NVIDIA B300 SXM6 AC vs NVIDIA GeForce RTX 4070 Mobile Comparison

Where Each One Wins

The recorded benchmark data contains a single head-to-head comparison between the NVIDIA B300 SXM6 AC and the NVIDIA GeForce RTX 4070 Mobile. In that test, the Geekbench OpenCL workload, the B300 SXM6 AC delivers a score of 369831 against the RTX 4070 Mobile's 109197. This represents a 238.7% advantage for the server part, and it is the only direct comparison available in the database.

Looking beyond the single head-to-head test, the B300 SXM6 AC also holds a commanding position in the broader benchmark distribution. Its average benchmark score of 369831 places it in the 100th percentile of all GPUs tracked by the database. The nearest competitor to the B300 SXM6 AC is the NVIDIA B200, which averages 345482, a 7% gap. The NVIDIA H200 NVL trails by 10.4% at 334891, while the AMD Instinct MI300X sits 16.3% behind at 317994. The NVIDIA L40S is the furthest of the listed rivals, 25% back at 295763.

The RTX 4070 Mobile, by contrast, shows a much broader benchmark profile with nine recorded tests across Geekbench and Passmark suites. Its average benchmark score is 27435, placing it in the 73rd percentile. The mobile part's nearest rivals are tightly clustered: the AMD Radeon RX 6700 XT scores 27425 (0% delta), the NVIDIA GeForce RTX 3090 scores 27565 (-0.5% delta), the NVIDIA RTX PRO 4000 Blackwell scores 27135 (1.1% delta), and the AMD Radeon Pro Vega 20 scores 27839 (-1.5% delta). This indicates the RTX 4070 Mobile performs in a narrow band around its average, with no rival in its immediate vicinity exceeding a 1.5% difference.

The B300 SXM6 AC wins the only direct comparison, and its percentile ranking confirms it sits at the very top of the database's GPU hierarchy. The RTX 4070 Mobile, while competitive among its own peers, occupies a mid-to-upper tier at the 73rd percentile. The use-case split is therefore clear: the server accelerator dominates in raw compute throughput, while the mobile part has a wider range of recorded test results across different API and workload types, but none that approach the server part's scores.

Architecture Differences

The two GPUs come from fundamentally different branches of NVIDIA's product tree. The B300 SXM6 AC uses the GB110 chip built on the Blackwell Ultra architecture, belonging to the Server Blackwell (Bxx) generation. The RTX 4070 Mobile uses the AD106 chip on the Ada Lovelace architecture, part of the GeForce 40 Mobile generation. Both are manufactured on a 5 nm process at TSMC, but the similarity ends there.

The B300 SXM6 AC integrates 208,000 million transistors on a 1628 mm² die, giving a transistor density of 127.8 million per mm². The RTX 4070 Mobile integrates 22,900 million transistors on a 188 mm² die, with a density of 121.8 million per mm². The die size difference is substantial: the server part's die is roughly 8.7 times larger by area and carries about 9.1 times more transistors.

Memory architecture differs completely. The B300 SXM6 AC uses 288 GB of HBM3e on an 8192-bit bus, delivering 8.19 TB/s of bandwidth. The RTX 4070 Mobile uses 8 GB of GDDR6 on a 128-bit bus, providing 256.0 GB/s. The bandwidth gap is enormous: the server part offers roughly 32 times the memory bandwidth of the mobile part.

Compute resources follow a similar pattern. The B300 SXM6 AC has 18,944 shading units, 592 texture mapping units, and 24 raster output units. It also carries 592 tensor cores. The RTX 4070 Mobile has 4,608 shading units, 144 TMUs, 48 ROPs, 36 RT cores, and 144 tensor cores. The server part has about 4.1 times more shading units and 4.1 times more tensor cores, though the mobile part has twice the ROP count.

Clock behavior differs as well. The B300 SXM6 AC runs at a 1665 MHz base clock and a 2032 MHz boost clock. The RTX 4070 Mobile runs at 1395 MHz base and 1695 MHz boost. Despite the lower clocks, the mobile part achieves a higher pixel rate: 81.36 GPixel/s versus 48.77 GPixel/s for the server part, owing to its larger ROP count. The texture rate favors the server part: 1,202.9 GTexel/s versus 244.1 GTexel/s.

Power and physical specifications diverge sharply. The B300 SXM6 AC is an SXM Module with a 1100 W TDP and a suggested PSU of 1500 W. It uses PCIe 6.0 x16 and has no display outputs. The RTX 4070 Mobile is an IGP with a 115 W TDP, no power connectors, PCIe 4.0 x8, and portable-device-dependent display outputs. The mobile part supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4, while the server part lists N/A for all graphics APIs.

Head-to-Head Benchmarks

The only direct head-to-head measurement is the Geekbench OpenCL test. The B300 SXM6 AC scores 369831, while the RTX 4070 Mobile scores 109197. The delta is 238.7% in favor of the server part. This is the largest margin recorded in the database for any pair where both parts have been tested under the same workload.

To contextualize this margin, consider the B300 SXM6 AC's nearest rivals. The B200 scores 345482, which is 7% below the B300 SXM6 AC's 369831. The H200 NVL at 334891 is 10.4% behind. The MI300X at 317994 is 16.3% behind. The L40S at 295763 is 25% behind. The B300 SXM6 AC's lead over the RTX 4070 Mobile, at 238.7%, is an order of magnitude larger than its lead over any of these server-class competitors.

