Alienware Aurora R9 vs. Dell OptiPlex 990 USFF
Comparison and Differences
Differences between Alienware Aurora R9 and Dell OptiPlex 990 USFF
If you are looking for a more modern desktop, then you should go with the Alienware Aurora R9 which was released in 2018. The Dell OptiPlex 990 USFF is older and entered production in 2011.
If you are looking for the smaller form factor the Dell OptiPlex 990 USFF is the right one for you. It is smaller than the Alienware Aurora R9 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 Alienware Aurora R9 as it is running a newer generation CPU. This is not to say that Dell OptiPlex 990 USFF is bad - it can still run some powerful CPUs, albeit being an older generation.
Memory
The Alienware Aurora R9 has 4 RAM slots while the Dell OptiPlex 990 USFF 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 Aurora R9 is using the faster 3000 MT/s RAM. The Dell OptiPlex 990 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 Alienware Aurora R9 as it has the ability to run 64 GB of RAM. The Dell OptiPlex 990 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 Alienware Aurora R9 has 14 USB ports. The Dell OptiPlex 990 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. What is nice about the Alienware Aurora R9, is that it has 2 USB 3.1 port(s) which allows transfer of up to 10Gb/s. Unfortunately, the Dell OptiPlex 990 USFF 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.
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 ports are placed on the system board and it is where you connect your HDD, SSD and Optical Disk Drives. More SATA slots will allow you to have more drives running at the same time. In this regard the Alienware Aurora R9 is better equipped as it comes with 4 SATA slot(s), while the Dell OptiPlex 990 USFF has 2 slot(s).
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 Alienware Aurora R9. Sadly, the Dell OptiPlex 990 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 Dell OptiPlex 990 USFF comes with a decent 200 Watt PSU, but the Alienware Aurora R9 has a more powerful one rated at 850 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
