AMD Radeon HD 8750M vs NVIDIA Quadro K620M Comparison

The AMD Radeon HD 8750M and NVIDIA Quadro K620M are two end-of-life mobile graphics processors that land in the same performance tier, separated by a razor-thin margin in the benchmark data. The Radeon HD 8750M edges out the Quadro K620M in the sole OpenCL benchmark, scoring 5970 against 5957, a delta of just 0.2%. Both GPUs sit at the 34th percentile among all GPUs, indicating they are entry-level parts by modern standards. The data shows these two parts are effectively interchangeable in raw compute performance, but their architectural approaches and memory configurations reveal distinct design philosophies.

Where Each One Wins

The AMD Radeon HD 8750M claims the only head-to-head benchmark victory, winning the Geekbench OpenCL test with a score of 5970 over the Quadro K620M's 5957. This 0.2% advantage is marginal, but it does represent a measurable win for AMD in raw compute throughput. The Radeon's higher memory bandwidth of 28.80 GB/s, achieved through a 128-bit bus, gives it an edge in memory-bound workloads that the Quadro's narrower 64-bit bus cannot match. The Radeon also offers more texture mapping units (24 vs 16), which contributes to a higher texture fill rate of 19.80 GTexel/s compared to the Quadro's 17.98 GTexel/s.

The NVIDIA Quadro K620M counters with advantages in clock speed and pixel throughput. Its base clock of 1029 MHz and boost clock of 1124 MHz are substantially higher than the Radeon's 775 MHz base and 825 MHz boost. This clock advantage translates to a superior pixel rate of 8.992 GPixel/s versus the Radeon's 6.600 GPixel/s. The Quadro also delivers higher FP32 compute performance at 863.2 GFLOPS, compared to the Radeon's 633.6 GFLOPS, a 36% advantage in raw floating-point capability. The Quadro's higher transistor density of 13.2M per mm², versus the Radeon's 12.3M per mm², reflects a more efficient use of the same 77 mm² die size.

Architecture Differences

The two GPUs come from fundamentally different architectural lineages. The AMD Radeon HD 8750M is built on GCN 1.0 architecture, utilizing the Mars chip, and belongs to the Solar System generation (HD 8700M series). The NVIDIA Quadro K620M employs the Maxwell architecture with the GM108S chip, and is part of the Quadro Kepler-M generation (Kx200M series). Both are fabricated by TSMC on a 28 nm process, which is where their manufacturing similarities end.

The transistor counts differ notably: the Radeon packs 950 million transistors, while the Quadro contains 1,020 million. Despite the Quadro having more transistors, both dies are exactly 77 mm² in size, meaning the NVIDIA part achieves a higher transistor density of 13.2M per mm² versus AMD's 12.3M per mm². The memory subsystems represent the most striking architectural divergence. The Radeon uses 1024 MB of DDR3 on a 128-bit bus, delivering 28.80 GB/s of bandwidth. The Quadro uses 2 GB of DDR3 on a 64-bit bus, delivering only 16.02 GB/s. The Radeon's bus width advantage is decisive for bandwidth, while the Quadro's double memory capacity benefits applications needing larger working sets.

Clock behavior also differs dramatically. The Quadro runs at 1029 MHz base and 1124 MHz boost, while the Radeon runs at 775 MHz base and 825 MHz boost. This 28% to 36% clock advantage partially compensates for the Quadro's narrower memory bus. The Radeon's memory operates at 900 MHz with 1800 Mbps effective, while the Quadro's memory runs at 1001 MHz with 2 Gbps effective. The Radeon features 384 shading units and 24 TMUs, while the Quadro also has 384 shading units but only 16 TMUs. Both share 8 ROPs.

FAQ

Q: Which GPU is faster in OpenCL compute performance?

A: The AMD Radeon HD 8750M scores 5970 in Geekbench OpenCL, which is 0.2% higher than the NVIDIA Quadro K620M's 5957. This makes the Radeon the winner of the head-to-head benchmark, though the margin is negligible.

Q: How do their memory bandwidth figures compare?

A: The Radeon HD 8750M has a significant bandwidth advantage, delivering 28.80 GB/s over a 128-bit bus. The Quadro K620M provides only 16.02 GB/s over a 64-bit bus, which is roughly 44% lower bandwidth.

Q: Which GPU offers more memory capacity?

