Dell OptiPlex 7040 SFF vs. Dell OptiPlex 790 SFF

Comparison and Differences

Dell_OptiPlex_7040_SFF.jpg case front and back pannelDell_OptiPlex_790_SFF.jpg case front and back pannel
Model
Form factorSmallSmall
CPU optionsIntel Gen6 i3/i5/i7Intel Gen2 i3/i5/i7; Celeron; Pentium;
ChipsetQ170Q65
Dedicated GPU *GeForce GT 1030 Low ProfileGeForce 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 ports33
PCI slotsPCIe 3.0 x16; PCIe 3.0 x4;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/(2x)2.5in; 5.25in (slim); 3.5in; 2.5in; 5.25in(slim);
PSU180 W240 W
Weight6.00 kg (13.22 lb)5.70 kg (12.57 lb)
Released20152011
Manuallinklink
Price**Check PriceCheck Price

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* 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 SFF and Dell OptiPlex 790 SFF

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

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 7040 SFF 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 SFF 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 SFF 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 SFF 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 SFF is the better choice.

The Dell OptiPlex 7040 SFF 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 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.

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 SFF. 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

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 7040 SFF comes with a decent 180 Watt PSU, but the Dell OptiPlex 790 SFF has a more powerful one rated at 240 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

Dell_OptiPlex_7040_SFF_motherboard.jpg motherboard layoutDell_OptiPlex_790_SFF_motherboard.jpg motherboard layout