To upgrade the GPU of OptiPlex 7040 SFF, a low-power, low-profile graphics card must be used. Currently, the most reasonable GPU option is AMD's Radeon RX 6400 low profile.

However, like many other business pre-built PCs, this model may have proprietary elements like the power supply, the chassis or the power connector, which can make it difficult for usersYes, you can upgrade Dell OptiPlex 9020 SFF for gaming with better processors, graphics card, memory, and storage devices. Faster RAM speeds permit your processor to access the data stored inside the memory faster. This is important for the overall speed of your system. The motherboard of the Dell OptiPlex 9020 SFF supports RAM speeds of up to 1600 MT/s. Wi-Fi Support

Unfortunately, the Dell OptiPlex 9020 SFF has no M.2 PCIe soket and you have to rely on the available SATA ports to connect your drives. The SATA port is one of the places where you can connect a stora gedevice. The Dell OptiPlex 9020 SFF comes with three SATA port(s). Not enough SATA ports might limit your options for additional storage devices. Think about your use case and decide if the SATA ports provided by this model will be sufficient. This model has a good price point, delivers decent FPS, and does not require any addtional hardware upgrades.Line in for microphone / stereo, Line out for headphones / speakers, Realtek ALC3220 High Definition Audio Codec, Realtek ALC3234 High Definition Audio Codec The HDMI port is another digital video port you can use to connect external display. It has very similar capabilities to the DisplayPort with few exceptions. However, the Dell OptiPlex 9020 SFF doesn't have one. This is not a problem if there is on-board DisplayPort. Broadcom NetXtreme 10/100/1000 PCIe Gigabit Networking Card (Optional), Dell Wireless 1540 miniPCIe WLAN card (802.11a/b/g/n) (Optonal), Dell Wireless 1540 PCIe WLAN card (802.11a/b/g/n) (Optional), Dell Wireless 7260 M.2 WLAN card (802.11ac) (Optional), Intel i217 LM Gigabit1 Ethernet LAN 10/100/1000