Internal vs external SSD performance on Xbox

I was curious if there was any performance difference between the internal and external SSD on Xbox. I have a 2 TB external SSD and that’s where I run MSFS from, including a 192 GB rolling cache.

So I asked Grok and here’s the reply…

TL;DR - internal is 5-6 times faster. I’m in the process moving of moving my installation to the internal drive. I’ll report back if I notice any difference.

Yes, the internal SSD in the Microsoft Xbox Series X is faster than a standard external SSD (connected via USB). Here’s a breakdown of why, based on the console’s hardware and storage architecture:

Key Specifications and Performance Comparison

Internal SSD: The Xbox Series X features a custom 1TB NVMe SSD with raw sequential read speeds of up to 2.4 GB/s (gigabytes per second). However, due to the console’s proprietary compression technology (DirectStorage API and hardware decompression via the Xbox Velocity Architecture), the effective throughput for game loading can reach up to 4.8 GB/s. This enables extremely fast load times for next-gen games, often reducing wait times to seconds in titles like Forza Horizon 5 or Starfield. The internal SSD is directly connected via the console’s high-speed PCIe 4.0 interface, minimizing latency.

External SSD (USB-connected):

Standard external SSDs for the Xbox Series X connect via USB 3.1 or 3.2 ports, which are limited to a theoretical maximum of about 625 MB/s (0.625 GB/s) for USB 3.2 Gen 1 (often marketed as 5 Gbps). Real-world sustained speeds are typically 400–540 MB/s, depending on the drive (e.g., Samsung T7 or WD Black models). This is roughly 4–6 times slower than the internal SSD’s raw speeds. Load times for backward-compatible games (e.g., Xbox One titles) will be noticeably longer when played directly from an external SSD compared to the internal drive—tests show differences of 10–30 seconds in large open-world games like Assassin’s Creed: Origins.

I tried my usual stress test flight over NYC in a 172 with everything installed and didn’t really notice much difference. It may have had a few less momentary freezes, but the LOD and pop in didn’t change.

That said, it certainly wasn’t any worse. I may clear and rebuild the cache just to see what happens. I haven’t done that since the SU 4 beta came out.

I will say it seemed to load up faster. I only got to the scene with the Cirrus Jet before it was done, and I have over 1100 objects loaded.

This comparison seems a bit missleading or mixed up.

As far as I remember Msfs/2024, or any xbox Series optimized title, won’t run off an USB drive. The Xbox OS doesnt allow it.

So the tech spec of an usb ssd are irrelevant.

Last time i compared the specs between the internal SSD and the xbox plug-in SSD (not usb!) the specs were pretty much identical.

I run MSFS/2024 both off the internal and the 2TB plugin and have not been able to ever tell a difference.

If anyone else has a different experience, I’d be very interested to share it. It’s a topic I’ve considered a long time but ,as I mentioned, never managed to prove anything.

You may be right. When I posed the question to Grok, I simply asked for an internal vs external SSD comparison. I didn’t specify USB. I assumed it would understand I meant an expansion card.

I guess that assumption was incorrect. I didn’t really clue into the fact that it was comparing to a USB drive. That explains why I didn’t see any difference.

When worded correctly, it says this:

Does this include port and cable conduction speeds? While the actual NMVe or SSD card can transmit/process at those speeds, how does the above contribute to any restriction if any?