Radeon RX 7900 GRE 16GB and RX 480 8GB Vulkan benchmarks llama.cpp

My XFX Radeon RX 7900 GRE 16GB Vram GPU struggles with models over 20B size. I added my Radeon RX 480 8GB Vram GPU to the system and ran a few benchmarks using llama.cpp Ubuntu Vulkan build 10453. https://preview.redd.it/xx5op8tvx4oh1.jpg?width=771&format=pjpg&auto=webp&s=0504b2218030f60a238bfa628bb0b5440a7c5a5c Radeon RX 480 8GB GDDR5: Bandwidth 256.0 GB/s RX 7900 GRE 16GB GDDR6: Bandwidth 576.0 GB/s Here are the models tested, in the order they appear in table: medgemma-27b-it-UD-Q6_K_XL.gguf Qwen3.8-27B-Q6_K.gguf Qwen3.8-27B-OBLITERATED-Q5_K_M.gguf Gemma4-26B-A4B-QAT-Uncensored-HauhauCS-Balanced-Q4_K_M.gguf (with Flash Attention) Gemma4-26B-A4B-QAT-Uncensored-HauhauCS-Balanced-Q4_K_M.gguf (without Flash Attention) Model Size (GiB) Params (B) FA pp512 (t/s) tg128 (t/s) Gemma3 27B Q6_K 22.09 27.01 On 25.91 ± 0.15 1.25 ± 0.00 Qwen35 27B Q6_K 21.30 27.32 On 55.19 ± 0.58 5.96 ± 0.00 Qwen35 27B Q5_K - Medium 18.18 27.32 On 68.54 ± 0.42 11.73 ± 0.05 Gemma4 26B.A4B Q4_K - Medium 15.63 25.23 On 321.98 ± 2.69 51.94 ± 0.10 Gemma4 26B.A4B Q4_K - Medium 15.63 25.23 Off 321.59 ± 3.46 52.03 ± 0.05 llama-bench -m /Gemma4-26B-A4B-QAT-Uncensored-HauhauCS-Balanced-Q4_K_M.gguf load_backend: loaded RPC backend from /llama-b10453/libggml-rpc.so ggml_vulkan: Found 2 Vulkan devices: ggml_vulkan: 0 = AMD Radeon RX 7900 GRE (RADV NAVI31) (radv) | uma: 0 | fp16: 1 | bf16: 0 | fp4: 0 | warp size: 64 | shared memory: 65536 | int dot: 1 | matrix cores: KHR_coopmat ggml_vulkan: 1 = AMD Radeon RX 480 Graphics (RADV POLARIS10) (radv) | uma: 0 | fp16: 0 | bf16: 0 | fp4: 0 | warp size: 64 | shared memory: 65536 | int dot: 0 | matrix cores: none load_backend: loaded Vulkan backend from /llama-b10453/libggml-vulkan.so load_backend: loaded CPU backend from /llama-b10453/libggml-cpu-haswell.so model size params backend ngl test t/s gemma4 26B.A4B Q4_K - Medium 15.63 GiB 25.23 B Vulkan -1 pp512 321.59 ± 3.46 gemma4 26B.A4B Q4_K - Medium 15.63 GiB 25.23 B Vulkan -1 tg128 52.03 ± 0.05 build: 3cb7ffb1a (10453) real 0m30.345s Without 2nd GPU RX 480: Only RX 7900 GRE 16GB model test t/s gemma4 26B.A4B Q4_K - Medium pp512 238.10 ± 2.48 gemma4 26B.A4B Q4_K - Medium tg128 37.93 ± 0.06 https://preview.redd.it/blsjpy8zx4oh1.png?width=695&format=png&auto=webp&s=3e76a73a04108bae0b9ee18782887aae31d0cd14 So 36% improvement for tg128 using dual GPU. Also RX 480 only got 1.8 t/s for tg128. submitted by /u/tabletuser_blogspot [link] [comments]

Related

• Llama.cpp ROCm 7.2->7.14 upgrade, Radeon 780m iGPU benchmarks: ROCm vs Vulkan
• Benchmarks: TensorSharp vs. llama.cpp
• Qwen3.8-Flash-Next + MTP on Strix Halo: Vulkan Runtime Notes

Source: r/LocalLLaMA | 2026-09-07