Alienware X51 R2 vs. Dell OptiPlex 790 SFF

Comparison and Differences

Alienware_X51_R2.jpg case front and back pannelDell_OptiPlex_790_SFF.jpg case front and back pannel
Model
Form factorSmall GamingSmall
CPU optionsIntel Gen4 i3/i5/i7;Intel Gen2 i3/i5/i7; Celeron; Pentium;
ChipsetH87Q65
Dedicated GPU *GeForce GTX 1650 SuperGeForce GTX 1650 Low Profile
RAMDIMM DDR3-1600 DIMM DDR3-1333
RAM slots24
RAM speed1600 MT/s1333 MT/s
RAM max16 GB16 GB
USB ports(6x) USB 3.0 Type A; (2x) USB-A 2.0; (10x)USB-A 2.0;
Video portsHDMI 1.4b;DisplayPort 1.2; VGA;
Other portsRJ45; Headset; Line-Out; Line-In; S/PDFI optical/analog;RJ45; Hdph; (2x) Mic; Line-Out; Line-In; PS2/COM; Serial; Parallel;
Optional portsN.A.N.A.
SATA ports33
PCI slotsPCIe 3.0 x16;PCIe 2.0 x16; PCIe 2.0 x4; PCIe 2.0 x1;
M.2 slotsN.A.N.A.
Drive bays(2x) 2.5in; 3.25in; 5.25in;3.5in; 2.5in; 5.25in(slim);
PSU240/330 W240 W
Weight5.49 kgs (12.10 lbs)5.70 kg (12.57 lb)
Released20132011
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 Alienware X51 R2 and Dell OptiPlex 790 SFF

If you are looking for a more modern desktop, then you should go with the Alienware X51 R2 which was released in 2013. The Dell OptiPlex 790 SFF is older and entered production in 2011.

Both models have the same form factor, meaning reoughtly they have the same phiysical size and form.

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 Alienware X51 R2 as it is running a newer generation CPU. This is not to say that Dell OptiPlex 790 SFF is bad - it can still run some powerful CPUs, albeit being an older generation.

Memory

The Dell OptiPlex 790 SFF has 4 RAM slots while the Alienware X51 R2 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 Alienware X51 R2 is using the faster 1600 MT/s RAM. The Dell OptiPlex 790 SFF 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

In total the Dell OptiPlex 790 SFF has 10 USB ports. The Alienware X51 R2 is inferior in this regard and packs 8 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 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 790 SFF, nor the Alienware X51 R2 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 790 SFF comes with a decent 240 Watt PSU, but the Alienware X51 R2 has a more powerful one rated at 330 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

Alienware_X51_R2_motherboard.jpg motherboard layoutDell_OptiPlex_790_SFF_motherboard.jpg motherboard layout