Dell OptiPlex 9020M vs. HP ProDesk 400 G6 Mini
Comparison and Differences
Differences between Dell OptiPlex 9020M and HP ProDesk 400 G6 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 Dell OptiPlex 9020M is older and entered production in 2013.
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 Dell OptiPlex 9020M 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 Dell OptiPlex 9020M is slower by supporting RAM speeds of up to 1600 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 Dell OptiPlex 9020M can do a bit less at max 16 GB. Most of the times, this should be sufficient for the majority of users.
Ports
In total the HP ProDesk 400 G6 Mini has 7 USB ports. The Dell OptiPlex 9020M is inferior in this regard and packs 6 USB ports. In any case, if you miss USB ports, you can always purchase a USB hub. What is nice about the HP ProDesk 400 G6 Mini, is that it has 2 USB 3.1 port(s) which allows transfer of up to 10Gb/s. Unfortunately, the Dell OptiPlex 9020M has no such port, thus restricting your transfer speeds significantly. For people who want to use external drives on regular basis, this might be an issue.
The DisplayPort is usually the more popular video port used with desktops and laptops, while the HDMI is used predominantly in consumer electronics. That's why, it is good to see that both of the models come with a DisplayPort.
The HP ProDesk 400 G6 Mini comes with an HDMI port, while the Dell OptiPlex 9020M 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.
When your goal is to have the fastest SSD transfer speeds, an M.2 interface is crucial. Thus, it is good that both models have M.2 SSD slots. Today M.2 SSDs are not much more expensive than the average SATA drives, so it really does not make sense to invest in SATA drives anymore.
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.