Alienware Area 51 R4 vs. HP ProDesk 400 G4 SFF
Comparison and Differences
Differences between Alienware Area 51 R4 and HP ProDesk 400 G4 SFF
If you are looking for the smaller form factor the HP ProDesk 400 G4 SFF is the right one for you. It is smaller than the Alienware Area 51 R4 and will fit more easily under your desk.
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 Area 51 R4 as it is running a newer generation CPU. This is not to say that HP ProDesk 400 G4 SFF is bad - it can still run some powerful CPUs, albeit being an older generation.
The Alienware Area 51 R4 has 4 RAM slots while the HP ProDesk 400 G4 SFF 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 Area 51 R4 is using the faster 2933 MT/s RAM. The HP ProDesk 400 G4 SFF is slower by supporting RAM speeds of up to 2400 MT/s. In addition, you will be able to install the same amount of RAM in both models, and most probably 64 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.
In total the Alienware Area 51 R4 has 12 USB ports. The HP ProDesk 400 G4 SFF 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 Alienware Area 51 R4, is that it has 2 USB 3.1 port(s) which allows transfer of up to 10Gb/s. Unfortunately, the HP ProDesk 400 G4 SFF 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 HP ProDesk 400 G4 SFF has a DisplayPort. The Alienware Area 51 R4 does not have one? Don't worry though, nowadays video adapters are cheap and you can get almost any combination of conversion types.
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 Area 51 R4 is better equipped as it comes with 4 SATA slot(s), while the HP ProDesk 400 G4 SFF 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 Area 51 R4. Sadly, the HP ProDesk 400 G4 SFF 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!
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 G4 SFF comes with a decent 180 Watt PSU, but the Alienware Area 51 R4 has a more powerful one rated at 1500 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.