AMD Radeon RX 6600 LE vs AMD Radeon RX 6900 XT Comparison

AMD Radeon RX 6600 LE vs AMD Radeon RX 6900 XT: a comparison of two RDNA 2.0 parts from the same Radeon RX 6000 series, but aimed at very different tiers of performance. The RX 6600 LE is a compact, efficient Navi 23 solution, while the RX 6900 XT is a flagship Navi 21 part with far more silicon. The recorded benchmark data shows a clear hierarchy, but the details of where each card wins and why matter for specific use cases.

Where Each One Wins

The RX 6900 XT wins every recorded head-to-head benchmark in the database. In the two tests where both cards appear, Geekbench OpenCL and Geekbench Vulkan, the RX 6900 XT dominates. The OpenCL test is the larger gap: the RX 6900 XT scores 187673 versus the RX 6600 LE's 69229, a delta of -63.1% for the smaller card. The Vulkan test narrows the gap somewhat, but the RX 6900 XT still leads with 148525 against 72428, a -51.2% delta. So for raw compute and general API performance, the RX 6900 XT is the definitive winner.

The RX 6600 LE does not win any recorded head-to-head test. However, its advantage lies elsewhere: in its efficiency and physical footprint. The RX 6600 LE has a TDP of 132 W, a dual-slot width, a length of 190 mm (7.5 inches), and requires a single 8-pin power connector with a suggested 300 W PSU. The RX 6900 XT, by contrast, has a TDP of 300 W, is triple-slot, extends to 267 mm (10.5 inches), needs two 8-pin connectors, and suggests a 700 W PSU. For systems where space and power delivery are constrained, the RX 6600 LE is the only viable option from the data.

The benchmark averages reinforce the split. The RX 6900 XT has an average benchmark score of 50951 across its many tests, while the RX 6600 LE has an average of 70829 across just two tests. The RX 6600 LE's average is higher only because its benchmark list is short and does not include the demanding PassMark or 3DMark tests that drag down the RX 6900 XT's average. In direct comparisons, the RX 6900 XT is consistently ahead.

Architecture Differences

Both cards are built on the same RDNA 2.0 architecture and the same 7 nm TSMC process, but they use different chips. The RX 6600 LE uses Navi 23, a smaller die at 237 mm² with 11,060 million transistors. The RX 6900 XT uses Navi 21, a much larger die at 520 mm² with 26,800 million transistors. The transistor density is slightly higher on the Navi 21 die at 51.5M per mm² versus 46.7M per mm² on Navi 23, reflecting a denser flagship layout.

The execution resources scale dramatically. The RX 6900 XT has 5120 shading units, 320 texture mapping units, 128 ROPs, and 80 ray tracing cores. The RX 6600 LE has 1792 shading units, 112 TMUs, 64 ROPs, and 28 ray tracing cores. This is a 2.9x difference in shading units, a 2.9x difference in TMUs, a 2x difference in ROPs, and a 2.9x difference in ray tracing cores. The memory subsystem follows suit: the RX 6900 XT has 16 GB of GDDR6 on a 256-bit bus with 512.0 GB/s bandwidth, while the RX 6600 LE has 8 GB on a 128-bit bus with 224.0 GB/s bandwidth.

Clock speeds are closer than the resource counts. The RX 6600 LE has a base clock of 1626 MHz, a boost of 2495 MHz, and a game clock of 2045 MHz. The RX 6900 XT has a base of 1825 MHz, a boost of 2250 MHz, and a game clock of 2015 MHz. The RX 6600 LE actually boosts higher, but the RX 6900 XT's massive resource advantage overwhelms that. The memory clocks differ: the RX 6600 LE runs at 1750 MHz (14 Gbps effective), while the RX 6900 XT runs at 2000 MHz (16 Gbps effective). The RX 6900 XT also has a wider PCIe interface at PCIe 4.0 x16 versus the RX 6600 LE's PCIe 4.0 x8.

The RX 6900 XT offers additional display outputs, including a USB Type-C port, while the RX 6600 LE has three DisplayPort 1.4a and one HDMI 2.1. Both support DirectX 12 Ultimate (12_2), OpenGL 4.6, and Vulkan 1.4. The RX 6900 XT's production status is end-of-life, while the RX 6600 LE is active.

