Dell OptiPlex 3090 Tower vs. Dell OptiPlex 390 SFF

Comparison and Differences

Dell_OptiPlex_3090_Tower.jpg case front and back pannelDell_OptiPlex_390_SFF.jpg case front and back pannel
Model
Form factorMini TowerSmall
CPU optionsIntel Gen 10 i3/i5/i7/i9; PentiumIntel Gen2 i3/i5/i7; Celeron; Pentium;
ChipsetQ470H61
Dedicated GPU *GeForce GTX 1650GeForce GTX 1650 Low Profile
RAMDIMM DDR4-2666DIMM DDR3-1333
RAM slots22
RAM speed2666 MT/s1333 MT/s
RAM max64 GB8 GB
USB ports(4x) USB-A 2.0; (4x) USB-A 3.0;(8x)USB-A 2.0;
Video portsDisplay Port 1.4a; HDMI 1.4b;HDMI 1.2; VGA;
Other portsRJ45; Audio; Line-Out/In;RJ45; Hdph; Line-Out; Line-In and Mic; Mic; PS2/COM;
Optional portsHDMI 2.0b/Displayport/VGA;N.A.
SATA ports32
PCI slotsPCIe 3.0 x16; (2x) PCIe 3.0 x1;PCIe 2.0 x16; PCIe 2.0 x1;
M.2 slotsM.2 2230/2280 (PCIe 4.0 x4, NVMe); M.2 2230 (WiFi/BT) N.A.
Drive bays3.5in; 2.5in; 5.25in (slim);3.5in; 5.25in(slim);
PSU260 W240 W
Weight6.50 kg (14.33 lb)5.70 kg (12.57 lb)
Released20212011
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 3090 Tower and Dell OptiPlex 390 SFF

If you are looking for a more modern desktop, then you should go with the Dell OptiPlex 3090 Tower which was released in 2021. 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 3090 Tower 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 3090 Tower 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

Both models have have equal amount of ram slots (2 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 3090 Tower is using the faster 2666 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 3090 Tower 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

Both models have the same amount of USB ports for total count of 8. 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.

Unfortunately, only the Dell OptiPlex 3090 Tower 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.

The Dell OptiPlex 390 SFF comes with an HDMI port, while the Dell OptiPlex 3090 Tower 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 OptiPlex 3090 Tower 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 3090 Tower. 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 390 SFF comes with a decent 240 Watt PSU, but the Dell OptiPlex 3090 Tower has a more powerful one rated at 260 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_3090_Tower_motherboard.jpg motherboard layoutDell_OptiPlex_390_SFF_motherboard.jpg motherboard layout