GPU Comparison

The NVIDIA GeForce 825M and NVIDIA GeForce 920MX are both end-of-life mobile graphics solutions from NVIDIA, separated by two generations of architecture. The data presents a clear, if narrow, picture: the newer GeForce 920MX holds a definitive lead in the single available benchmark, yet both cards occupy a similar, low-performance tier. This analysis explores the implications of their specification and performance differences.

Head-to-Head Benchmarks

The only direct comparison available is the Geekbench OpenCL test, which measures general-purpose compute performance. In this test, the NVIDIA GeForce 920MX scores 4068, while the NVIDIA GeForce 825M scores 3694. This gives the 920MX a 9.2% advantage, a significant margin for two parts with such similar memory configurations.

This result is somewhat counterintuitive when looking at raw specifications. The 825M has a higher FP32 compute rating of 722.7 GFLOPS compared to the 920MX's 508.4 GFLOPS. It also has more shading units (384 vs 256) and more texture mapping units (32 vs 24). Despite this theoretical compute advantage, the 920MX wins decisively in the benchmark. This suggests the architectural efficiency of Maxwell is substantially superior to Kepler 2.0, allowing it to achieve better real-world performance with fewer resources.

The benchmark victory is not just a matter of a single score. The 920MX's nearest rivals in the database include the NVIDIA Quadro 2000M, which it beats by 2.7%. It also sits just behind the NVIDIA GeForce GT 735M, which is 2.4% faster. The 825M, by contrast, is essentially tied with the GeForce GT 740M, trailing by only 0.6%, and is 1.2% ahead of the AMD Radeon HD 6770. The 920MX's win is therefore not an outlier but a consistent performance step above its predecessor's closest competitors.

Interestingly, the percentile ranks tell a story of overall market positioning. The 825M sits at the 22nd percentile of all GPUs, while the 920MX is at the 21st percentile. This means that despite the 920MX being 9.2% faster in this test, both are in the same bottom quartile of overall performance. The marginal difference in percentile suggests that in a broad field of GPUs, this 9.2% delta is not enough to move the needle significantly; both are entry-level parts. The 920MX's average benchmark score of 3528 is actually lower than its OpenCL score because it also includes a Vulkan score of 2987, which drags its average down and places it in a similar performance class to the 825M.

FAQ

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

A: The NVIDIA GeForce 920MX is faster, scoring 4068 compared to the GeForce 825M's 3694, a 9.2% difference.

Q: How does the GeForce 825M compare to its direct rivals?

A: The data shows the 825M is nearly identical in performance to the GeForce GT 740M (0.6% slower) and the Quadro 3000M (0.6% slower), while being 1.2% faster than the AMD Radeon HD 6770.

Q: Does the GeForce 825M have a higher raw compute capability than the 920MX?

A: Yes, the FP32 performance of the 825M is 722.7 GFLOPS, which is higher than the 920MX's 508.4 GFLOPS, despite the 920MX winning the benchmark.

Q: What is the performance gap between the 920MX and its nearest rivals?

A: The 920MX is 2.7% faster than the Quadro 2000M but 1.8% slower than the GeForce GT 545 and 1.9% slower than the RTX 5000 Mobile Ada Generation.

Q: Are both GPUs considered equally powerful in the overall market?

A: No, the 825M is in the 22nd percentile of all GPUs, while the 920MX is in the 21st percentile, indicating they are both in the lowest quarter of overall performance.

Q: What are the memory specifications for each GPU?

A: Both use DDR3 memory with a 64-bit bus and 14.40 GB/s bandwidth. However, the 825M has 1024 MB of memory, while the 920MX has 2 GB.

Architecture Differences

The core difference lies in their architectures and manufacturing details. The GeForce 825M is built on the Kepler 2.0 architecture using the GK208 chip, while the GeForce 920MX utilizes the Maxwell architecture with the GM108S chip. Both are manufactured on a 28 nm process at TSMC, which explains their similar power and thermal profiles, but the designs diverge significantly.

The 825M's GK208 chip has a die size of 87 mm² and a transistor density of 11.7M / mm². The 920MX's GM108S chip is smaller at 77 mm² but packs the same 1,020 million transistors into that space, resulting in a higher density of 13.2M / mm². This denser design is a hallmark of architectural refinement, allowing Maxwell to deliver better performance per transistor.