The Verdict

The data points to a simple conclusion: the RX 6900 XT is the performance leader in every recorded head-to-head test. For anyone prioritizing raw compute and API performance, the RX 6900 XT is the choice. Its OpenCL score of 187673 and Vulkan score of 148525 are far beyond the RX 6600 LE's 69229 and 72428. The RX 6900 XT also has twice the memory (16 GB vs 8 GB) and more than double the bandwidth (512.0 GB/s vs 224.0 GB/s), which matters for high-resolution textures and large datasets.

The RX 6600 LE is for a different buyer. Its TDP of 132 W, dual-slot footprint, and 190 mm length make it suitable for small form factor builds or systems with modest power supplies. The RX 6900 XT's 300 W TDP, triple-slot width, and 267 mm length require a larger chassis and a 700 W PSU. The RX 6600 LE's single 8-pin connector versus the RX 6900 XT's two 8-pin connectors further underscores the installation difference.

The percentile ranking complicates the picture slightly. The RX 6600 LE sits at the 91st percentile of all GPUs, while the RX 6900 XT sits at the 86th. This is because the RX 6600 LE's average score of 70829 comes from two strong Geekbench results, while the RX 6900 XT's average of 50951 is pulled down by its PassMark results, which include low DirectX scores (e.g., 113 for DirectX 12, 167 for DirectX 10) and a G3D score of 26732. The RX 6900 XT's nearest rivals include the NVIDIA CMP 50HX (delta 1.6%), AMD Radeon RX Vega 64 (delta 1.9%), and NVIDIA GeForce RTX 5070 Ti (delta 2%), showing it competes with high-end parts despite its lower average.

The RX 6600 LE's nearest rivals are closer in performance: NVIDIA RTX A3000 Mobile (delta 1%), NVIDIA Quadro P6000 (delta 1.2%), and AMD Radeon Pro WX 8200 (delta 1.4%). This indicates the RX 6600 LE sits in a mid-range band, not a flagship tier. The verdict from the database: choose the RX 6900 XT for maximum performance, choose the RX 6600 LE for a compact, low-power build where the RX 6900 XT cannot physically fit or be powered.

FAQ

Q: Which card has a higher boost clock?

A: The AMD Radeon RX 6600 LE has a higher boost clock at 2495 MHz, while the AMD Radeon RX 6900 XT boosts to 2250 MHz. However, the RX 6900 XT has more shading units (5120 vs 1792), so its lower clock is offset by far more compute resources.

Q: What is the memory difference between the two cards?

A: The RX 6900 XT has 16 GB of GDDR6 on a 256-bit bus with 512.0 GB/s bandwidth, while the RX 6600 LE has 8 GB on a 128-bit bus with 224.0 GB/s bandwidth. The RX 6900 XT also runs its memory at 2000 MHz (16 Gbps effective) versus the RX 6600 LE's 1750 MHz (14 Gbps effective).

Q: How do they compare in Geekbench Vulkan?

A: The RX 6900 XT scores 148525 in Geekbench Vulkan, which is 51.2% higher than the RX 6600 LE's 72428. This is the smaller of the two head-to-head gaps, but still a decisive win for the RX 6900 XT.

Q: Are both cards on the same architecture?

A: Yes, both use RDNA 2.0 and are built on a 7 nm process at TSMC. They are part of the same Radeon RX 6000 series, but the RX 6600 LE uses the Navi 23 chip while the RX 6900 XT uses the Navi 21 chip.

Q: What is the power requirement for each card?

A: The RX 6600 LE has a TDP of 132 W and requires a 300 W PSU with a single 8-pin connector. The RX 6900 XT has a TDP of 300 W, needs a 700 W PSU, and uses two 8-pin connectors.

Q: Which card is still in production?

A: The RX 6600 LE has an active production status, while the RX 6900 XT is end-of-life. The RX 6600 LE was released on 2023-12-07, and the RX 6900 XT was released on 2020-10-27.

