AMD Instinct MI100 vs NVIDIA GeForce RTX 3090 Ti Comparison

The AMD Instinct MI100 and NVIDIA GeForce RTX 3090 Ti represent two distinct philosophies in high-performance computing, and the benchmark data highlights a clear performance hierarchy. The only direct head-to-head benchmark available is Geekbench OpenCL, where the NVIDIA GeForce RTX 3090 Ti decisively outperforms the AMD Instinct MI100. The RTX 3090 Ti scores 174,441 points, while the MI100 scores 139,035 points, resulting in a delta of -20.3% for the AMD part. This single data point suggests a significant generational and architectural advantage for NVIDIA in a general-purpose compute workload, but it does not tell the entire story. The MI100, while trailing in this specific test, holds its own against its nearest rivals, and the two cards are built for different environments.

Head-to-Head Benchmarks

The Geekbench OpenCL result is the sole direct comparison point in the data, and it favors the NVIDIA GeForce RTX 3090 Ti by a substantial margin. The RTX 3090 Ti’s score of 174,441 is 20.3% higher than the MI100’s 139,035. This is not a marginal victory; it is a clear generational leap in raw compute throughput for this type of workload. The RTX 3090 Ti’s FP32 performance is listed at 40.00 TFLOPS, which is significantly higher than the MI100’s 23.07 TFLOPS. This raw shader output is likely the primary driver behind the Geekbench result, as OpenCL often scales with raw floating-point capability.

However, the MI100’s performance relative to its own peer group is notable. The AMD card’s average benchmark score of 139,035 places it in the 96th percentile of all GPUs, and it edges out the NVIDIA Tesla V100 PCIe 16 GB (138,063) by 0.7% and the Tesla V100 SXM2 32 GB (137,731) by 0.9%. It also leads the AMD Radeon PRO V620 (136,472) by 1.9% and the AMD Radeon Pro W6800X Duo (135,774) by 2.4%. This indicates that within its compute-focused lineage, the MI100 is a strong performer, but it is simply outclassed by the consumer-derived RTX 3090 Ti in this specific test.

The RTX 3090 Ti’s position in the standings is slightly different. Its average benchmark score is 131,938, which is lower than its Geekbench OpenCL score alone, suggesting other benchmarks in its aggregate pull the average down. Despite this, it sits in the 95th percentile of all GPUs. It is only 0.7% ahead of the NVIDIA L4 (131,072) but trails the NVIDIA RTX 4000 Ada Generation (135,218) by -2.4%, the NVIDIA A10M (135,230) by -2.4%, and the AMD Radeon PRO W6800 (135,396) by -2.6%. This shows that while the RTX 3090 Ti wins the direct comparison against the MI100, it is not the undisputed champion in its broader competitive set, particularly against more modern workstation cards.

Architecture Differences

The architectural gap between these two GPUs is vast, explaining the benchmark disparity. The AMD Instinct MI100 is built on the CDNA 1.0 architecture using the Arcturus chip, manufactured on a 7 nm process at TSMC. It packs 25,600 million transistors on a large 750 mm² die, resulting in a transistor density of 34.1M / mm². In contrast, the NVIDIA GeForce RTX 3090 Ti uses the Ampere architecture with the GA102 chip, fabricated on an 8 nm process at Samsung. It contains more transistors—28,300 million—on a smaller 628 mm² die, achieving a higher density of 45.1M / mm². This suggests NVIDIA’s design is more efficient in packing logic into a smaller space, while AMD’s approach uses a larger die to accommodate its compute units.

Memory architecture is another major differentiator. The MI100 utilizes 32 GB of HBM2 memory on a massive 4096-bit bus, delivering a bandwidth of 1.23 TB/s. This is a server-grade solution designed for high-bandwidth data movement. The RTX 3090 Ti uses 24 GB of GDDR6X on a 384-bit bus, providing 1.01 TB/s of bandwidth. While the RTX 3090 Ti’s bandwidth is lower, its GDDR6X memory runs at a much higher effective clock speed of 21 Gbps, whereas the MI100’s HBM2 runs at 2.4 Gbps effective. The MI100’s wider bus compensates for the slower clock, but the RTX 3090 Ti’s approach is more typical of consumer hardware.

