Dell OptiPlex 990 SFF vs. HP EliteDesk 800 G1 USDT
Comparison and Differences
Differences between Dell OptiPlex 990 SFF and HP EliteDesk 800 G1 USDT
If you are looking for a more modern desktop, then you should go with the HP EliteDesk 800 G1 USDT which was released in 2013. The Dell OptiPlex 990 SFF 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 G1 USDT as it is running a newer generation CPU. This is not to say that Dell OptiPlex 990 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 (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 G1 USDT is using the faster 1600 MT/s RAM. The Dell OptiPlex 990 SFF 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 G1 USDT as it has the ability to run 32 GB of RAM. The Dell OptiPlex 990 SFF can do a bit less at max 16 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 10. If this is not enough, using a USB hub is always a viable option. None of the desktop models has a USB 3.1 port (10Gb/s), so if you need a fast connection to your peripherals, like external Solid State Drive, you will need to look elsewhere.
DisplayPort is crucial for any desktop machine. It is good to see that both models are featuring DisplayPorts. However, the HP EliteDesk 800 G1 USDT comes with 2 ports, while the Dell OptiPlex 990 SFF has only 1. If you are planning to use multiple monitors, the HP EliteDesk 800 G1 USDT 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 Dell OptiPlex 990 SFF is better equipped as it comes with 3 SATA slot(s), while the HP EliteDesk 800 G1 USDT has 1 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 HP EliteDesk 800 G1 USDT. Sadly, the Dell OptiPlex 990 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
Having a Power Supply Unit with high power rating is important, if you are going to use components which require extra power. The HP EliteDesk 800 G1 USDT comes with a decent 180 Watt PSU, but the Dell OptiPlex 990 SFF has a more powerful one rated at 240 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
