NVIDIA GeForce RTX 3090 vs NVIDIA GeForce RTX 5080

For running models locally, priced in Canada. At 64k context the first runs 22 models fully in memory, the second 10.

In short

The NVIDIA GeForce RTX 3090 has more memory for models: 24 GB against 16 GB. At 64k context the NVIDIA GeForce RTX 3090 runs 22 of the models we track fully in memory and the NVIDIA GeForce RTX 5080 10; only the NVIDIA GeForce RTX 3090 holds Qwen 3.8 27B. On the models both run fully in memory, the NVIDIA GeForce RTX 3090 and the NVIDIA GeForce RTX 5080 are about as fast as each other (estimated). In Canada the NVIDIA GeForce RTX 3090 costs $2,800 at Amazon and the NVIDIA GeForce RTX 5080 $2,370 at Amazon: the NVIDIA GeForce RTX 5080 is $430 cheaper.

Updated . Speeds are estimates; how they are worked out.

Specifications

SpecNVIDIA GeForce RTX 3090NVIDIA GeForce RTX 5080
GPUGeForce RTX 3090GeForce RTX 5080
Memory24 GB GDDR6X16 GB GDDR7
Memory bus384-bit256-bit
Memory bandwidth936 GB/s960 GB/s
FP16 compute71 TFLOPS113 TFLOPS
SoftwareCUDACUDA
Board power350 W360 W
PCIe generationGen 4Gen 5
PCIe lanesx16x16

What each runs

Estimated decode speed with the most precise quant that fits each one est.

ModelNVIDIA GeForce RTX 3090NVIDIA GeForce RTX 5080
Qwen 3.8 27B28tok/sUD-Q4_K_Moffload
Qwen 3.6 27B24tok/sQ5_K_Moffload
Qwen 3.6 35B-A3B107tok/sUD-Q4_K_Moffload
Qwen 3.5 27B27tok/sQ4_K_Moffload
Gemma 4 26B-A4B72tok/sUD-Q5_K_Moffload
Qwen 3.5 35B-A3B107tok/sQ4_K_Moffload
GLM 4.7 Flash53tok/sQ4_K_Moffload
gpt-oss 20B86tok/sMXFP488tok/sMXFP4
Gemma 4 12B41tok/sQ8_042tok/sQ8_0
Qwen 3.5 9B50tok/sQ8_051tok/sQ8_0
Gemma 3 27B26tok/sQ4_K_Moffload
Ministral 3 14B27tok/sQ6_Koffload
Qwen3 14B25tok/sQ6_Koffload
DeepSeek R1 0528 Qwen3 8B32tok/sQ8_041tok/sQ4_K_M
Qwen3 8B32tok/sQ8_041tok/sQ4_K_M
Phi-4 14B24tok/sQ5_K_Moffload
Qwen 3.5 4B87tok/sQ8_089tok/sQ8_0
Ministral 3 8B32tok/sQ8_039tok/sQ5_K_M
Granite 4.2 8B29tok/sQ8_0offload
Gemma 4 E4B57tok/sQ8_059tok/sQ8_0
LFM2.5 8B-A1B81tok/sQ8_083tok/sQ8_0
Llama 3.1 8B38tok/sQ6_K39tok/sQ6_K
Qwen 3.5 122B-A10Boffloadwon't run
Gemma 4 31Boffloadoffload
Qwen3 Coder Nextoffloadwon't run
Mistral Small 4 119Boffloadoffload
Qwen3 Next 80B-A3Boffloadwon't run
Devstral Small 2 24Boffloadoffload
Nemotron 3.5 Lightning 30B-A3Boffloadoffload
Kimi Linear 48B-A3Boffloadoffload
Qwen3 Coder 30B-A3Boffloadoffload
Qwen3 32Boffloadoffload
Mistral Small 3.2 24Boffloadoffload
DeepSeek R1 Distill Qwen 32Boffloadoffload
DeepSeek V4 Flashwon't runwon't run
GLM 5.3 Flashwon't runwon't run
Qwen 3.8 Flash Nextwon't runwon't run
MiniMax M2.7won't runwon't run
Nemotron 3 Super 120B-A12Bwon't runwon't run
gpt-oss 120Bwon't runwon't run
GLM 4.5 Airwon't runwon't run
Llama 3.3 70Bwon't runwon't run

Questions

Which is better for local AI, the NVIDIA GeForce RTX 3090 or the NVIDIA GeForce RTX 5080?
Choose the NVIDIA GeForce RTX 3090 to run bigger models. Choose the NVIDIA GeForce RTX 5080 to spend less.
Which can run bigger models, the NVIDIA GeForce RTX 3090 or the NVIDIA GeForce RTX 5080?
At 64k context the NVIDIA GeForce RTX 3090 runs 22 of the models we track fully in memory and the NVIDIA GeForce RTX 5080 10; only the NVIDIA GeForce RTX 3090 holds Qwen 3.8 27B.
Which is faster for local AI, the NVIDIA GeForce RTX 3090 or the NVIDIA GeForce RTX 5080?
On the models both run fully in memory, the NVIDIA GeForce RTX 3090 and the NVIDIA GeForce RTX 5080 are about as fast as each other (estimated).
What is the price difference between the NVIDIA GeForce RTX 3090 and the NVIDIA GeForce RTX 5080?
In Canada the NVIDIA GeForce RTX 3090 costs $2,800 at Amazon and the NVIDIA GeForce RTX 5080 $2,370 at Amazon: the NVIDIA GeForce RTX 5080 is $430 cheaper.

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