Nvidia RTX Spark vs Dell Pro Max 18 Plus: Local AI Memory, Performance and Benchmarks

What Dell has actually proven​

StorageReview's UL Procyon AI Text Generation tests put the Pro Max 18 Plus, with its RTX PRO 5000 Blackwell (24GB GDDR7), at 185.1 tokens per second on Phi, 140.5 on Mistral and 119.7 on Llama 3. Time to first token was under 0.35 seconds on every model. StorageReview calls it the fastest laptop it has tested. That is a claim about one outlet's lab, not a universal ranking.

The price of that speed is portability. StorageReview lists the machine at 7.17 pounds with 3 hours 39 minutes of measured battery life, the shortest runtime in its laptop dataset. Those battery figures come from PCMark 10 Modern Office runs. Local inference is a much heavier sustained load, so plan on wall power for real sessions.

TechRadar says Dell's top configuration cost $9,245.52 at launch and now sells for almost $18,600. I could not corroborate that price history independently. StorageReview lists the tested system at $9,245 at review time, but treat the later figures as TechRadar's reporting.

What RTX Spark is, and what it claims​

The platform pairs a 20-core Arm-based Grace CPU with a Blackwell RTX GPU and up to 128GB of unified memory in a single package. Nvidia's headline claims are:

• Up to 1 petaflop of FP4 AI performance, 6,144 CUDA cores and up to 128 GB of shared memory.
• Local LLMs of about 120 billion parameters with a one-million-token context window.

These are vendor claims. Treat "128GB" as "up to". The line-up is not uniform:

• Laptops come in two variants, a 5,120-core GPU with an 18-core CPU capped at 64GB, and a 6,144-core GPU with a 20-core CPU and up to 128GB. Both are rated at 45 to 80W.
• Dell's XPS 16 Creator Edition starts at $3,799.99 for preorder, with the 18-core chip, 5,120-core GPU and 32GB of unified memory.
• Some base Surface and ProArt models offer just 24GB.

The petaflop figure needs a caveat. Microsoft's Surface footnotes describe it as theoretical FP4 performance using sparsity. TechRadar likewise calls it an upper limit that everyday workloads may not reach. It is not comparable to a tokens-per-second score.

Capacity versus speed​

Nvidia's case rests on memory. Dell's discrete GPU has 24GB of VRAM. Spark's pool is shared with the CPU, so larger models can load at all. StorageReview's own explainer makes the distinction: fit determines whether a model runs; the silicon determines how fast. Its leaderboard shows the same trade. The HP ZBook Ultra G1a, with up to 96GB of assignable unified memory, ran DeepSeek-R1 70B but trailed every RTX PRO machine on Procyon speed.

Spark's published numbers lean the same way:

• Nvidia's Windows-on-Arm porting guide lists a 256-bit LPDDR5 interface with 300 GB/s of bandwidth. TechRadar sets that against 896 GB/s for Dell's RTX PRO 5000.
• TechRadar also notes Spark's 6,144 CUDA cores against Dell's 10,496.
• Token generation is typically bandwidth-sensitive. That is general industry knowledge rather than a measured Spark result, but it is why the 300 GB/s figure matters.

The sensible expectation is that Spark may win on model size and efficiency, not on raw speed with models that fit in Dell's 24GB. That is an inference, not a finding.

What to watch after October 16​

StorageReview says three of the first Spark systems are confirmed for its lab, including the Dell XPS 16 Creator Edition and the HP OmniBook Ultra 16. It adds that they enter the rankings when its numbers are in. It also notes a Microsoft chart putting a 137-billion-parameter model at roughly 60 tokens per second on a Surface Laptop Ultra. StorageReview describes that as a vendor result it has not reproduced.

For a fair verdict, look for:

1. The same Procyon text-generation suite on Phi, Mistral and Llama 3, with matching software.
2. Which configuration was tested. A 24GB or 32GB unit is a different proposition from a 128GB one.
3. Larger-model results, such as 70B-class models, where Dell's 24GB cannot compete.
4. Battery life under inference load, not just office benchmarks.
5. Windows on Arm compatibility for your tools. Nvidia's porting guide exists because software needs to be ported.

Bottom line​

Dell holds the measured lead as of October 13. Spark's larger unified-memory ceiling could make bigger local models practical in a lighter, cooler machine. Nothing published yet shows it beating Dell's token rates. For IT buyers, the decision between the two is about which models you actually run, not which logo is on the lid.