Dell OptiPlex 390 SFF vs. Dell OptiPlex 7040 SFF

Comparison and Differences

Dell_OptiPlex_390_SFF.jpg case front and back pannelDell_OptiPlex_7040_SFF.jpg case front and back pannel
Model
Form factorSmallSmall
CPU optionsIntel Gen2 i3/i5/i7; Celeron; Pentium;Intel Gen6 i3/i5/i7
ChipsetH61Q170
Dedicated GPU *GeForce GTX 1650 Low ProfileGeForce GT 1030 Low Profile
RAMDIMM DDR3-1333DIMM DDR4-2133
RAM slots24
RAM speed1333 MT/s2133 MT/s
RAM max8 GB64 GB
USB ports(8x)USB-A 2.0; (6x) USB-A 3.0; (4x) USB-A 2.0;
Video portsHDMI 1.2; VGA;(2x) Display Port 1.2; HDMI 1.4;
Other portsRJ45; Hdph; Line-Out; Line-In and Mic; Mic; PS2/COM;Serial; (2x) PS2; RJ45; Headset; Line-Out;
Optional portsN.A.VGA; Media Card Reader;
SATA ports23
PCI slotsPCIe 2.0 x16; PCIe 2.0 x1;PCIe 3.0 x16; PCIe 3.0 x4;
M.2 slotsN.A.M.2 2280 M-key (PCIe 3.0 x4, NVMe)
Drive bays3.5in; 5.25in(slim);3.5in/(2x)2.5in; 5.25in (slim);
PSU240 W180 W
Weight5.70 kg (12.57 lb)6.00 kg (13.22 lb)
Released20112015
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 390 SFF and Dell OptiPlex 7040 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 390 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 390 SFF is bad - it can still run some powerful CPUs, albeit being an older generation.

Memory

The Dell OptiPlex 7040 SFF has 4 RAM slots while the Dell OptiPlex 390 SFF has only 2 slot(s). This is not something to worry about. Just make sure you take it into consideration when planning how much RAM you are going to use.

The Dell OptiPlex 7040 SFF is using the faster 2133 MT/s RAM. The Dell OptiPlex 390 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 390 SFF can do a bit less at max 8 GB. Most of the times, this should be sufficient for the majority of users.

Ports

In total the Dell OptiPlex 7040 SFF has 10 USB ports. The Dell OptiPlex 390 SFF is inferior in this regard and packs 8 USB ports. In any case, if you miss USB ports, you can always purchase a USB hub. 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.

Unfortunately, only the Dell OptiPlex 7040 SFF has a DisplayPort. The Dell OptiPlex 390 SFF does not have one? Don't worry though, nowadays video adapters are cheap and you can get almost any combination of conversion types.

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

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 SFF is better equipped as it comes with 3 SATA slot(s), while the Dell OptiPlex 390 SFF has 2 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 SFF. Sadly, the Dell OptiPlex 390 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 390 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_390_SFF_motherboard.jpg motherboard layoutDell_OptiPlex_7040_SFF_motherboard.jpg motherboard layout