Dell OptiPlex 990 MT vs. HP EliteDesk 800 G4 Tower
Comparison and Differences
Differences between Dell OptiPlex 990 MT and HP EliteDesk 800 G4 Tower
If you are looking for a more modern desktop, then you should go with the HP EliteDesk 800 G4 Tower which was released in 2018. The Dell OptiPlex 990 MT is older and entered production in 2011.
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 Tower as it is running a newer generation CPU. This is not to say that Dell OptiPlex 990 MT 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 Tower is using the faster 2666 MT/s RAM. The Dell OptiPlex 990 MT is slower by supporting RAM speeds of up to 1333 MT/s. Additionally, if you will be needing a lot of RAM, better go for the HP EliteDesk 800 G4 Tower as it has the ability to run 64 GB of RAM. The Dell OptiPlex 990 MT 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 EliteDesk 800 G4 Tower has 11 USB ports. The Dell OptiPlex 990 MT 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. What is nice about the HP EliteDesk 800 G4 Tower, is that it has 5 USB 3.1 port(s) which allows transfer of up to 10Gb/s. Unfortunately, the Dell OptiPlex 990 MT 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 HP EliteDesk 800 G4 Tower comes with 2 ports, while the Dell OptiPlex 990 MT has only 1. If you are planning to use multiple monitors, the HP EliteDesk 800 G4 Tower 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 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 4 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 Tower. Sadly, the Dell OptiPlex 990 MT 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 Dell OptiPlex 990 MT comes with a decent 265 Watt PSU, but the HP EliteDesk 800 G4 Tower has a more powerful one rated at 500 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.
Motherboard