Head-to-Head Benchmarks

The database records two direct comparisons between these cards, and the RX 6900 XT wins both. The first is Geekbench OpenCL. The RX 6900 XT scores 187673, which is 63.1% higher than the RX 6600 LE's 69229. This is a massive gap, reflecting the RX 6900 XT's 5120 shading units and 23.04 TFLOPS of FP32 performance against the RX 6600 LE's 1792 shading units and 8.942 TFLOPS. The RX 6900 XT's FP16 performance is also much higher at 46.08 TFLOPS versus 17.88 TFLOPS for the RX 6600 LE.

The second test is Geekbench Vulkan. Here the RX 6900 XT scores 148525, which is 51.2% higher than the RX 6600 LE's 72428. The gap narrows relative to OpenCL, likely because Vulkan is more sensitive to driver efficiency and the RX 6600 LE's higher boost clock (2495 MHz vs 2250 MHz) helps close the resource gap. Still, the RX 6900 XT maintains a clear lead.

Beyond these two, the RX 6900 XT has additional benchmark results that the RX 6600 LE does not. Its PassMark G3D score is 26732, and its GPU Compute score is 14547. The RX 6900 XT also has a Geekbench Metal score of 177021 and a 3DMark Steel Nomad DX12 score of 4079. The RX 6600 LE has no equivalent scores in the database, so a direct comparison on those tests is not possible. The RX 6900 XT's PassMark DirectX results vary widely, from 113 (DirectX 12) to 279 (DirectX 11), but these are not comparable to the RX 6600 LE.

The RX 6900 XT's nearest rivals in the database include the NVIDIA CMP 50HX (1.6% behind) and AMD Radeon RX Vega 64 (1.9% ahead), while the RX 6600 LE's nearest rivals are the NVIDIA RTX A3000 Mobile (1% ahead) and NVIDIA Quadro P6000 (1.2% ahead). This places the RX 6900 XT in a higher performance tier despite its lower average score, which is skewed by the PassMark suite.

Specification Differences

The two cards differ in nearly every measurable specification except architecture, process node, and API support. Here are the fields where they diverge:

• Chip: Navi 23 (RX 6600 LE) vs Navi 21 (RX 6900 XT)
• Transistors: 11,060 million vs 26,800 million
• Die size: 237 mm² vs 520 mm²
• Transistor density: 46.7M / mm² vs 51.5M / mm²
• Base clock: 1626 MHz vs 1825 MHz
• Boost clock: 2495 MHz vs 2250 MHz
• Game clock: 2045 MHz vs 2015 MHz
• Memory clock: 1750 MHz (14 Gbps effective) vs 2000 MHz (16 Gbps effective)
• Memory size: 8 GB vs 16 GB
• Memory bus width: 128 bit vs 256 bit
• Memory bandwidth: 224.0 GB/s vs 512.0 GB/s
• Shading units: 1792 vs 5120
• TMUs: 112 vs 320
• ROPs: 64 vs 128
• Ray tracing cores: 28 vs 80
• Pixel rate: 159.7 GPixel/s vs 288.0 GPixel/s
• Texture rate: 279.4 GTexel/s vs 720.0 GTexel/s
• FP32 performance: 8.942 TFLOPS vs 23.04 TFLOPS
• FP16 performance: 17.88 TFLOPS (2:1) vs 46.08 TFLOPS (2:1)
• TDP: 132 W vs 300 W
• Slot width: Dual-slot vs Triple-slot
• Power connectors: 1x 8-pin vs 2x 8-pin
• Suggested PSU: 300 W vs 700 W
• Bus interface: PCIe 4.0 x8 vs PCIe 4.0 x16
• Display outputs: 1x HDMI 2.1, 3x DisplayPort 1.4a vs 1x HDMI 2.1, 2x DisplayPort 1.4a, 1x USB Type-C
• Dimensions: 190 mm x 110 mm x 40 mm (7.5 x 4.3 x 1.6 inches) vs 267 mm x 120 mm x 50 mm (10.5 x 4.7 x 2 inches)
• Production status: Active vs End-of-life
• Release date: 2023-12-07 vs 2020-10-27
• Launch MSRP: None recorded for the RX 6600 LE; the RX 6900 XT launched at 999 USD (stated once here as launch MSRP).