Dell OptiPlex 7040 MT vs. Dell OptiPlex 790 SFF

Comparison and Differences

Dell_OptiPlex_7040_MT.jpg case front and back pannelDell_OptiPlex_790_SFF.jpg case front and back pannel
Model
Form factorMini TowerSmall
CPU optionsIntel Gen6 i3/i5/i7Intel Gen2 i3/i5/i7; Celeron; Pentium;
ChipsetQ170Q65
Dedicated GPU *GeForce GTX 1650 SuperGeForce GTX 1650 Low Profile
RAMDIMM DDR4-2133 DIMM DDR3-1333
RAM slots44
RAM speed2133 MT/s1333 MT/s
RAM max64 GB16 GB
USB ports(6x) USB-A 3.0; (4x) USB-A 2.0; (10x)USB-A 2.0;
Video ports(2x) Display Port 1.2; HDMI 1.4;DisplayPort 1.2; VGA;
Other portsSerial; (2x) PS2; RJ45; Headset; Line-Out; RJ45; Hdph; (2x) Mic; Line-Out; Line-In; PS2/COM; Serial; Parallel;
Optional portsVGA; Media Card Reader;N.A.
SATA ports43
PCI slotsPCIe 3.0 x16; PCIe 3.0 x16 (wired x4); PCIe 3.0 x1; PCI; PCIe 2.0 x16; PCIe 2.0 x4; PCIe 2.0 x1;
M.2 slotsM.2 2280 M-key (PCIe 3.0 x4, NVMe) N.A.
Drive bays3.5in/5.25in; (2x) 2.5in; 5.25in (slim);3.5in; 2.5in; 5.25in(slim);
PSU240 W240 W
Weight8.00 kg (17.64 lb)5.70 kg (12.57 lb)
Released20152011
Manuallinklink
Price**Check PriceCheck Price

** As an Amazon associate we earn from qualifying purchases.
* Dedicated GPU warning: Check if your particular power supply model has enough power. Additionally some PSUs don't come with an auxiliary PCIe power connector and you may need to buy a SATA to PCIe power adapter.

Differences between Dell OptiPlex 7040 MT and Dell OptiPlex 790 SFF

If you are looking for a more modern desktop, then you should go with the Dell OptiPlex 7040 MT which was released in 2015. The Dell OptiPlex 790 SFF is older and entered production in 2011.

If you are looking for the smaller form factor the Dell OptiPlex 790 SFF is the right one for you. It is smaller than the Dell OptiPlex 7040 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 7040 MT as it is running a newer generation CPU. This is not to say that Dell OptiPlex 790 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 7040 MT is using the faster 2133 MT/s RAM. The Dell OptiPlex 790 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 Dell OptiPlex 7040 MT as it has the ability to run 64 GB of RAM. The Dell OptiPlex 790 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 Dell OptiPlex 7040 MT comes with 2 ports, while the Dell OptiPlex 790 SFF has only 1. If you are planning to use multiple monitors, the Dell OptiPlex 7040 MT is the better choice.

The Dell OptiPlex 7040 MT comes with an HDMI port, while the Dell OptiPlex 790 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 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 7040 MT is better equipped as it comes with 4 SATA slot(s), while the Dell OptiPlex 790 SFF has 3 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 Dell OptiPlex 7040 MT. Sadly, the Dell OptiPlex 790 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

Looking at the Power Supply Unit (PSU) of the two models we don't see any differences. For either of them you get a maximum power of 240 Watts. However be careful, many models have more than one power supply option. When buying your computer, it is a good idea to get a version with the most powerful PSU. This will potentially allow you to upgrade to a more powerful GPU for example.

Motherboard

Dell_OptiPlex_7040_MT_motherboard.jpg motherboard layoutDell_OptiPlex_790_SFF_motherboard.jpg motherboard layout