Dell OptiPlex 390 DT vs. Dell Vostro 3668

Differences between Dell OptiPlex 390 DT and Dell Vostro 3668

If you are looking for a more modern desktop, then you should go with the Dell Vostro 3668 which was released in 2016. The Dell OptiPlex 390 DT is older and entered production in 2011.

If you are looking for the smaller form factor the Dell Vostro 3668 is the right one for you. It is smaller than the Dell OptiPlex 390 DT 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 3668 as it is running a newer generation CPU. This is not to say that Dell OptiPlex 390 DT 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 3668 is using the faster 2400 MT/s RAM. The Dell OptiPlex 390 DT 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 3668 as it has the ability to run 16 GB of RAM. The Dell OptiPlex 390 DT 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 390 DT has 8 USB ports. The Dell Vostro 3668 is inferior in this regard and packs 6 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.

Nowadays, almost every new computer comes equipped with a DisplayPort. However, none of the devices being compared here has one. Don't worry though, DisplayPort adapters are very cheap and you can get virtually 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 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 4 SATA slot(s). Keep in mind that having too few SATA slots might limit your options for connecting additional memory drives.

M.2 SSD interface allows you to transfer data with higher speeds compared to the old SATA interface. Unfortunately, neither the Dell OptiPlex 390 DT, nor the Dell Vostro 3668 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 Vostro 3668 comes with a decent 240 Watt PSU, but the Dell OptiPlex 390 DT has a more powerful one rated at 250 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