Dell OptiPlex 790 USFF vs. HP ProDesk 400 G6 SFF

Comparison and Differences

Dell_OptiPlex_790_USFF.jpg case front and back pannelHP_ProDesk_400_G6_SFF.jpg case front and back pannel
Model
Form factorUltra SmallSmall
CPU optionsIntel Gen2 i3/i5/i7; Celeron; Pentium;Intel Gen8&9 i3/i5/i7; Celeron; Pentium;
ChipsetQ65B360
Dedicated GPU *N.A.GeForce GT 1030 Low Profile
RAMDIMM DDR3-1333DIMM DDR4-2666
RAM slots22
RAM speed1333 MT/s2666 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;DisplayPort; VGA;
Other portsRJ45; Hdph; (2x) Mic; Line-Out; Line-In; PS2/COM; Serial; Parallel;RJ45; Headset; Line-In; Line-Out;
Optional portsN.A.SD card reader; Serial; Serial and (2x) PS2; DP/HDMI/VGA/USB-C;
SATA ports22
PCI slotsN.A.PCIe 3.0 x16; PCIe 3.0 x1 ;
M.2 slotsN.A.M.2 2280/2230 M-key (PCIe x4); M.2 2230 (WiFi/BT)
Drive bays2.5in; 5.25in(slim);(2x) 2.5/3.5in; 5.25in (slim);
PSU200 W180 W
Weight3.27 kg (7.20 lb)4.6 kg (10.14 lb)
Released20112019
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 790 USFF and HP ProDesk 400 G6 SFF

If you are looking for a more modern desktop, then you should go with the HP ProDesk 400 G6 SFF which was released in 2019. The Dell OptiPlex 790 USFF is older and entered production in 2011.

If you are looking for the smaller form factor the Dell OptiPlex 790 USFF is the right one for you. It is smaller than the HP ProDesk 400 G6 SFF 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 G6 SFF as it is running a newer generation CPU. This is not to say that Dell OptiPlex 790 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 HP ProDesk 400 G6 SFF is using the faster 2666 MT/s RAM. The Dell OptiPlex 790 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 HP ProDesk 400 G6 SFF as it has the ability to run 64 GB of RAM. The Dell OptiPlex 790 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 HP ProDesk 400 G6 SFF has 8 USB ports. The Dell OptiPlex 790 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.

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 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 HP ProDesk 400 G6 SFF. Sadly, the Dell OptiPlex 790 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

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 G6 SFF comes with a decent 180 Watt PSU, but the Dell OptiPlex 790 USFF has a more powerful one rated at 200 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_790_USFF_motherboard.jpg motherboard layoutHP_ProDesk_400_G6_SFF_motherboard.jpg motherboard layout