Dell OptiPlex 390 SFF vs. Lenovo ThinkCentre M900 Tower

Comparison and Differences

Dell_OptiPlex_390_SFF.jpg case front and back pannelLenovo_ThinkCentre_M900_Tower.jpg case front and back pannel
Model
Form factorSmallMini Tower
CPU optionsIntel Gen2 i3/i5/i7; Celeron; Pentium;Intel Gen6 i3/i5/i7; Celeron; Pentium;
ChipsetH61Q170
Dedicated GPU *GeForce GTX 1650 Low ProfileGeForce GTX 1660 Super
RAMDIMM DDR3-1333DIMM DDR4-2133
RAM slots24
RAM speed1333 MT/s2133 MT/s
RAM max8 GB64 GB
USB ports(8x)USB-A 2.0; (8x)USB-A 3.0;
Video portsHDMI 1.2; VGA;(2x) DisplayPort 1.2; VGA;
Other portsRJ45; Hdph; Line-Out; Line-In and Mic; Mic; PS2/COM;RJ45; Hdph; (2x) Mic; Line-Out; Line-In; Serial;
Optional portsN.A.2x USB-A 2.0; Media card reader (USB 2.0); (2x) PS2; eSATA;
SATA ports23
PCI slotsPCIe 2.0 x16; PCIe 2.0 x1;PCIe 3.0 x16; PCIe 3.0 x1; PCIe 3.0 x16 (wired x4); M2 to PCI adapter (optional);
M.2 slotsN.A.M.2 (WiFi/BT or PCI extension card)
Drive bays3.5in; 5.25in(slim);(2x) 2.5/3.5in; (2x) 5.25in;
PSU240 WATX 250/400 W
Weight5.70 kg (12.57 lb)12.5 kg (27.5 lb)
Released20112015
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 390 SFF and Lenovo ThinkCentre M900 Tower

If you are looking for a more modern desktop, then you should go with the Lenovo ThinkCentre M900 Tower which was released in 2015. 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 Lenovo ThinkCentre M900 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 Lenovo ThinkCentre M900 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

The Lenovo ThinkCentre M900 Tower has 4 RAM slots while the Dell OptiPlex 390 SFF 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 Lenovo ThinkCentre M900 Tower is using the faster 2133 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 Lenovo ThinkCentre M900 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 Lenovo ThinkCentre M900 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 Lenovo ThinkCentre M900 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 Lenovo ThinkCentre M900 Tower is better equipped as it comes with 3 SATA slot(s), while the Dell OptiPlex 390 SFF has 2 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 390 SFF, nor the Lenovo ThinkCentre M900 Tower 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 390 SFF comes with a decent 240 Watt PSU, but the Lenovo ThinkCentre M900 Tower has a more powerful one rated at 400 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_390_SFF_motherboard.jpg motherboard layoutLenovo_ThinkCentre_M900_Tower_motherboard.jpg motherboard layout