Dell OptiPlex 7000 M vs. HP ProDesk 400 G3 SFF
Comparison and Differences
Differences between Dell OptiPlex 7000 M and HP ProDesk 400 G3 SFF
If you are looking for a more modern desktop, then you should go with the Dell OptiPlex 7000 M which was released in 2022. The HP ProDesk 400 G3 SFF is older and entered production in 2016.
If you are looking for the smaller form factor the Dell OptiPlex 7000 M is the right one for you. It is smaller than the HP ProDesk 400 G3 SFF and will fit more easily under your desk.
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 OptiPlex 7000 M as it is running a newer generation CPU. This is not to say that HP ProDesk 400 G3 SFF 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 Dell OptiPlex 7000 M is using the faster 4800 MT/s RAM. The HP ProDesk 400 G3 SFF is slower by supporting RAM speeds of up to 2133 MT/s. Additionally, if you will be needing a lot of RAM, better go for the Dell OptiPlex 7000 M as it has the ability to run 64 GB of RAM. The HP ProDesk 400 G3 SFF can do a bit less at max 32 GB. Most of the times, this should be sufficient for the majority of users.
Ports
In total the Dell OptiPlex 7000 M has 9 USB ports. The HP ProDesk 400 G3 SFF is inferior in this regard and packs 8 USB ports. In any case, if you miss USB ports, you can always purchase a USB hub. What is nice about the Dell OptiPlex 7000 M, is that it has 2 USB 3.1 port(s) which allows transfer of up to 10Gb/s. Unfortunately, the HP ProDesk 400 G3 SFF 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.
DisplayPort is crucial for any desktop machine. It is good to see that both models are featuring DisplayPorts. However, the Dell OptiPlex 7000 M comes with 2 ports, while the HP ProDesk 400 G3 SFF has only 1. If you are planning to use multiple monitors, the Dell OptiPlex 7000 M is the better choice.
None of the models has an HDMI port. If your monitor supports only the HDMI interface, you will need to buy an adapter. Such adapters are cheap so nothing to worry about.
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 ProDesk 400 G3 SFF is better equipped as it comes with 2 SATA slot(s), while the Dell OptiPlex 7000 M has 0 slot(s).
If you want the fastest transfer speeds for your SSD, an M.2 interface is crucial. Thus, if the M.2 SSD slot is a mandatory requirement for you, go with the Dell OptiPlex 7000 M. Sadly, the HP ProDesk 400 G3 SFF has no such slot, and you will be forced to use the SATA interface instead.
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 180 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.