For the RTX 4070 Mobile, the 109197 OpenCL score sits well below its own average benchmark score of 27435, which is inflated by the Passmark tests (which produce scores like 19587 for G3D and 8399 for GPU compute). The OpenCL result is the mobile part's highest recorded score among the nine tests, but it still falls far short of the server part's result.

The B300 SXM6 AC has only one benchmark record, the OpenCL test, and it wins that test outright. The RTX 4070 Mobile has nine records, but in the one test where both parts appear, the mobile part loses by a wide margin. The data shows no test where the RTX 4070 Mobile wins against the B300 SXM6 AC.

FAQ

Q: Which GPU has the higher Geekbench OpenCL score?

A: The NVIDIA B300 SXM6 AC scores 369831, which is 238.7% higher than the NVIDIA GeForce RTX 4070 Mobile's 109197.

Q: How does the B300 SXM6 AC compare to its nearest rival, the NVIDIA B200?

A: The B300 SXM6 AC averages 369831, while the B200 averages 345482. This is a 7% advantage for the B300 SXM6 AC.

Q: What is the RTX 4070 Mobile's percentile ranking and closest competitor?

A: The RTX 4070 Mobile sits in the 73rd percentile of all GPUs. Its closest rival is the AMD Radeon RX 6700 XT, which scores 27425 versus the mobile part's 27435, a 0% delta.

Q: How much memory bandwidth does each GPU have?

A: The B300 SXM6 AC provides 8.19 TB/s from 288 GB of HBM3e on an 8192-bit bus. The RTX 4070 Mobile provides 256.0 GB/s from 8 GB of GDDR6 on a 128-bit bus.

Q: What are the TDP values for these two GPUs?

A: The B300 SXM6 AC has a TDP of 1100 W, while the RTX 4070 Mobile has a TDP of 115 W.

Q: Which GPU supports more graphics API features?

A: The RTX 4070 Mobile supports DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. The B300 SXM6 AC lists N/A for DirectX, OpenGL, and Vulkan.

Specification Differences

The two GPUs differ in nearly every measurable specification. The B300 SXM6 AC uses the GB110 chip with Blackwell Ultra architecture, while the RTX 4070 Mobile uses the AD106 chip with Ada Lovelace architecture. The server part has 208,000 million transistors on a 1628 mm² die, while the mobile part has 22,900 million transistors on a 188 mm² die.

Clock speeds differ: the B300 SXM6 AC runs at 1665 MHz base and 2032 MHz boost, while the RTX 4070 Mobile runs at 1395 MHz base and 1695 MHz boost. Memory clocks are nominally similar at 2000 MHz, but the effective data rates differ: 8 Gbps for the server part versus 16 Gbps for the mobile part.

Memory capacity and type diverge completely. The B300 SXM6 AC has 288 GB of HBM3e with an 8192-bit bus and 8.19 TB/s bandwidth. The RTX 4070 Mobile has 8 GB of GDDR6 with a 128-bit bus and 256.0 GB/s bandwidth.

Compute unit counts favor the server part: 18,944 shading units versus 4,608; 592 TMUs versus 144; 592 tensor cores versus 144. The RTX 4070 Mobile has more ROPs (48 versus 24) and adds 36 RT cores, which the B300 SXM6 AC does not list.

Pixel and texture rates reflect these differences. The B300 SXM6 AC achieves 48.77 GPixel/s and 1,202.9 GTexel/s. The RTX 4070 Mobile achieves 81.36 GPixel/s and 244.1 GTexel/s. FP32 and FP16 compute are both 76.99 TFLOPS for the server part and 15.62 TFLOPS for the mobile part.

Physical and interface specs differ: the B300 SXM6 AC is an SXM Module with PCIe 6.0 x16 and no display outputs, while the RTX 4070 Mobile is an IGP with PCIe 4.0 x8 and portable-device-dependent outputs. The server part has a 1100 W TDP and 1500 W suggested PSU, while the mobile part has a 115 W TDP and no power connectors.

Release dates differ: the B300 SXM6 AC was released in September 2025, while the RTX 4070 Mobile was released in January 2023. Both are listed as Active in production.

The Verdict

The data identifies the NVIDIA B300 SXM6 AC as the dominant compute part. Its single recorded benchmark score of 369831 places it at the 100th percentile, ahead of all four listed rivals by margins ranging from 7% to 25%. The 238.7% lead over the RTX 4070 Mobile in the head-to-head OpenCL test confirms that the server accelerator is in a separate performance class.

The RTX 4070 Mobile, with an average score of 27435 and a 73rd percentile ranking, is competitive within its own segment. Its nearest rivals all fall within 1.5% of its average score, indicating a tightly contested mobile and desktop GPU tier. The mobile part offers features the server part lacks: RT cores, a full graphics API stack including DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4, plus display outputs. It also has a higher pixel rate at 81.36 GPixel/s and a much lower TDP at 115 W versus 1100 W.

For compute-focused workloads, the B300 SXM6 AC is the clear choice based on the recorded data. For graphics rendering and portable applications, the RTX 4070 Mobile is the only one of the two with the necessary API support and output capabilities. The specifications support this split: the server part prioritizes memory bandwidth (8.19 TB/s) and FP32 throughput (76.99 TFLOPS), while the mobile part prioritizes ROP count (48), pixel rate (81.36 GPixel/s), and API compatibility. Neither part is a substitute for the other, and the benchmark data does not record any workload where the mobile part outperforms the server part.