HP ProDesk 400 G6 Mini vs. HP ProDesk 600 G4 Mini
Comparison and Differences
Differences between HP ProDesk 400 G6 Mini and HP ProDesk 600 G4 Mini
If you are looking for a more modern desktop, then you should go with the HP ProDesk 400 G6 Mini which was released in 2020. The HP ProDesk 600 G4 Mini 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 HP ProDesk 400 G6 Mini as it is running a newer generation CPU. This is not to say that HP ProDesk 600 G4 Mini is bad - it can still run some powerful CPUs, albeit being an older generation.
Memory
Both models have have equal amount of ram slots (2 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.
The HP ProDesk 400 G6 Mini is using the faster 3200 MT/s RAM. The HP ProDesk 600 G4 Mini is slower by supporting RAM speeds of up to 2666 MT/s. Additionally, if you will be needing a lot of RAM, better go for the HP ProDesk 400 G6 Mini as it has the ability to run 64 GB of RAM. The HP ProDesk 600 G4 Mini can do a bit less at max 32 GB. Most of the times, this should be sufficient for the majority of users.
Ports
Both models have the same amount of USB ports for total count of 7. If this is not enough, using a USB hub is always a viable option. 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 ProDesk 600 G4 Mini as it has 4 USB3.1 ports (the HP ProDesk 400 G6 Mini has 2).
DisplayPort is crucial for any desktop machine. It is good to see that both models are featuring DisplayPorts. However, the HP ProDesk 600 G4 Mini comes with 2 ports, while the HP ProDesk 400 G6 Mini has only 1. If you are planning to use multiple monitors, the HP ProDesk 600 G4 Mini is the better choice.
The HP ProDesk 400 G6 Mini comes with an HDMI port, while the HP ProDesk 600 G4 Mini 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 slots are located on the motherboard and it is where SSD, HDD and Optical Disk Drives are connected. Each of the two models being compared have 1 SATA slot(s). Keep in mind that having too few SATA slots might limit your options for connecting additional memory drives.
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 ProDesk 600 G4 Mini has 1 M.2 slots while the HP ProDesk 400 G6 Mini 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 65 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.