Dell OptiPlex 5040 SFF vs. Dell OptiPlex 5090 MT
Comparison and Differences
Differences between Dell OptiPlex 5040 SFF and Dell OptiPlex 5090 MT
If you are looking for a more modern desktop, then you should go with the Dell OptiPlex 5090 MT which was released in 2021. The Dell OptiPlex 5040 SFF is older and entered production in 2015.
If you are looking for the smaller form factor the Dell OptiPlex 5040 SFF is the right one for you. It is smaller than the Dell OptiPlex 5090 MT and will fit more easily under your desk.
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 5090 MT as it is running a newer generation CPU. This is not to say that Dell OptiPlex 5040 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 5090 MT is using the faster 3200 MT/s RAM. The Dell OptiPlex 5040 SFF is slower by supporting RAM speeds of up to 1600 MT/s. Additionally, if you will be needing a lot of RAM, better go for the Dell OptiPlex 5090 MT as it has the ability to run 128 GB of RAM. The Dell OptiPlex 5040 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. What is nice about the Dell OptiPlex 5090 MT, is that it has 3 USB 3.1 port(s) which allows transfer of up to 10Gb/s. Unfortunately, the Dell OptiPlex 5040 SFF 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 5090 MT comes with 4 ports, while the Dell OptiPlex 5040 SFF has only 2. If you are planning to use multiple monitors, the Dell OptiPlex 5090 MT is the better choice.
The HDMI video interface is broadly used and the majority of the external displays support it. Thus, it is nice to see that both models have this video interface. If you are going to use multiple monitors go with the Dell OptiPlex 5090 MT which has 2 ports. The Dell OptiPlex 5040 SFF has only 1 ports.
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 5090 MT is better equipped as it comes with 4 SATA slot(s), while the Dell OptiPlex 5040 SFF has 3 slot(s).
When your goal is to have the fastest SSD transfer speeds, an M.2 interface is crucial. Thus, it is good that both models have M.2 SSD slots. Today M.2 SSDs are not much more expensive than the average SATA drives, so it really does not make sense to invest in SATA drives anymore.
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 5040 SFF comes with a decent 180 Watt PSU, but the Dell OptiPlex 5090 MT has a more powerful one rated at 360 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
