Question ASUS ROG Strix B450-F Gaming motherboard specifies VGA config for single card where PCIE_X16_1 says 16X while PCIE_X16 says N/A, does it run as 16X?

[Warguard]

The motherboard specifies VGA configuration for single card where PCIE_X16_1 is running on 16X while PCIE_X16_2 says N/A, does N/A represent the same 16X speed if I place my GPU there? The motherboard in question is an ASUS ROG Strix B450-F GAMING.

 

[velocityg4]

If PCIE_X16_1 is set for x16 mode. PCIE_X16_2 is N/A (not available) and M.2_2 is N/A.
If PCIE_X16_1 is set for x8 mode. PCIE_X16_2 will operate in x4 mode and M.2_2 operates in x4 mode. x4 mode is the fastest option for PCIE_X16_2 as it shares x4 lanes with the M.2_2. There is no option for it to work in x16 or x8 mode.

 

[WaltzWorker]

No! This MB as with some boards (via the chipsets which are below the X570 [I think] ) share PCI lanes... This one seems to share PCIE_X16_2 with the M.2_2 connection AND SATA ports 5 & 6!!! So... If you have your GPU in PCI_X16_1 (slot one) then if you want it to run in X16 mode you can't put anything in PCIE_X16_2 slot. IF You Do - then the GPU will drop to X8, the 2nd slot will run at X4... M2_2 will be run but at X4 because of the sharing of PCI lanes. M.2_1 will be supported and depending upon the mode it runs will be X4 or will be supported/will run. IF you had an older CPU - the M.2_2 slot would be totally disabled if you have your GPU in X16_1 and an M.2 drive in M.2_1. and would not support anything in M.2_2. So then.. IF you place your GPU in PCIE_X16_2 your system will think you have a dual GPU setup... I'm not sure if it will run like that... Although it would run at X4 and expecting the first slot PCIE_X16_1 to run at X8.... Not sure your MB can run Please note manual page ix under "Storage": "-M.2_1 socket 3 with M key, Type 2242/2260/2280 (PCIE 3.0 x4 and SATA modes) storage devices support" which leads to: " When M.2_1 Socket 3 is operating in SATA or PCIE mode, SATA6G_5/6 ports will be disabled." This means that if you use M.2_1 You will also loose SATA6G_5 & SATA6G_6 physical sata ports on the motherboard as well.

 

[Warguard]

Thank you all so much for the answers and clarification.

I gues that confirms it as I tried putting the GPU in the PCIE_X16_2 slot while PCIE_X16_1, PCIE_X16_3 and M.2_2 are vacant and somehow managed to have GPU-Z report it within the bus interface field as PCIE X16 3.0 @ X4 1.1 (even if I set NB for PCIE_X16_2 manually to GEN 3 it still shows 1.1).