2 GB of GDDR5, but the HD 8850M uses a 128-bit bus with 64.00 GB/s bandwidth, while the GTX 675M employs a 256-bit bus with 96.00 GB/s bandwidth. Memory clocks differ as well: 1000 MHz (4 Gbps effective) for the AMD part versus 750 MHz (3 Gbps effective) for the NVIDIA part.

Compute unit counts are markedly different. The HD 8850M has 640 shading units, 40 TMUs, and 16 ROPs. The GTX 675M has 384 shading units, 64 TMUs, and 32 ROPs. These translate to different fill rates: the HD 8850M posts a pixel rate of 10.00 GPixel/s and a texture rate of 25.00 GTexel/s, while the GTX 675M achieves 9.920 GPixel/s and 39.68 GTexel/s respectively. Floating-point performance (FP32) is 800.0 GFLOPS for the AMD chip and 952.3 GFLOPS for the NVIDIA chip.

The bus interface is another differentiator: the HD 8850M uses PCIe 3.0 x16, while the GTX 675M uses MXM-B (3.0) with an MXM Module slot width. The GTX 675M lists a 100 W TDP and no power connectors, while the HD 8850M has no TDP or power connector data. Display outputs are listed as "Portable Device Dependent" for the NVIDIA part, with no display output information for the AMD part. Finally, the release dates differ — the HD 8850M launched on 2013-03-31, while the GTX 675M launched on 2012-03-21 — making the AMD part roughly a year newer.

FAQ

Q: Which GPU is faster in the Geekbench OpenCL benchmark?

A: The AMD Radeon HD 8850M is faster, scoring 7447 compared to the NVIDIA GeForce GTX 675M’s 6946, a delta of 7.2% in favor of the AMD part.

Q: How does the AMD Radeon HD 8850M compare to its nearest rivals?

A: The HD 8850M is 0.1% ahead of the Intel UHD Graphics 750 (7441), 0.3% ahead of the AMD Radeon R7 350 (7425), 0.3% behind the NVIDIA GeForce GTX 1650 (7472), and 1.4% behind the Intel Arc A310 (7550).

Q: What is the performance percentile of the NVIDIA GeForce GTX 675M?

A: The GTX 675M ranks in the 39th percentile of all GPUs, one percentile lower than the HD 8850M’s 40th percentile.

Q: Does the NVIDIA GeForce GTX 675M support Vulkan?

A: No, the GTX 675M does not list Vulkan support, while the AMD Radeon HD 8850M supports Vulkan version 1.2.170.

Q: Which GPU has higher memory bandwidth?

A: The NVIDIA GeForce GTX 675M has higher memory bandwidth at 96.00 GB/s, compared to the AMD Radeon HD 8850M’s 64.00 GB/s, due to its 256-bit memory bus versus the AMD part’s 128-bit bus.

Q: What is the transistor density of each GPU?

A: The AMD Radeon HD 8850M has a transistor density of 12.2 million transistors per square millimeter, while the NVIDIA GeForce GTX 675M has a density of 5.9 million transistors per square millimeter.