128GB of unified memory is a dream come true for local LLMs. VRAM has been the ultimate bottleneck for developers.
While this NVIDIA system is inferior from the point of view of the memory capacity, its main advantage is that the top models will have a bigger GPU, i.e. with 6144 or 5120 FP32 execution units, compared to 2560 for the AMD GPU (compared to the NVIDIA CPU, the AMD CPU has a better multi-threaded performance for legacy programs, and a much better multi-threaded performance for the applications that use AVX-512).
However, these top models with big GPUs will also be much more expensive than the competing AMD system, while also being much more expensive than a laptop or mini-PC with an equivalent discrete NVIDIA GPU (which has the disadvantage of having direct access only to a much smaller, even if faster, memory).
The memory interface is a little faster, but the greatest improvement is +50% in the memory capacity, both over the old Strix Halo and over NVIDIA Spark.
However, even the Strix Halo CPU was better than the NVIDIA/Mediatek CPU.
NVIDIA has only the advantage (in its more expensive variants) of a GPU equivalent with RTX 5070.
It remains to see which will be the prices of the NVIDIA Spark models with big GPUs, but the rumors are that they grow from around $3000 upwards, with the upper limit for 128 GB DRAM and uncut GPU being unknown yet.
It also remains to be seen whether the variants with the biggest GPU can use it effectively when having a rather low memory bandwidth for such a big GPU.