DGX Spark (GB10, 128 GB) vs M3 Ultra (512 GB, 80-core GPU)
The DGX Spark (GB10, 128 GB) runs 103 of 110 open models at 4-bit or better, the M3 Ultra (512 GB, 80-core GPU) runs 109. Usable memory: about 122 GB against 384 GB. The M3 Ultra (512 GB, 80-core GPU) has more memory bandwidth (819 vs 273 GB/s), so models that fit both answer faster on it.
Data as of 2 November 2026. Speeds are estimates unless marked measured.
Running gpt-oss-120b
Runs
~61 tok/s
MXFP4 · 68 of 122 GB · reported
Runs
~101 tok/s
MXFP4 · 68 of 384 GB · ModelFit est.
Single-user decode speed, estimated. Fastest machines for this model
Memory
128 GB
memory
512 GB
memory
~122 GB
usable for a model
~384 GB
usable for a model
273 GB/s
memory bandwidth
819 GB/s
memory bandwidth
What it runs
103
of 110 models run at 4-bit or better
109
of 110 models run at 4-bit or better
Our pick
Q4_K_XL · ~28 tok/s our est.
Q8_0 · ~24 tok/s our est.
Largest current model that fits
125B at Q4_K_XL
320B at Q8_0
Popular models
Runs
MXFP4 · ~61 tok/s
Runs
MXFP4 · ~101 tok/s
Runs
MXFP4 · ~63 tok/s
Runs
MXFP4 · ~117 tok/s
Runs
Q8_0 · ~45 tok/s
Runs
Q8_0 · ~112 tok/s
Runs
Q4_K_M · ~11 tok/s
Runs
Q8_0 · ~22 tok/s
Runs
Q8_0 · ~52 tok/s
Runs
Q8_0 · ~85 tok/s
Runs
Q4_K_M · ~6.0 tok/s slow
Runs
Q6_K · ~11 tok/s
Runs
Q4_K_M · ~23 tok/s
Runs
Q4_K_M · ~41 tok/s
2-bit only
Q2_K · ~13 tok/s
Runs
Q8_0 · ~33 tok/s
Rent one by the hour
Use Change under a machine to pick another type, producer, model or variant. How the numbers are worked out