A: The NVIDIA Quadro K620M offers 2 GB of DDR3 memory, which is double the 1024 MB available on the AMD Radeon HD 8750M. This could be beneficial for workloads with larger data footprints.

Q: What is the FP32 compute performance difference?

A: The Quadro K620M achieves 863.2 GFLOPS of FP32 throughput, which is 36% higher than the Radeon HD 8750M's 633.6 GFLOPS. The Quadro's higher clock speeds drive this advantage.

Q: Do both GPUs support modern API features?

A: The Radeon HD 8750M supports DirectX 12 (11_1), OpenGL 4.6, and Vulkan 1.2.170. The Quadro K620M supports DirectX 12 (11_0), OpenGL 4.6, and Vulkan 1.4. The Quadro has a newer Vulkan version, while the Radeon has a marginally higher DirectX feature level.

Q: Which GPU has a higher pixel fill rate?

A: The NVIDIA Quadro K620M has a pixel rate of 8.992 GPixel/s, which is 36% higher than the Radeon HD 8750M's 6.600 GPixel/s. This is a direct consequence of the Quadro's higher clock speeds.

Specification Differences

The two GPUs differ across several key specification categories. The most significant differences are in memory bandwidth, clock speeds, and compute throughput. The Radeon HD 8750M provides 28.80 GB/s of memory bandwidth, while the Quadro K620M provides only 16.02 GB/s, a difference driven by the Radeon's 128-bit bus versus the Quadro's 64-bit bus. The memory capacity also differs: 1024 MB on the Radeon versus 2 GB on the Quadro.

Clock speeds favor the Quadro substantially. Its base clock is 1029 MHz versus 775 MHz on the Radeon, and its boost clock is 1124 MHz versus 825 MHz. The memory clock is also higher on the Quadro at 1001 MHz (2 Gbps effective) versus 900 MHz on the Radeon (1800 Mbps effective). The texture mapping unit count differs, with the Radeon having 24 TMUs and the Quadro having 16. Consequently, the texture fill rate is 19.80 GTexel/s on the Radeon versus 17.98 GTexel/s on the Quadro.

FP32 performance favors the Quadro at 863.2 GFLOPS versus the Radeon's 633.6 GFLOPS. Pixel rate also favors the Quadro at 8.992 GPixel/s versus 6.600 GPixel/s. The transistor counts differ (950 million for Radeon, 1,020 million for Quadro), as do transistor densities (12.3M vs 13.2M per mm²). The bus interfaces are entirely different: PCIe 3.0 x8 for the Radeon versus MXM-A (3.0) for the Quadro. The Quadro's TDP is listed at 30 W, while the Radeon's TDP is not specified. The Quadro uses an MXM Module slot width with no power connectors, and its display outputs are portable device dependent.

Head-to-Head Benchmarks

The only head-to-head benchmark available is the Geekbench OpenCL test, and the results are extremely close. The AMD Radeon HD 8750M scores 5970, while the NVIDIA Quadro K620M scores 5957, giving the Radeon a 0.2% victory. This is the sole benchmark in the dataset, and it determines that the Radeon wins the head-to-head comparison with 1 win against 0 for the Quadro.

The margin is so small that it falls within the range of run-to-run variation for most benchmark suites. Looking at the nearest rivals for each GPU provides context for this result. The Radeon HD 8750M's nearest rival, the NVIDIA Quadro K4000, scores 5982, which is 0.2% higher than the Radeon. The Quadro K620M's nearest rival, the AMD Radeon HD 8730M, scores 5955, which is essentially tied with the K620M at a 0% delta. The Intel UHD Graphics 730 sits just below the K620M at 5929, a 0.5% deficit.

The benchmark data indicates that the Radeon HD 8750M's wins are driven by its memory bandwidth advantage. The 128-bit bus provides 28.80 GB/s, which is nearly double the Quadro's 16.02 GB/s. In OpenCL workloads that are memory-bound, this bandwidth advantage can compensate for the Radeon's lower clock speeds and reduced FP32 throughput. The Quadro K620M, conversely, relies on its higher clocks and superior FP32 compute (863.2 GFLOPS) to close the gap, but it cannot overcome the memory bandwidth deficit in this particular test. The result is a statistical tie in performance, with the Radeon holding a nominal edge that would likely not be perceptible in real-world applications. Both GPUs sit at the 34th percentile among all GPUs, confirming that they occupy the same performance class, with the Radeon's average benchmark score of 5970 and the Quadro's 5957 reflecting their near-identical standing.