Dell OptiPlex 390 SFF vs. Dell OptiPlex 7040 MT

Comparison and Differences

Dell_OptiPlex_390_SFF.jpg case front and back pannelDell_OptiPlex_7040_MT.jpg case front and back pannel
Model
Form factorSmallMini Tower
CPU optionsIntel Gen2 i3/i5/i7; Celeron; Pentium;Intel Gen6 i3/i5/i7
ChipsetH61Q170
Dedicated GPU *GeForce GTX 1650 Low ProfileGeForce GTX 1650 Super
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 ports24
PCI slotsPCIe 2.0 x16; PCIe 2.0 x1;PCIe 3.0 x16; PCIe 3.0 x16 (wired x4); PCIe 3.0 x1; PCI;
M.2 slotsN.A.M.2 2280 M-key (PCIe 3.0 x4, NVMe)
Drive bays3.5in; 5.25in(slim);3.5in/5.25in; (2x) 2.5in; 5.25in (slim);
PSU240 W240 W
Weight5.70 kg (12.57 lb)8.00 kg (17.64 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 MT

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 390 SFF is older and entered production in 2011.

If you are looking for the smaller form factor the Dell OptiPlex 390 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 390 SFF is bad - it can still run some powerful CPUs, albeit being an older generation.

Memory

The Dell OptiPlex 7040 MT 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 MT 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 MT 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 MT 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 MT 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 MT is better equipped as it comes with 4 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 MT. 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

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_390_SFF_motherboard.jpg motherboard layoutDell_OptiPlex_7040_MT_motherboard.jpg motherboard layout