Compusemble from YouTube contends they have discovered that Starfield suffers from a large amount of traversal stuttering due to poor SSD utilization, even on the Best SSDs. The issue purportedly pertains to SSD optimization, with the game file system incessantly relying on very small block sizes and a low queue depth to stream assets into the game. Compusemble feels Starfield's reliance on this data transfer method causes the SSD to bottleneck the game, reaching 100% utilization with read speeds well under 1GB/s when traversal stutter occurs — even on a PCIe Gen 5 SSD.
The video shows Compusemble running through the city of Atlantis — one of Starfield's largest and most intensive cities, with monitoring software to see how the game's frame rate, GPU, and SSD behave in the city. As Compusemble's character strolled through the city, the frame rate dropped momentarily several times during the "benchmark run" due to traversal stuttering, causing GPU usage to drop to almost 0% due to the above-mentioned SSD bottlenecking issues. SSD usage was hitting 100% utilization several times, with peak read speeds spiking as little as 555MB/s during one of these periods. That's far beneath the peak speed capabilities of the SSD.
For reference, Compusemble used a Radeon RX 6950 XT and Ryzen 7 7700X with 32GB of memory, along with a Crucial T700 Gen 5 SSD, the fastest consumer SSD on the market just a few months ago. So there's very little reason to doubt it's the test system at fault here.
Starfield's intrinsic use of low queue depths and small block sizes is very unusual. Compusemble reports that many games today read from storage drives in large block sizes to hit SSDs where they perform best. For instance, Microsoft recommends a block size range anywhere between 32-64k and very high queue depths for DirectStorage support. Starfield does not have DirectStorage support, but you don't need to optimize a game with Microsoft's storage API to make it work with this more appropriate IO workload.
Sadly, there's no real way at this time to prevent traversal stuttering in Starfield. Even on the low-quality preset, the game suffers from SSD-bound traversal stuttering issues. Hopefully, Bethesda will discover this problem and figure out how to optimize the game better for SSDs.