Dell OptiPlex 7070 SFF vs. Dell OptiPlex 7090 SFF
Comparison and Differences
Differences between Dell OptiPlex 7070 SFF and Dell OptiPlex 7090 SFF
If you are looking for a more modern desktop, then you should go with the Dell OptiPlex 7090 SFF which was released in 2021. The Dell OptiPlex 7070 SFF is older and entered production in 2019.
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 Dell OptiPlex 7090 SFF as it is running a newer generation CPU. This is not to say that Dell OptiPlex 7070 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 Dell OptiPlex 7090 SFF is using the faster 3200 MT/s RAM. The Dell OptiPlex 7070 SFF is slower by supporting RAM speeds of up to 2666 MT/s. Additionally, if you will be needing a lot of RAM, better go for the Dell OptiPlex 7090 SFF as it has the ability to run 128 GB of RAM. The Dell OptiPlex 7070 SFF can do a bit less at max 64 GB. Most of the times, this should be sufficient for the majority of users.
Ports
In total the Dell OptiPlex 7070 SFF has 10 USB ports. The Dell OptiPlex 7090 SFF is inferior in this regard and packs 9 USB ports. In any case, if you miss USB ports, you can always purchase a USB hub. It's great that both of the models have USB 3.1 ports which will allow you to exchange data with your peripherals at up to 10Gb/s. But if you need maximum connectivity, go with the Dell OptiPlex 7090 SFF as it has 3 USB3.1 ports (the Dell OptiPlex 7070 SFF has 1).
DisplayPort is crucial for any desktop machine. It is good to see that both models are featuring DisplayPorts. However, the Dell OptiPlex 7090 SFF comes with 3 ports, while the Dell OptiPlex 7070 SFF has only 2. If you are planning to use multiple monitors, the Dell OptiPlex 7090 SFF is the better choice.
The Dell OptiPlex 7090 SFF comes with an HDMI port, while the Dell OptiPlex 7070 SFF 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 3 SATA slot(s). Keep in mind that having too few SATA slots might limit your options for connecting additional memory drives.
An M.2 SSD can be several times faster than a SATA one. Thus, we are happy to see that both models support the M.2 interface. However, the Dell OptiPlex 7090 SFF has 1 M.2 slots while the Dell OptiPlex 7070 SFF comes with just 1.
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 7070 SFF comes with a decent 200 Watt PSU, but the Dell OptiPlex 7090 SFF has a more powerful one rated at 300 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.