AI
Ember-1 delivers near-identical accuracy to Kimi K3 while running 3.4x faster
Fireworks Research's new model matches Kimi K3's problem-solving ability with significantly reduced reasoning overhead, though price advantage depends on which provider you choose.
The New Stack
Fireworks Research unveiled Ember-1 in September as a research preview, claiming it can replicate the performance of Moonshot's open-weight Kimi K3 model while requiring roughly 40% fewer reasoning tokens—a metric that directly affects billing since output tokens incur charges.
How the comparison stacked up#
An independent evaluation tested both models through OpenRouter on identical logic puzzles, infrastructure deployment scheduling, and probability problems—each run five times for consistency. Ember-1 solved 14 of 15 test cases perfectly, while Kimi K3 maintained a perfect 15-of-15 record. The sole Ember-1 failure was a minor rounding error on one probability calculation that didn't significantly impact the overall assessment.
The performance gap proved dramatic: Ember-1 completed all tests in roughly one-third the time Kimi K3 required. In raw speed, Ember-1 averaged under two minutes per test cycle, whereas Kimi K3 ranged from several minutes to nearly 20 minutes on some runs. Ember-1 also used 23% fewer reasoning tokens across all tests, slightly short of its 40% reduction claim.
The cost trade-off#
On Fireworks' endpoint, Ember-1 cost $2.48 for the entire test suite compared to Kimi K3's $3.26—a 24% savings. However, this advantage evaporates when Kimi K3 is accessed through cheaper third-party providers on OpenRouter, where it can be provisioned at $1 per million input tokens and $9 per million output tokens. At those rates, the same workload would cost $1.96, undercutting Ember-1.
The verdict#
Ember-1 emerges as the speed champion with comparable accuracy to Kimi K3, making it ideal for applications where latency matters. The cost picture is murkier: Ember-1 wins on premium-priced endpoints but loses to discounted Kimi offerings elsewhere. For users prioritizing faster responses over minimal expenditure, Ember-1 represents a clear upgrade. Those optimizing for pure cost at the expense of speed can still access cheaper Kimi K3 pricing through alternative providers.
