AMD Radeon RX 6600 XT vs NVIDIA GeForce RTX 3070 Mobile Comparison

FAQ

Q: Which GPU wins in the 3DMark Steel Nomad DX12 test?

A: The NVIDIA GeForce RTX 3070 Mobile wins decisively, scoring 2380 against 1804 for the AMD Radeon RX 6600 XT. That is a 24.2% lead for the NVIDIA part.

Q: Does the AMD card win any compute workloads?

A: Yes. In Passmark GPU Compute, the RX 6600 XT scores 7520 versus 6827 for the RTX 3070 Mobile, a 10.2% advantage. It also leads in Passmark G3D with 16461 versus 15309, a 7.5% margin.

Q: How do the two cards compare in raw memory bandwidth?

A: The RTX 3070 Mobile has a 256-bit bus and 448.0 GB/s bandwidth, while the RX 6600 XT uses a 128-bit bus and 256.0 GB/s. The NVIDIA part offers 75% more bandwidth on paper.

Q: Which GPU has the higher transistor count?

A: The RTX 3070 Mobile, built on GA104, packs 17,400 million transistors, versus 11,060 million for the RX 6600 XT's Navi 23 chip. The NVIDIA die is also larger at 392 mm² versus 237 mm².

Q: What is the average benchmark score for each card?

A: The RX 6600 XT averages 24442 points across the database, placing it in the 70th percentile of all GPUs. The RTX 3070 Mobile averages 20534 points, landing in the 65th percentile.

Q: In DirectX 9 and DirectX 11 legacy workloads, which card performs better?

A: The RX 6600 XT wins both. It leads Passmark DX9 by 21.3% (194 versus 160) and Passmark DX11 by 18.1% (163 versus 138).

Architecture Differences

The two GPUs come from different design schools. The RX 6600 XT uses AMD's RDNA 2.0 architecture on a 7 nm TSMC process, while the RTX 3070 Mobile uses NVIDIA's Ampere architecture on an 8 nm Samsung process. The process difference shows in transistor density: AMD achieves 46.7 million transistors per mm² versus 44.4 million for NVIDIA, despite the NVIDIA chip carrying far more transistors overall.

The RTX 3070 Mobile is the larger and more complex part. Its GA104 die measures 392 mm² and holds 17,400 million transistors. The Navi 23 in the RX 6600 XT is 237 mm² with 11,060 million transistors. The NVIDIA chip also carries more execution resources: 5120 shading units, 160 texture mapping units, and 80 ROPs, against 2048 shading units, 128 TMUs, and 64 ROPs for AMD. NVIDIA further adds 160 tensor cores and 40 RT cores, while AMD lists 32 RT cores and no tensor core equivalent.

Memory architecture differs sharply. The RTX 3070 Mobile uses a 256-bit bus with 448.0 GB/s bandwidth, while the RX 6600 XT uses a 128-bit bus with 256.0 GB/s. Both have 8 GB of GDDR6, but the NVIDIA memory subsystem is substantially wider. The RTX 3070 Mobile connects via PCIe 4.0 x16, whereas the RX 6600 XT uses PCIe 4.0 x8.

Clock behavior also diverges. The RX 6600 XT has a higher base clock at 1968 MHz and a boost of 2589 MHz, with a game clock of 2359 MHz. The RTX 3070 Mobile runs a 1110 MHz base and 1560 MHz boost. Despite lower clocks, the NVIDIA part reaches higher FP32 throughput at 15.97 TFLOPS, versus 10.60 TFLOPS for AMD, thanks to its larger shader count.

Power delivery and physical design contrast as well. The RX 6600 XT is a dual-slot desktop card rated at 160 W TDP, requiring a single 8-pin connector and a 450 W suggested PSU. The RTX 3070 Mobile is a mobile part at 115 W TDP, uses no external power connectors (portable device dependent), and has no fixed slot width or dimensions. Display outputs also differ: the AMD card offers 1x HDMI 2.1 and 3x DisplayPort 1.4a, while the NVIDIA mobile part's outputs are portable device dependent. Both support DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. The RX 6600 XT launched on 2021-07-29, while the RTX 3070 Mobile launched earlier on 2021-01-11. Both are end-of-life products.

Head-to-Head Benchmarks

The recorded data splits the two cards nearly evenly: each wins 5 of the 10 head-to-head tests. The RTX 3070 Mobile dominates in modern API workloads, while the RX 6600 XT takes the older and 2D-oriented tests.

The biggest win for the NVIDIA card is 3DMark Steel Nomad DX12, where it scores 2380 against 1804, a 24.2% margin. This is the largest single-test gap in the comparison. The RTX 3070 Mobile also wins Geekbench Vulkan with 86768 versus 72417, a 16.5% lead, and Geekbench OpenCL with 92939 versus 80503, a 13.4% lead. These three tests cover the most demanding and modern workloads in the set.

The RX 6600 XT counters with its largest win in Passmark G2D, scoring 912 versus 641, a 42.3% advantage. That is the largest margin for either card in any test. The AMD part also wins Passmark DX9 by 21.3% (194 versus 160) and Passmark DX11 by 18.1% (163 versus 138). In Passmark G3D, the RX 6600 XT takes a 7.5% lead with 16461 versus 15309. It also wins Passmark GPU Compute with 7520 versus 6827, a 10.2% margin.

