Alienware X51 R2 vs. Dell OptiPlex 3090 Tower

Comparison and Differences

Alienware_X51_R2.jpg case front and back pannelDell_OptiPlex_3090_Tower.jpg case front and back pannel
Model
Form factorSmall GamingMini Tower
CPU optionsIntel Gen4 i3/i5/i7;Intel Gen 10 i3/i5/i7/i9; Pentium
ChipsetH87Q470
Dedicated GPU *GeForce GTX 1650 SuperGeForce GTX 1650
RAMDIMM DDR3-1600 DIMM DDR4-2666
RAM slots22
RAM speed1600 MT/s2666 MT/s
RAM max16 GB64 GB
USB ports(6x) USB 3.0 Type A; (2x) USB-A 2.0; (4x) USB-A 2.0; (4x) USB-A 3.0;
Video portsHDMI 1.4b;Display Port 1.4a; HDMI 1.4b;
Other portsRJ45; Headset; Line-Out; Line-In; S/PDFI optical/analog;RJ45; Audio; Line-Out/In;
Optional portsN.A.HDMI 2.0b/Displayport/VGA;
SATA ports33
PCI slotsPCIe 3.0 x16;PCIe 3.0 x16; (2x) PCIe 3.0 x1;
M.2 slotsN.A.M.2 2230/2280 (PCIe 4.0 x4, NVMe); M.2 2230 (WiFi/BT)
Drive bays(2x) 2.5in; 3.25in; 5.25in;3.5in; 2.5in; 5.25in (slim);
PSU240/330 W260 W
Weight5.49 kgs (12.10 lbs)6.50 kg (14.33 lb)
Released20132021
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 Alienware X51 R2 and Dell OptiPlex 3090 Tower

If you are looking for a more modern desktop, then you should go with the Dell OptiPlex 3090 Tower which was released in 2021. The Alienware X51 R2 is older and entered production in 2013.

If you are looking for the smaller form factor the Alienware X51 R2 is the right one for you. It is smaller than the Dell OptiPlex 3090 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 Dell OptiPlex 3090 Tower as it is running a newer generation CPU. This is not to say that Alienware X51 R2 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 OptiPlex 3090 Tower is using the faster 2666 MT/s RAM. The Alienware X51 R2 is slower by supporting RAM speeds of up to 1600 MT/s. Additionally, if you will be needing a lot of RAM, better go for the Dell OptiPlex 3090 Tower as it has the ability to run 64 GB of RAM. The Alienware X51 R2 can do a bit less at max 16 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.

DisplayPort is crucial for any desktop machine. It is good to see that both models are featuring DisplayPorts. However, the Dell OptiPlex 3090 Tower comes with 2 ports, while the Alienware X51 R2 has only 1. If you are planning to use multiple monitors, the Dell OptiPlex 3090 Tower is the better choice.

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.

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 Dell OptiPlex 3090 Tower. Sadly, the Alienware X51 R2 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 Dell OptiPlex 3090 Tower comes with a decent 260 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_3090_Tower_motherboard.jpg motherboard layout