

Is the DGX Spark worth the money?
I've seen a lot of DGX Spark discussions here focused on inference performance, and yeah, if you compare it to 4x 3090s for running small models, the DGX loses both in price and performance.
The Spark actually excels for prototyping
Let me break it down:
I just finished CPT on Nemotron-3-Nano on a ~6B tokens dataset.
I spent about a week on my two Sparks debugging everything: FP32 logit tensors that allocated 34 GB for a single tensor, parallelization, Triton kernel crashes on big batches on Blackwell, Mamba-2 backward pass race conditions, causal mask waste, among others. In total I fixed 10+ issues on the Sparks.
The Sparks ran stable at 1,130 tokens/sec after all patches. ETA for the full 6B token run? 30 days!!!. Not viable for production. Instead I tried the same setup on a bigger Blackwell GPU, the B200, actually 8x B200.
Scaling to 8x B200
When I moved to 8x B200 on Verda (unbelievable spot pricing at €11.86/h), the whole setup took about 1 hour. All the patches, hyperparameters, and dataset format worked identically as in the DGX, I just needed to scale. The Spark's 30-day run finished in about 8 hours on the B200s. 167x faster (see image).
For context, before Verda I tried Azure, but their quota approval process for high-end GPU instances takes too long. Verda instead let me spin up immediately on spot at roughly a quarter of what comparable on-demand instances cost elsewhere.
Cost analysis (see image)
If I had prototyped directly on cloud B200s at on-demand rates it would be about ~€1,220 just for debugging and getting the complete model-dataset properly set up. On the Spark? €0 cost as the hw is mine.
Production run: €118. Total project cost: €118.
Cloud-only equivalent: €1,338 (if I chose the same setup I used for training). That's 91% less by starting first on the DGX.
Ok, also the Spark has a price, but ~€1,200 saved per prototyping cycle, the Spark pays for itself in about 6-7 serious training projects. And most importantly, you'll never get a bill while prototyping, figuring out the setup and fixing bugs.
The honest opinion
The DGX Spark is not an inference machine and it's not a training cluster. It's a prototyping and debugging workstation. If you're doing large training work and want to iterate locally before burning cloud credits, it makes a lot of sense. If you just want to run LLMs for single-turn or few-turns chatting, buy something like the 3090s or the latest Macs.
For anyone interested in more details and the process from starting on the DGX and deploying to the big Blackwell GPUs, you can find the whole research here.
Happy to answer any questions about the Spark, the 2-node cluster setup, and B200/B300 Blackwell deployment.