The narrower contests go to NVIDIA. The RTX 3070 Mobile edges out the AMD card in Passmark DX12 by 4.7% (64 versus 61) and in Passmark DX10 by 3.5% (113 versus 109). These are close enough to be within run-to-run variation, but the direction is consistent: NVIDIA holds the newer API titles, AMD holds the legacy ones. The overall average benchmark score tells a slightly different story: the RX 6600 XT averages 24442 versus 20534 for the RTX 3070 Mobile, a difference that reflects AMD's strength in several Passmark subtests. However, the percentile ranks are close, 70th for AMD versus 65th for NVIDIA.

The Verdict

The data points to a clear split by workload. For modern DX12 and compute-heavy tasks, the RTX 3070 Mobile is the stronger choice. Its 24.2% lead in 3DMark Steel Nomad DX12 and 16.5% lead in Geekbench Vulkan show a substantial advantage in current-generation rendering paths. The NVIDIA card also has more raw resources: 5120 shading units, 448.0 GB/s bandwidth, and 15.97 TFLOPS FP32.

For legacy DirectX workloads and 2D performance, the RX 6600 XT is superior. Its 42.3% win in Passmark G2D and 21.3% win in DX9 indicate better compatibility or optimization for older titles. The AMD card also wins the overall Passmark G3D and GPU Compute tests, which are common in the database's aggregate scoring.

The RTX 3070 Mobile sits in the 65th percentile of all GPUs with an average score of 20534, while the RX 6600 XT sits in the 70th percentile with 24442. That aggregate ranking favors AMD, but the head-to-head modern workload tests favor NVIDIA. Users targeting current DX12 games should prefer the RTX 3070 Mobile. Users running older DirectX titles or valuing 2D and compute performance in the Passmark suite should prefer the RX 6600 XT. The desktop AMD card also offers fixed display outputs (1x HDMI 2.1, 3x DisplayPort 1.4a) and a 160 W TDP with a 1x 8-pin power connector, making it a self-contained desktop solution. The RTX 3070 Mobile is a portable device dependent part at 115 W, so its integration depends entirely on the laptop design.

Specification Differences

The two GPUs differ in nearly every major specification category. The RX 6600 XT uses a 7 nm TSMC process, while the RTX 3070 Mobile uses an 8 nm Samsung process. Transistor counts diverge heavily: 11,060 million for AMD versus 17,400 million for NVIDIA. Die size follows: 237 mm² versus 392 mm². Transistor density is close, 46.7M per mm² versus 44.4M per mm².

Clock speeds are reversed in character. The RX 6600 XT runs a 1968 MHz base and 2589 MHz boost, with a 2359 MHz game clock. The RTX 3070 Mobile runs 1110 MHz base and 1560 MHz boost. Memory clocks also differ: AMD lists 2000 MHz with 16 Gbps effective, NVIDIA lists 1750 MHz with 14 Gbps effective.

Memory bus width is a major differentiator: 128-bit for AMD, 256-bit for NVIDIA. Bandwidth follows at 256.0 GB/s versus 448.0 GB/s. Both have 8 GB GDDR6. Shading units: 2048 versus 5120. TMUs: 128 versus 160. ROPs: 64 versus 80. RT cores: 32 versus 40. Tensor cores: none versus 160. Pixel rate: 165.7 GPixel/s versus 124.8 GPixel/s. Texture rate: 331.4 GTexel/s versus 249.6 GTexel/s. FP32: 10.60 TFLOPS versus 15.97 TFLOPS. FP16: 21.21 TFLOPS (2:1) versus 15.97 TFLOPS (1:1).

TDP differs: 160 W for AMD versus 115 W for NVIDIA. Power connectors: 1x 8-pin versus none. Suggested PSU: 450 W for AMD, none listed for NVIDIA. Bus interface: PCIe 4.0 x8 versus PCIe 4.0 x16. Display outputs: 1x HDMI 2.1 and 3x DisplayPort 1.4a versus portable device dependent. The RX 6600 XT has dimensions of 190 mm length, 110 mm height, and 40 mm width; the RTX 3070 Mobile has none listed. Release dates differ: 2021-07-29 for AMD, 2021-01-11 for NVIDIA. The RX 6600 XT has a launch MSRP of 379 USD; the RTX 3070 Mobile has no listed MSRP.

Where Each One Wins

The RTX 3070 Mobile wins in modern graphics APIs. It leads 3DMark Steel Nomad DX12 by 24.2%, Geekbench Vulkan by 16.5%, and Geekbench OpenCL by 13.4%. It also takes narrower wins in Passmark DX12 (4.7%) and DX10 (3.5%). This card is the pick for DX12 gaming, Vulkan titles, and compute workloads measured by Geekbench. Its 448.0 GB/s bandwidth and 5120 shading units support that profile.

The RX 6600 XT wins in legacy DirectX and 2D tasks. It leads Passmark G2D by 42.3%, DX9 by 21.3%, and DX11 by 18.1%. It also wins Passmark G3D by 7.5% and GPU Compute by 10.2%. This card suits older DirectX libraries, general 2D acceleration, and the aggregate Passmark scoring that feeds its higher average benchmark score of 24442.

The overall split is 5 wins each. The RX 6600 XT holds the higher percentile rank (70th versus 65th) and the higher average score (24442 versus 20534). The RTX 3070 Mobile holds the larger margin in the most demanding modern test. For users who prioritize current-generation rendering and raw shader throughput, the NVIDIA part is the data-backed choice. For users who prioritize legacy API performance, 2D acceleration, and aggregate Passmark results, the AMD part leads.