Dell OptiPlex 3040M vs. Dell OptiPlex 5040 MT

Comparison and Differences

ModelDell OptiPlex 3040MDell OptiPlex 5040 MT
Form factorMicroMini Tower
CPU optionsIntel Gen6 i3/i5; Pentium; Celeron; Intel Gen6 i3/i5/i7
ChipsetIntel H110Intel Q170
RAM slots24
RAM speed16001600
RAM max1616
USB Ports(4x) USB-A 3.0; (2x) USB-A 2.0; (6x) USB-A 3.0; (4x) USB-A 2.0;
Video PortsDisplay Port 1.2; HDMI 1.4;(2x) Display Port 1.2; HDMI 1.4;
Other PortsRJ45; Headset; Line-Out; Serial; (2x) PS2; RJ45; Headset; Line-Out;
Optional PortsWiFi antenna; Serial+PS2; Serial; VGA;VGA; Media Card Reader;
SATA ports14
PCIeN.A.PCIe 3.0 x16; PCIe 3.0 x16 (wired x4); PCIe 3.0 x1; PCI;
M.2 slotsM.2 2230 (WiFi/BT)M.2 2280 M-key (PCIe 3.0 x4, SATA 3.0)
Drive bays2.5-inch3.5-inch/5.25-inch; (2x) 2.5-inch; 5.25-inch slim;
Hard DriveSATA max 1TB;SATA max 1TB;
PSU65 W240 W
Weight1.28 kg (2.82 lb)8.00 kg (17.64 lb)

The difference between Dell OptiPlex 3040M and Dell OptiPlex 5040 MT

Welcome to our page comparing the Dell OptiPlex 3040M vs. the Dell OptiPlex 5040 MT. Are you trying to choose between the two desktop computers unsure which one is more suitable for you? This page will try to highlight the differences between the two models: the Dell OptiPlex 3040M vs. Dell OptiPlex 5040 MT. Don't forget to also check the comparison table where you will find detailed specification.

Both computers, the Dell OptiPlex 3040M and the Dell OptiPlex 5040 MT, were released during the same year - 2015.

For some use cases size is important. If you are looking for the smaller form factor the Dell OptiPlex 3040M is the right one for you. It is smaller than the Dell OptiPlex 5040 MT and will fit easier under your desk.

The processor

The two models support the same generation of Intel Core processors. We think that the 6th generation Intel Core has enough power to execute all of the home and office tasks that most people will care to do.


The Dell OptiPlex 5040 MT has 4 RAM slots while the Dell OptiPlex 3040M has only 2 slots. Of course this is not something to worry about. Just make sure you take it into account when planning how much RAM will your system be using. None of the desktops has an advantage when it comes to the speed of the RAM being used. Both models support RAM speeds of up to 1600. You will be able to install the same amount of RAM in both models, and most probably 16 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.


None of the desktop models has a USB 3.1 port (10Gb/s), so if you need a fast connection to your peripherals you will need to look at other models.

DisplayPort is crucial for any desktop machine. It is good to see that both models are featuring DisplayPorts. However, the Dell OptiPlex 5040 MT comes with 2 ports, while the Dell OptiPlex 3040M has only 1.

In case your monitor supports HDMI only, you will be happy to hear that both models come with an HDMI port.

SATA slot is where SSD, HDD and Optical Disk Drives are connected. More SATA slots will allow you to have more Disk Drives running at the same time. In this regard the Dell OptiPlex 5040 MT is better equipped as it comes with 4 SATA slots, while the Dell OptiPlex 3040M has only 1 slots.

If you want the fastest transfer speeds for your SSD, M.2 interface is crucial. In case M.2 SSD slot is a mandatory requirement for you, go with the Dell OptiPlex 5040 MT. Sadly, the Dell OptiPlex 3040M has no such slot, and you will be forced to use the SATA interface.
Remark: Make sure that the M.2 slot supports the PCIe (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 6 Gb/s, while the PCIe 3.0 x4 will support speeds up to 32 Gb/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 3040M comes with a decent 65 Watt PSU, but the Dell OptiPlex 5040 MT has a more powerful one rated at 240 Watts. Choosing either one depends on your specific requirements and use case.