Dell OptiPlex 990 DT vs. HP ProDesk 400 G2 SFF

Comparison and Differences

Dell_OptiPlex_990_DT.jpg case front and back pannelHP_ProDesk_400_G2_SFF.jpg case front and back pannel
Model
Form factorDesktopSmall
CPU optionsIntel Gen2 i3/i5/i7; Celeron; Pentium;Intel Gen4 i3/i5/i7; Celeron; Pentium;
ChipsetQ67H81
Dedicated GPU *GeForce GTX 1650 Low ProfileGeForce GTX 1650 Low Profile
RAMDIMM DDR3-1333DIMM DDR3-1600
RAM slots42
RAM speed1333 MT/s1600 MT/s
RAM max16 GB16 GB
USB ports(10x)USB-A 2.0; (2x)USB-A 3.0; (6x)USB-A 2.0;
Video portsDisplayPort 1.2; VGA;DisplayPort; VGA;
Other portsRJ45; Hdph; (2x) Mic; Line-Out; Line-In; PS2/COM; Serial; Parallel;RJ45; Hdph; Mic; Line-Out; Line-In; Serial; (2x) PS2;
Optional portsN.A.Media card reader; Serial; Parallel;
SATA ports33
PCI slotsPCIe 2.0 x16; PCIe 2.0 x4; PCIe 2.0 x1;PCIe x16; (3x) PCIe x1;
M.2 slotsN.A.N.A.
Drive bays3.5in; 2.5in; 5.25in;2.5in; (2x) 3.5in; 5.25in (slim)
PSU250 W240 W
Weight7.56 kg (16.67 lb)5.9 kg (13.0 lb)
Released20112014
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 990 DT and HP ProDesk 400 G2 SFF

If you are looking for a more modern desktop, then you should go with the HP ProDesk 400 G2 SFF which was released in 2014. The Dell OptiPlex 990 DT is older and entered production in 2011.

If you are looking for the smaller form factor the HP ProDesk 400 G2 SFF is the right one for you. It is smaller than the Dell OptiPlex 990 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 HP ProDesk 400 G2 SFF as it is running a newer generation CPU. This is not to say that Dell OptiPlex 990 DT is bad - it can still run some powerful CPUs, albeit being an older generation.

Memory

The Dell OptiPlex 990 DT has 4 RAM slots while the HP ProDesk 400 G2 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 HP ProDesk 400 G2 SFF is using the faster 1600 MT/s RAM. The Dell OptiPlex 990 DT is slower by supporting RAM speeds of up to 1333 MT/s. In addition, you will be able to install the same amount of RAM in both models, and most probably 16 GB of RAM will be enough for most people. However, if you will be needing more RAM, make sure to check other desktop models too.

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.

The DisplayPort is usually the more popular video port used with desktops and laptops, while the HDMI is used predominantly in consumer electronics. That's why, it is good to see that both of the models come with a DisplayPort.

None of the models has an HDMI port. If your monitor supports only the HDMI interface, you will need to buy an adapter. Such adapters are cheap so nothing to worry about.

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 3 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 990 DT, nor the HP ProDesk 400 G2 SFF 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 HP ProDesk 400 G2 SFF comes with a decent 240 Watt PSU, but the Dell OptiPlex 990 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

Dell_OptiPlex_990_DT_motherboard.jpg motherboard layoutHP_ProDesk_400_G2_SFF_motherboard.jpg motherboard layout