HP EliteDesk 800 G4 SFF vs. Lenovo ThinkCentre M900 Small
Comparison and Differences
Differences between HP EliteDesk 800 G4 SFF and Lenovo ThinkCentre M900 Small
If you are looking for a more modern desktop, then you should go with the HP EliteDesk 800 G4 SFF which was released in 2018. The Lenovo ThinkCentre M900 Small is older and entered production in 2015.
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 EliteDesk 800 G4 SFF as it is running a newer generation CPU. This is not to say that Lenovo ThinkCentre M900 Small 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.
The HP EliteDesk 800 G4 SFF is using the faster 2666 MT/s RAM. The Lenovo ThinkCentre M900 Small is slower by supporting RAM speeds of up to 2133 MT/s. In addition, you will be able to install the same amount of RAM in both models, and most probably 64 GB of RAM will be enough for most people. However, if you will be needing more RAM, make sure to check other desktop models too.
Ports
In total the HP EliteDesk 800 G4 SFF has 11 USB ports. The Lenovo ThinkCentre M900 Small 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 HP EliteDesk 800 G4 SFF, is that it has 5 USB 3.1 port(s) which allows transfer of up to 10Gb/s. Unfortunately, the Lenovo ThinkCentre M900 Small 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.
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 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 3 SATA slot(s). Keep in mind that having too few SATA slots might limit your options for connecting additional memory drives.
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 HP EliteDesk 800 G4 SFF. Sadly, the Lenovo ThinkCentre M900 Small 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
Having a Power Supply Unit with high power rating is important, if you are going to use components which require extra power. The Lenovo ThinkCentre M900 Small comes with a decent 210 Watt PSU, but the HP EliteDesk 800 G4 SFF has a more powerful one rated at 250 Watts. Choosing either one depends on your specific requirements and use case. Also don't forget that some models might have more than one PSU option - try to always get the most powerful one, especially if you plan to upgrade to a powerful GPU.