The execution resources are starkly different. The 825M features 384 shading units, 32 TMUs, and 8 ROPs. The 920MX, despite having fewer resources (256 shading units and 24 TMUs), still manages to outperform it. This indicates that Maxwell's scheduling and instruction handling are more efficient than Kepler's. The 825M also has a higher texture rate of 30.11 GTexel/s compared to the 920MX's 23.83 GTexel/s, yet this does not translate into a benchmark win.

Clock speeds also favor the 920MX. It has a base clock of 965 MHz and a boost clock of 993 MHz, while the 825M runs at 850 MHz base and 941 MHz boost. The 920MX's higher clocks, combined with its architectural efficiency, are the primary drivers of its superior benchmark performance. Both GPUs support DirectX 12 (11_0), OpenGL 4.6, and have no dedicated RT or Tensor cores. The 920MX supports Vulkan 1.4, while the 825M is limited to Vulkan 1.2.175.

The Verdict

The benchmark data is unequivocal: the NVIDIA GeForce 920MX is the better performer. It wins the only head-to-head test by a solid 9.2% margin, achieving a score of 4068 against the 825M's 3694. For any user prioritizing compute performance in OpenCL workloads, the 920MX is the clear choice.

However, the broader data complicates the picture. The 920MX's average benchmark score is 3528, which is lower than its OpenCL score and places it closer to the 825M's performance. This is due to its weaker Vulkan score of 2987. This suggests that while the 920MX excels in OpenCL, its advantage may not be universal across all APIs. The 825M, with a single benchmark score, presents a more consistent, albeit lower, performance profile.

The 825M's theoretical advantages in raw compute (722.7 GFLOPS vs 508.4 GFLOPS), shading units, and texture rate are not reflected in the benchmark results. This indicates that the Kepler architecture is less efficient at translating raw specs into actual performance. The 920MX's Maxwell architecture, with its higher clock speeds and better efficiency, delivers a superior result despite having less hardware. The data suggests the 920MX is the superior product, and the 825M's higher compute rating is a meaningless figure in this comparison.

Specification Differences

The two GPUs differ in several key areas, with the most significant being architecture and memory capacity. The 825M uses the Kepler 2.0 architecture, while the 920MX uses Maxwell. This architectural change is the root of their performance differences.

• Chip: The 825M uses the GK208 chip, while the 920MX uses the GM108S chip.
• Die Size: The 825M has a larger die at 87 mm², while the 920MX is more compact at 77 mm².
• Transistor Density: The 920MX has a higher density of 13.2M / mm² compared to the 825M's 11.7M / mm².
• Base Clock: The 920MX runs at 965 MHz, which is higher than the 825M's 850 MHz.
• Boost Clock: The 920MX boosts to 993 MHz, while the 825M boosts to 941 MHz.
• Memory Size: The 825M has 1024 MB of memory, while the 920MX has double that at 2 GB.
• Shading Units: The 825M has 384 shading units, more than the 920MX's 256.
• TMUs: The 825M has 32 TMUs, compared to the 920MX's 24.
• Pixel Rate: The 920MX has a higher pixel rate of 7.944 GPixel/s versus the 825M's 7.528 GPixel/s.
• Texture Rate: The 825M has a higher texture rate of 30.11 GTexel/s, while the 920MX is limited to 23.83 GTexel/s.
• FP32 Performance: The 825M has a higher FP32 rating of 722.7 GFLOPS, while the 920MX is rated at 508.4 GFLOPS.
• TDP: The 825M has a TDP of 33 W, while the 920MX is more power-efficient at 16 W.
• Slot Width: The 825M is an IGP, while the 920MX is an MXM Module.
• Vulkan Support: The 920MX supports Vulkan 1.4, while the 825M supports only 1.2.175.

Where Each One Wins

For raw performance in the Geekbench OpenCL test, the NVIDIA GeForce 920MX is the definitive winner, with a 9.2% higher score. This makes it the preferable option for applications that rely on OpenCL compute acceleration. Its lower TDP of 16 W also makes it a more efficient choice for thin-and-light laptops where battery life and thermals are a concern.

The GeForce 825M, despite losing the benchmark, has theoretical advantages in raw compute power, with a higher FP32 rating and more shading units. It also offers a higher texture rate and a larger memory footprint in terms of its physical die size. However, these advantages do not materialize into better benchmark performance.

The 825M's higher TDP of 33 W indicates it is a more power-hungry part, which is a disadvantage in mobile devices. The 920MX's superior performance in the benchmark, combined with its lower power draw, makes it the more compelling choice for any new system. The data shows the 920MX wins the only measurable performance test, while the 825M's strengths remain purely theoretical and do not translate into a tangible victory.