Dell OptiPlex 3090 M vs. Dell OptiPlex 7090 M
Comparison and Differences
Differences between Dell OptiPlex 3090 M and Dell OptiPlex 7090 M
Both computers, the Dell OptiPlex 3090 M and the Dell OptiPlex 7090 M, were released during the same year - 2021.
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 M as it is running a newer generation CPU. This is not to say that Dell OptiPlex 3090 M 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 7090 M is using the faster 3200 MT/s RAM. The Dell OptiPlex 3090 M is slower by supporting RAM speeds of up to 2933 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 Dell OptiPlex 7090 M has 6 USB ports. The Dell OptiPlex 3090 M is inferior in this regard and packs 5 USB ports. In any case, if you miss USB ports, you can always purchase a USB hub. What is nice about the Dell OptiPlex 7090 M, is that it has 1 USB 3.1 port(s) which allows transfer of up to 10Gb/s. Unfortunately, the Dell OptiPlex 3090 M 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 7090 M comes with 2 ports, while the Dell OptiPlex 3090 M has only 1. If you are planning to use multiple monitors, the Dell OptiPlex 7090 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 Dell OptiPlex 3090 M is better equipped as it comes with 1 SATA slot(s), while the Dell OptiPlex 7090 M has 0 slot(s).
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 M has 1 M.2 slots while the Dell OptiPlex 3090 M 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 3090 M comes with a decent 65 Watt PSU, but the Dell OptiPlex 7090 M has a more powerful one rated at 180 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.