Asus Z690 Strix Gaming supports M.2 slots for storage expansion.
Asus Z690 Strix Gaming supports M.2 slots for storage expansion.
Hello! I own an Asus Strix Z690 gaming motherboard with an i9 12900k and an ASUS TUF 3090ti. While researching my board, I discovered that inserting an NVMe drive into the M.2_1 slot reduces the PCIe x16 lane to x8 instead of x16. My friend suggests keeping M.2_1 for a 1TB Samsung 970 EVO boot drive because it offers better speeds, even though the performance gain between x16 and x8 on the GPU isn’t significant. I currently have my 1TB Samsung 970 Evo in M.2_1 and a 2TB Samsung 970 EVO Plus in M.2_2. My main concerns are: 1. How much speed loss am I experiencing? 2. What drive setup would be best given this situation? From what I see, my system still performs well, but this configuration might not be the most optimal. Any advice would be really helpful!
For a gaming setup it's typically between 2-3% at most. Place it in slot 2, using slot 1 won't improve performance because both slots connect directly to the CPU and the SSD is Gen 3—so any difference between Gen 5 and Gen 3 won't matter. The resulting loss of 2-3% would be wasted effort.
Your graphics card supports PCIe 4.0 x16, matching PCIe 5.0 x8. In theory, you shouldn't notice a performance gap. Yet it feels off because your CPU likely needs at least 20 lanes for full x16 performance and an SSD should work with x4. I reviewed your motherboard manual and you're right about that. You might want to use software to verify the actual PCIe version and speed with the SSD in the M2_1 slot. The manual doesn't clearly explain how PCIe lanes are allocated. Also, it's unclear if a PCIe 5.0 SSD in M2_1 will drop to x8. This situation is quite confusing. It would be best not to expect any loss when using PCIe 4.0 devices.