The camera has the option within the menu to do a 3x3 display. You would go into the Menu> Camera 5 Menu> Grid Display. Pressing this and entering into the Menu will allow you to change the grid display from 3x3, 6x4 or 3x3+diagonal.
@jodyann11 Is there a choice for 3x3 grid on the 5D Mark IV?
The type of grid to be displayed is on tab 5 of the "Shoot" menu (first menu, white camera on red background).
I hope that you sppreciate this reply, as in the process of verifying it on my camera my viewfinder grid—only the viewfinder, not live-view—became stuck on 6x4 and nothing I know to do in the Shoot or Setup menus will return it to 3x3!
Hi. I'm having the exact same problem. Viewfinder screen stuck on 6X6 display. I'd like to set it to 3X3. The only setting I have been able to change is using the settings tab, turn the grid off which doesn't help. The grid changes work in live view on the LCD, but not in normal camera mode using the viewfinder. Have you had any luck/fixes? Thanks . ~SR
Did you read the earlier replies in the thread? Did you read the reply checked of as The Answer?
It appears that the only option for the viewfinder grid is on/off, ans shown in the wrench menu. The 3x3, cross grid, etc., are only available in in Live View. In other words the viewfinder grid has no options other than to enable/disable display of the grid. You can't set the number of grid lines.