Alienware X51 vs. Dell OptiPlex 5090 MT
Comparison and Differences
Differences between Alienware X51 and Dell OptiPlex 5090 MT
If you are looking for a more modern desktop, then you should go with the Dell OptiPlex 5090 MT which was released in 2021. The Alienware X51 is older and entered production in 2011.
If you are looking for the smaller form factor the Alienware X51 is the right one for you. It is smaller than the Dell OptiPlex 5090 MT 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 5090 MT as it is running a newer generation CPU. This is not to say that Alienware X51 is bad - it can still run some powerful CPUs, albeit being an older generation.
Memory
The Dell OptiPlex 5090 MT has 4 RAM slots while the Alienware X51 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 Dell OptiPlex 5090 MT is using the faster 3200 MT/s RAM. The Alienware X51 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 Dell OptiPlex 5090 MT as it has the ability to run 128 GB of RAM. The Alienware X51 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 Dell OptiPlex 5090 MT has 10 USB ports. The Alienware X51 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. What is nice about the Dell OptiPlex 5090 MT, is that it has 3 USB 3.1 port(s) which allows transfer of up to 10Gb/s. Unfortunately, the Alienware X51 has no such port, thus restricting your transfer speeds significantly. For people who want to use external drives on regular basis, this might be an issue.
Unfortunately, only the Dell OptiPlex 5090 MT has a DisplayPort. The Alienware X51 does not have one? Don't worry though, nowadays video adapters are cheap and you can get almost any combination of conversion types.
The HDMI video interface is broadly used and the majority of the external displays support it. Thus, it is nice to see that both models have this video interface. If you are going to use multiple monitors go with the Dell OptiPlex 5090 MT which has 2 ports. The Alienware X51 has only 1 ports.
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 4 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 5090 MT. Sadly, the Alienware X51 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 Alienware X51 comes with a decent 330 Watt PSU, but the Dell OptiPlex 5090 MT has a more powerful one rated at 360 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
