Dell XPS 8940 vs. HP EliteDesk 800 G4 Tower
Comparison and Differences
Differences between Dell XPS 8940 and HP EliteDesk 800 G4 Tower
If you are looking for a more modern desktop, then you should go with the Dell XPS 8940 which was released in 2020. The HP EliteDesk 800 G4 Tower is older and entered production in 2018.
Both models have the same form factor, meaning reoughtly they have the same phiysical size and form.
Processor
Usually the newer the generation of the CPU, the better the performance and efficiency is. If your budget allows it, you should go with the Dell XPS 8940 as it is running a newer generation CPU. This is not to say that HP EliteDesk 800 G4 Tower is bad - it can still run some powerful CPUs, albeit being an older generation.
Memory
Both models have have equal amount of ram slots (4 RAM). Usually two RAM slots are more than enough for most cases. However, the count should be taken into account when planning how much and what combination of RAM you are going to need for your system.
None of the desktops has an advantage when it comes to the speed of the RAM being used. Both models support RAM speeds of up to 2666. Additionally, if you will be needing a lot of RAM, better go for the Dell XPS 8940 as it has the ability to run 128 GB of RAM. The HP EliteDesk 800 G4 Tower can do a bit less at max 64 GB. Most of the times, this should be sufficient for the majority of users.
Ports
In total the HP EliteDesk 800 G4 Tower has 11 USB ports. The Dell XPS 8940 is inferior in this regard and packs 10 USB ports. In any case, if you miss USB ports, you can always purchase a USB hub. It's great that both of the models have USB 3.1 ports which will allow you to exchange data with your peripherals at up to 10Gb/s. But if you need maximum connectivity, go with the HP EliteDesk 800 G4 Tower as it has 5 USB3.1 ports (the Dell XPS 8940 has 1).
DisplayPort is crucial for any desktop machine. It is good to see that both models are featuring DisplayPorts. However, the HP EliteDesk 800 G4 Tower comes with 2 ports, while the Dell XPS 8940 has only 1. If you are planning to use multiple monitors, the HP EliteDesk 800 G4 Tower is the better choice.
The Dell XPS 8940 comes with an HDMI port, while the HP EliteDesk 800 G4 Tower does not support the interface. Of course missing HDMI port is something that can be easily fixed with a good adapter (e.g. DisplayPort to HDMI).
SATA ports are placed on the system board and it is where you connect your HDD, SSD and Optical Disk Drives. More SATA slots will allow you to have more drives running at the same time. In this regard the HP EliteDesk 800 G4 Tower is better equipped as it comes with 4 SATA slot(s), while the Dell XPS 8940 has 3 slot(s).
An M.2 SSD can be several times faster than a SATA one. Thus, we are happy to see that both models support the M.2 interface. However, the HP EliteDesk 800 G4 Tower has 1 M.2 slots while the Dell XPS 8940 comes with just 1.
Make sure that the available M.2 slot supports the PCIe (also called NVMe) interface. This is important as there are M.2 slots which support only the inferior SATA III interface. For comparison, the SATA III interface has max speeds of 6Gb/s, while the PCIe 3.0 x4 will support speeds up to 32Gb/s!
Power Supply
Looking at the Power Supply Unit (PSU) of the two models we don't see any differences. For either of them you get a maximum power of 500 Watts. However be careful, many models have more than one power supply option. When buying your computer, it is a good idea to get a version with the most powerful PSU. This will potentially allow you to upgrade to a more powerful GPU for example.