Dell OptiPlex 790 SFF vs. Dell Vostro 3902

Comparison and Differences

Dell_OptiPlex_790_SFF.jpg case front and back pannelDell_Vostro_3902.jpg case front and back pannel
Model
Form factorSmallMini Tower
CPU optionsIntel Gen2 i3/i5/i7; Celeron; Pentium;Intel Gen4 i3/i5/i7; Pentium; Celeron;
ChipsetQ65H81
Dedicated GPU *GeForce GTX 1650 Low ProfileGeForce GTX 1660 Super
RAMDIMM DDR3-1333DIMM DDR3-1600
RAM slots42
RAM speed1333 MT/s1600 MT/s
RAM max16 GB16 GB
USB ports(10x)USB-A 2.0; (6x)USB-A 2.0; (2x)USB-A 3.0;
Video portsDisplayPort 1.2; VGA;HDMI 1.2; VGA;
Other portsRJ45; Hdph; (2x) Mic; Line-Out; Line-In; PS2/COM; Serial; Parallel;RJ45; Hdph; (2x) Mic; Line-Out; Line-In; PS2
Optional portsN.A.N/A
SATA ports34
PCI slotsPCIe 2.0 x16; PCIe 2.0 x4; PCIe 2.0 x1;PCIe 2.0 x16; (2x) PCIe 2.0 x1; PCI
M.2 slotsN.A.N.A.
Drive bays3.5in; 2.5in; 5.25in(slim);3.5in; 5.25in;
PSU240 W300 W
Weight5.70 kg (12.57 lb)8.50 kg (18.73 lbs)
Released20112014
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 790 SFF and Dell Vostro 3902

If you are looking for a more modern desktop, then you should go with the Dell Vostro 3902 which was released in 2014. 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 Vostro 3902 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 Vostro 3902 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

The Dell OptiPlex 790 SFF has 4 RAM slots while the Dell Vostro 3902 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 Vostro 3902 is using the faster 1600 MT/s RAM. The Dell OptiPlex 790 SFF is slower by supporting RAM speeds of up to 1333 MT/s. In addition, 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.

Ports

In total the Dell OptiPlex 790 SFF has 10 USB ports. The Dell Vostro 3902 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 790 SFF has a DisplayPort. The Dell Vostro 3902 does not have one? Don't worry though, nowadays video adapters are cheap and you can get almost any combination of conversion types.

The Dell Vostro 3902 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 Vostro 3902 is better equipped as it comes with 4 SATA slot(s), while the Dell OptiPlex 790 SFF has 3 slot(s).

M.2 SSD interface allows you to transfer data with higher speeds compared to the old SATA interface. Unfortunately, neither the Dell OptiPlex 790 SFF, nor the Dell Vostro 3902 has one. However, you can still use a SATA SSD drive which should give you satisfactory performance.

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 790 SFF comes with a decent 240 Watt PSU, but the Dell Vostro 3902 has a more powerful one rated at 300 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_790_SFF_motherboard.jpg motherboard layoutDell_Vostro_3902_motherboard.jpg motherboard layout