Bad news: DGX Spark may have only half the performance claimed.

Posted by Dr_Karminski@reddit | LocalLLaMA | View on Reddit | 264 comments

Bad news: DGX Spark may have only half the performance claimed.

There might be more bad news about the DGX Spark!

Before it was even released, I told everyone that this thing has a memory bandwidth problem. Although it boasts 1 PFLOPS of FP4 floating-point performance, its memory bandwidth is only 273GB/s. This will cause major stuttering when running large models (with performance being roughly only one-third of a MacStudio M2 Ultra).

Today, more bad news emerged: the floating-point performance doesn't even reach 1 PFLOPS.

Tests from two titans of the industry—John Carmack (founder of id Software, developer of games like Doom, and a name every programmer should know from the legendary fast inverse square root algorithm) and Awni Hannun (the primary lead of Apple's large model framework, MLX)—have shown that this device only achieves 480 TFLOPS of FP4 performance (approximately 60 TFLOPS BF16). That's less than half of the advertised performance.

Furthermore, if you run it for an extended period, it will overheat and restart.

It's currently unclear whether the problem is caused by the power supply, firmware, CUDA, or something else, or if the SoC is genuinely this underpowered. I hope Jensen Huang fixes this soon. The memory bandwidth issue could be excused as a calculated product segmentation decision from NVIDIA, a result of us having overly high expectations meeting his precise market strategy. However, performance not matching the advertised claims is a major integrity problem.

So, for all the folks who bought an NVIDIA DGX Spark, Gigabyte AI TOP Atom, or ASUS Ascent GX10, I recommend you all run some tests and see if you're indeed facing performance issues.