The 990 Pro Gen 4 NVMe SSD operates at PCIe Gen 1 speeds on the Z590 Aorus Xtreme motherboard. What issues are present?
The 990 Pro Gen 4 NVMe SSD operates at PCIe Gen 1 speeds on the Z590 Aorus Xtreme motherboard. What issues are present?
Hey everyone,
I’m experiencing an odd problem with my Gen 4 NVMe SSD Samsung 990 Pro. Despite the setup being compatible with Gen 4, it’s only showing PCIe Gen 1 speeds according to CrystalDiskInfo and Samsung’s tool.
Here’s what I’ve verified:
- The SSD is correctly placed in the Gen 4 slot (M2P_CPU)
- BIOS is set to Auto/Gen4 for PCIe link speed
- BIOS was recently updated
- CrystalDiskInfo indicates PCIe 1.0 x4 or x1
- SSD has been reseated
- Performance metrics look normal
- No PCIe risers or extenders are installed
Gigabyte mentioned:
> "It is normal that BIOS doesn’t display full PCIe 4.0 speed. Please check in Windows using CrystalDiskInfo."
However, when I run it in Windows, it still reports Gen 1 speeds (around 908MBPS). I’ve noticed that toggling the BIOS setting can sometimes switch it to Gen 4 (7000+ MBPS), but then it reverts back to Gen 1 on subsequent boots.
Anyone else have encountered this issue? Could it be related to the motherboard, BIOS, or the SSD itself? Thanks for any suggestions. 🙏
Welcome to the forums, newcomer!
Your system is running the Gigabyte Z590 AORUS XTREME motherboard with BIOS version F15d.
The SSD is correctly placed in the Gen 4 slot (M2P_CPU) and supports PCIe4.0x4 speeds as per the manual.
If you recently updated the BIOS to F15d, have you reset the CMOS after confirming the flash was successful?
When populating slots M2A_SB and/or M2M_SB, does the SSD display PCIe3.0x4 speeds?
You didn’t mention the power supply make and model, nor its age.
I reset the CMOS and the BIOS was updated right away. The PSU is a ROG STRIX 1000W, I haven't set the SSD to Gen 3 slot yet.
I'm not sure why it works after manual resets and restarts.
My PSU is ROG STRIX 1000W, BIOS updated when possible, but I haven't tried setting the SSD on Gen 3 yet.
I don't understand how it functions at Gen 4 speed—it reverts to Gen 1 on the next boot.
Reference links: https://ibb.co/bkt9jtK, https://ibb.co/JWGy21vD
Screenshots: https://imgbb.com/screenshot-2025-07-27-230730 and others
It's not related to grounding issues. I attempted to install the Gigabyte App Center today, but my PC crashed with a CRITICAL_PROCCESS_DIED message after it restarted on Gen 4 speed—it’s unusual. I removed another SSD and it still worked on Gen 1. I’m considering removing my XPG S70 blade from the PS5 to see if that affects the Gen 1 performance, possibly because of a 990 Pro issue I read about. Many people complained online about BSOD with this model, but few reported similar problems on Gen 1. I’ll attach screenshots of Crystal Disk Info and Magician when it ran on Gen 4.
I changed the 990 Pro SSD to my XPG S70 Blade and it continues to run at Gen 4 speed without any issues. I also moved the 990 Pro to Gen 3, so is the 990 Pro still problematic?
Hi
@popatim
I received the report and the problem persists, though it seems less frequent now. I've created a full video about it, which you can watch here:
https://www.youtube.com/watch?v=GSS6bt9AWus
There are similar issues listed in this forum thread:
https://forum-en.msi.com/index.php?threa...wk.409663/