It is not outdated in form of the power of the system, it is outdated in form of the Hardware that Dell used on the mainboard. A custom USB Chipset often makes problems, know that well from my old machine. I bought a PCIe USB3.0 card to get around that problem (and still use it in my new system). If you have a free small PCIe slot, that could be an option.
I have this one, the "KTU3FR-4P", that should be this card (that product number is on the card picture). Oculus recommended it for the Rift, should also work with the Rift S.
Amazon.com: Inateck PCI-e to USB 3.0 (4 Ports) PCI Express Card and 15-Pin Power Connector, Red (KT4001): Computers & Accessories
Buy Inateck PCI-e to USB 3.0 (4 Ports) PCI Express Card and 15-Pin Power Connector, Red (KT4001): Everything Else - Amazon.com ✓ FREE DELIVERY possible on eligible purchases
www.amazon.com
I have this one, the "KTU3FR-4P", that should be this card (that product number is on the card picture). Oculus recommended it for the Rift, should also work with the Rift S.