The compute core configuration also diverges significantly. The MI100 has 7,680 shading units, 480 TMUs, and 64 ROPs. It has no dedicated RT cores or tensor cores, as it is purely a compute accelerator. The RTX 3090 Ti, however, has 10,752 shading units, 336 TMUs, and 112 ROPs. It also includes 84 RT cores and 336 tensor cores, making it a fully featured consumer GPU capable of ray tracing and AI acceleration. The MI100’s FP16 performance is listed at 46.14 TFLOPS (2:1 ratio), while the RTX 3090 Ti achieves 40.00 TFLOPS FP16 (1:1 ratio). This means the MI100 has a higher theoretical half-precision throughput, which could be advantageous in certain AI workloads despite the OpenCL deficit.

Where Each One Wins

Based on the data, the NVIDIA GeForce RTX 3090 Ti is the clear winner in the Geekbench OpenCL test, and its higher FP32 throughput (40.00 TFLOPS vs. 23.07 TFLOPS) suggests it will dominate general-purpose single-precision compute tasks. The RTX 3090 Ti also has the advantage of a full API stack, supporting DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4, making it a viable option for gaming and consumer-facing applications. Its display outputs (1x HDMI 2.1 and 3x DisplayPort 1.4a) further cement its role as a user-facing card.

The AMD Instinct MI100, conversely, is a datacenter-focused accelerator with "No outputs" for display. Its strengths lie in its memory subsystem: the 32 GB HBM2 capacity and 1.23 TB/s bandwidth exceed the RTX 3090 Ti’s 24 GB and 1.01 TB/s. For workloads that require large datasets to reside close to the compute units, such as certain scientific simulations or large language model inference, the MI100’s memory advantage could be critical. Its FP16 performance of 46.14 TFLOPS is also higher than the RTX 3090 Ti’s 40.00 TFLOPS, potentially giving it an edge in mixed-precision training scenarios. However, the lack of RT and tensor cores means it lacks the specialized hardware for ray tracing and some AI acceleration paths.

The power and physical footprint also point to different use cases. The MI100 has a TDP of 300 W with a dual-slot design, while the RTX 3090 Ti is a power-hungry 450 W part in a triple-slot form factor. The MI100’s lower power draw and dual-slot layout make it easier to deploy in dense server environments, whereas the RTX 3090 Ti requires more substantial cooling and power delivery, including a suggested 850 W PSU versus the MI100’s 700 W recommendation.

FAQ

Q: Which GPU has the higher Geekbench OpenCL score?

A: The NVIDIA GeForce RTX 3090 Ti scores 174,441, which is 20.3% higher than the AMD Instinct MI100’s score of 139,035.

Q: How does the AMD Instinct MI100 compare to its nearest rivals?

A: The MI100 leads the NVIDIA Tesla V100 PCIe 16 GB by 0.7%, the Tesla V100 SXM2 32 GB by 0.9%, the AMD Radeon PRO V620 by 1.9%, and the AMD Radeon Pro W6800X Duo by 2.4%.

Q: What are the memory capacities and types for each card?

A: The AMD Instinct MI100 has 32 GB of HBM2 memory, while the NVIDIA GeForce RTX 3090 Ti has 24 GB of GDDR6X memory.

Q: Does the NVIDIA GeForce RTX 3090 Ti support ray tracing?

A: Yes, the RTX 3090 Ti includes 84 RT cores and 336 tensor cores, which enable hardware-accelerated ray tracing and AI features, unlike the MI100 which has none.

Q: What is the power consumption difference between the two?

A: The AMD Instinct MI100 has a TDP of 300 W, while the NVIDIA GeForce RTX 3090 Ti has a significantly higher TDP of 450 W.

Q: Which GPU has a higher FP16 compute rating?

A: The AMD Instinct MI100 has an FP16 rating of 46.14 TFLOPS (2:1), which is higher than the NVIDIA GeForce RTX 3090 Ti’s 40.00 TFLOPS (1:1).

The Verdict

The data clearly indicates that the NVIDIA GeForce RTX 3090 Ti is the superior choice for raw compute performance in the Geekbench OpenCL benchmark, winning the only direct comparison by 20.3%. Its higher FP32 throughput, larger shading unit count, and full feature set make it a more versatile and powerful card for general-purpose tasks, including those that leverage its RT and tensor cores. For a user needing a do-everything card with display outputs and top-tier single-precision performance, the RTX 3090 Ti is the data-backed choice.

