Dell OptiPlex 7090 SFF vs. Dell Vostro 3900

Comparison and Differences

Dell_OptiPlex_7090_SFF.jpg case front and back pannelDell_Vostro_3900.jpg case front and back pannel
Model
Form factorSmallMini Tower
CPU optionsIntel Gen10&11 i3/i5/i7/i9;Intel Gen4 i3/i5/i7; Pentium; Celeron;
ChipsetQ570H81
Dedicated GPU *AMD Radeon RX 6400 Low ProfileGeForce GTX 1660 Super
RAMDIMM DDR4-2666/2933/3200DIMM DDR3-1600
RAM slots42
RAM speed3200 MT/s1600 MT/s
RAM max128 GB16 GB
USB portsUSB 3.2 Type C; USB 3.1 Type C; (2x) USB-A 3.1; USB-A 3.0; (x4) USB-A 2.0;(6x)USB-A 2.0; (2x)USB-A 3.0;
Video ports(3x) Display Port 1.4; HDMI 2.0b;HDMI 1.2; VGA;
Other portsRJ45; Audio; Line-Out/In; Serial; (x2) PS2RJ45; Hdph; (2x) Mic; Line-Out; Line-In; PS2
Optional portsUSB Type-C (DP Alt Mode); Media Card Reader;N/A
SATA ports34
PCI slotsPCIe 4.0 x16; PCIe 3.0 x4;PCIe 2.0 x16; (2x) PCIe 2.0 x1; PCI
M.2 slotsM.2 2280/2230 M-key (PCIe 3.0 x4, NVMe); M.2 2230 M-key (PCIe); M.2 2230 (WiFi/BT) N.A.
Drive bays(x2) 3.5in; (2x) 2.5in; 5.25in (slim);3.5in; 5.25in;
PSU200/300 W300 W
Weight5.72 kg (12.61 lb)8.50 kg (18.73 lbs)
Released20212014
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 7090 SFF and Dell Vostro 3900

If you are looking for a more modern desktop, then you should go with the Dell OptiPlex 7090 SFF which was released in 2021. The Dell Vostro 3900 is older and entered production in 2014.

If you are looking for the smaller form factor the Dell OptiPlex 7090 SFF is the right one for you. It is smaller than the Dell Vostro 3900 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 7090 SFF as it is running a newer generation CPU. This is not to say that Dell Vostro 3900 is bad - it can still run some powerful CPUs, albeit being an older generation.

Memory

The Dell OptiPlex 7090 SFF has 4 RAM slots while the Dell Vostro 3900 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 7090 SFF is using the faster 3200 MT/s RAM. The Dell Vostro 3900 is slower by supporting RAM speeds of up to 1600 MT/s. Additionally, if you will be needing a lot of RAM, better go for the Dell OptiPlex 7090 SFF as it has the ability to run 128 GB of RAM. The Dell Vostro 3900 can do a bit less at max 16 GB. Most of the times, this should be sufficient for the majority of users.

Ports

In total the Dell OptiPlex 7090 SFF has 9 USB ports. The Dell Vostro 3900 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. What is nice about the Dell OptiPlex 7090 SFF, is that it has 3 USB 3.1 port(s) which allows transfer of up to 10Gb/s. Unfortunately, the Dell Vostro 3900 has no such port, thus restricting your transfer speeds significantly. For people who want to use external drives on regular basis, this might be an issue.

Unfortunately, only the Dell OptiPlex 7090 SFF has a DisplayPort. The Dell Vostro 3900 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 Vostro 3900 is better equipped as it comes with 4 SATA slot(s), while the Dell OptiPlex 7090 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 7090 SFF. Sadly, the Dell Vostro 3900 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 300 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_7090_SFF_motherboard.jpg motherboard layoutDell_Vostro_3900_motherboard.jpg motherboard layout