Dell OptiPlex 990 USFF vs. Dell Vostro 3681

Comparison and Differences

Dell_OptiPlex_990_USFF.jpg case front and back pannelDell_Vostro_3681.jpg case front and back pannel
Model
Form factorUltra SmallSmall
CPU optionsIntel Gen2 i3/i5/i7; Celeron; Pentium;Intel Gen10 i3/i5/i7; Celeron; Pentium;
ChipsetQ67B460
Dedicated GPU *N.A.GeForce GT 1030 Low Profile
RAMDIMM DDR3-1333DIMM DDR4-2666/2933
RAM slots22
RAM speed1333 MT/s2933 MT/s
RAM max8 GB64 GB
USB ports(7x)USB-A 2.0; (4x) USB-A 3.0; (4x) USB-A 2.0;
Video portsDisplayPort 1.2; VGA;HDMI 1.4b; VGA;
Other portsRJ45; Hdph; (2x) Mic; Line-Out; Line-In; PS2/COM; Serial; Parallel;RJ45; Headset; Mic; Line-Out; Line-In; Card Reader;
Optional portsN.A.N.A.
SATA ports22
PCI slotsN.A.PCIe 3.0 x16; PCIe 3.0 x1;
M.2 slotsN.A.M.2 2280/2230 M-key (PCIe 3.0 x4, NVMe); M.2 2230 (WiFi/BT);
Drive bays2.5in; 5.25in(slim);3.5in; 9.5mm
PSU200 W200 W
Weight3.27 kg (7.20 lb)4.66 Kg (10.28 lbs)
Released20112020
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 990 USFF and Dell Vostro 3681

If you are looking for a more modern desktop, then you should go with the Dell Vostro 3681 which was released in 2020. The Dell OptiPlex 990 USFF is older and entered production in 2011.

If you are looking for the smaller form factor the Dell OptiPlex 990 USFF is the right one for you. It is smaller than the Dell Vostro 3681 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 3681 as it is running a newer generation CPU. This is not to say that Dell OptiPlex 990 USFF 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 Vostro 3681 is using the faster 2933 MT/s RAM. The Dell OptiPlex 990 USFF 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 Vostro 3681 as it has the ability to run 64 GB of RAM. The Dell OptiPlex 990 USFF 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 Vostro 3681 has 8 USB ports. The Dell OptiPlex 990 USFF is inferior in this regard and packs 7 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 990 USFF has a DisplayPort. The Dell Vostro 3681 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 3681 comes with an HDMI port, while the Dell OptiPlex 990 USFF 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 slots are located on the motherboard and it is where SSD, HDD and Optical Disk Drives are connected. Each of the two models being compared have 2 SATA slot(s). Keep in mind that having too few SATA slots might limit your options for connecting additional memory drives.

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 Vostro 3681. Sadly, the Dell OptiPlex 990 USFF 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 200 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_990_USFF_motherboard.jpg motherboard layoutDell_Vostro_3681_motherboard.jpg motherboard layout