USB issues

Can anyone help with this? I'm having an issue with only a limited number of my USB devices working at once and I have to unplug stuff to get others to work. A real issue as I want to get more!

My understanding is that up to 127 devices can be connected but there is a limited number of EndPoints and variable quantities are used per device. I've read that the best solution for this is to use USB 2.0 where possible as USB 3.0 has less EndPoints but my motherboard only has USB 3.0 ports (Asus X99-S).

Is some sort of PCI USB 2.0 expansion card a solution or will this not help me? Here's what I have connected:

*USB wireless mouse

*USB wireless keyboard (I also have a charging cable for this connected as it's a rechargeable one)

*webcam

external USB 3.0 drive

*monitor (this is what the keyboard charging cable is connected to and I also have two LED strips powered via the monitors USB.

Audio interface (Komplete Audio 2)

Midi/Controller keyboard (Komplete Kontrol S61 MK2)

Another controller (AKAI FL Studio Fire)

Rift S headset

Xbox controller

WiFi receiver (Asus USB-ac68)

USB hub (devices connected to this are marked with an asterisk).

Don't think I have missed anything!

What seems to be max limit for you in terms of connected devices?

@horgen: It seems to depend on the device I'd say. For example I can drop the drive and the Komplete Kontrol keyboard and the AKAI controller will work but if I remove the AKAI and turn on the Komplete Kontrol it doesn't work, I need to remove another device as well. If I remove the Rift S though or don't use it after startup I can get both controllers working.

@bulby_g: Did you get any expansion cards with the mobo? Seems you have many internal ones you can use as well.

However the problem might be that you are using more than just what the chipset provides.