GPUs / AMD

RX 6900 XT

Memory
GDDR6
Bus
256-bit
Published peak
512 GB/s
Capacity
16 GB

Measured

Read
502.8GB/s
Write
464.0GB/s
Copy
426.9GB/s
Random
76.4GB/s
Latency
245ns
Sustain
426.9GB/s

Medians of 1 verified run from 1 operator. Read reaches 98 % of the published peak.

Local AI speed

ModelParameters4-bit, tokens/s8-bit, tokens/s
Llama 3.1 8B8.03B≤ 125≤ 63
Qwen 2.5 14B14.7B≤ 68≤ 34
gpt-oss-20b21B, 3.6B active≤ 279Does not fit
Mistral Small 24B24B≤ 42Does not fit
Qwen 2.5 32B32.5BDoes not fitDoes not fit
Llama 3.3 70B70.6BDoes not fitDoes not fit
gpt-oss-120b117B, 5.1B activeDoes not fitDoes not fit
Upper bounds: median read ÷ bytes read per token. Mixture-of-experts models read only their active experts. Fit checks weights against the 16 GB configuration; the KV cache needs room on top.

Top operators

#OperatorScoreReadDate
1OP-38081982.0502.8 GB/s2026-09-28

Full RX 6900 XT leaderboard