However, the AMD Instinct MI100 is not without merit. Its 32 GB HBM2 memory with 1.23 TB/s bandwidth offers a capacity and bandwidth advantage over the RTX 3090 Ti’s 24 GB GDDR6X, which is crucial for memory-bound workloads. Its higher FP16 throughput and lower power draw (300 W vs. 450 W) make it an attractive option for specific datacenter deployments where memory capacity and power efficiency are paramount, and where the lack of display outputs is irrelevant. The MI100’s performance against its own rivals (Tesla V100, Radeon PRO V620) is solid, showing it is a capable compute card in its own right.

Ultimately, the choice hinges on the application. The RTX 3090 Ti wins on speed and versatility, while the MI100 wins on memory capacity, bandwidth, and power efficiency. The benchmark results show a clear winner for general compute, but the MI100’s specialized memory architecture could be the deciding factor for specific scientific or AI workloads. The RTX 3090 Ti is the better all-rounder; the MI100 is the more specialized tool.

Specification Differences

The following specifications differ between the two cards:

• Process Node: AMD Instinct MI100 uses 7 nm (TSMC); NVIDIA GeForce RTX 3090 Ti uses 8 nm (Samsung).
• Transistors: MI100 has 25,600 million; RTX 3090 Ti has 28,300 million.
• Die Size: MI100 is 750 mm²; RTX 3090 Ti is 628 mm².
• Transistor Density: MI100 has 34.1M / mm²; RTX 3090 Ti has 45.1M / mm².
• Base Clock: MI100 is 1000 MHz; RTX 3090 Ti is 1560 MHz.
• Boost Clock: MI100 is 1502 MHz; RTX 3090 Ti is 1860 MHz.
• Memory Clock: MI100 is 1200 MHz (2.4 Gbps effective); RTX 3090 Ti is 1313 MHz (21 Gbps effective).
• Memory Size: MI100 has 32 GB; RTX 3090 Ti has 24 GB.
• Memory Type: MI100 uses HBM2; RTX 3090 Ti uses GDDR6X.
• Memory Bus Width: MI100 is 4096 bit; RTX 3090 Ti is 384 bit.
• Memory Bandwidth: MI100 is 1.23 TB/s; RTX 3090 Ti is 1.01 TB/s.
• Shading Units: MI100 has 7,680; RTX 3090 Ti has 10,752.
• TMUs: MI100 has 480; RTX 3090 Ti has 336.
• ROPs: MI100 has 64; RTX 3090 Ti has 112.
• RT Cores: MI100 has none; RTX 3090 Ti has 84.
• Tensor Cores: MI100 has none; RTX 3090 Ti has 336.
• Pixel Rate: MI100 is 96.13 GPixel/s; RTX 3090 Ti is 208.3 GPixel/s.
• Texture Rate: MI100 is 721.0 GTexel/s; RTX 3090 Ti is 625.0 GTexel/s.
• FP32 Performance: MI100 is 23.07 TFLOPS; RTX 3090 Ti is 40.00 TFLOPS.
• FP16 Performance: MI100 is 46.14 TFLOPS (2:1); RTX 3090 Ti is 40.00 TFLOPS (1:1).
• TDP: MI100 is 300 W; RTX 3090 Ti is 450 W.
• Slot Width: MI100 is dual-slot; RTX 3090 Ti is triple-slot.
• Power Connectors: MI100 uses 2x 8-pin; RTX 3090 Ti uses 1x 16-pin.
• Suggested PSU: MI100 is 700 W; RTX 3090 Ti is 850 W.
• Display Outputs: MI100 has none; RTX 3090 Ti has 1x HDMI 2.1 and 3x DisplayPort 1.4a.
• APIs: MI100 has N/A for DirectX, OpenGL, and Vulkan; RTX 3090 Ti supports DirectX 12 Ultimate, OpenGL 4.6, and Vulkan 1.4.
• Dimensions: MI100 is 267 mm long and 111 mm high; RTX 3090 Ti is 336 mm long, 140 mm high, and 61 mm wide.
• Release Date: MI100 launched on 2020-11-15; RTX 3090 Ti launched on 2022-01-26.
• Launch MSRP: MI100 has none listed; RTX 3090 Ti has a launch MSRP of 1,999 USD.