Acer Veriton X4670g vs. Alienware X51
Comparison and Differences
Differences between Acer Veriton X4670g and Alienware X51
Both models have the same form factor, meaning reoughtly they have the same phiysical size and form.
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 Acer Veriton X4670g 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.
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 Acer Veriton X4670g is using the faster 2933 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 Acer Veriton X4670g as it has the ability to run 64 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.
In total the Acer Veriton X4670g has 9 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 Acer Veriton X4670g, is that it has 5 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 Acer Veriton X4670g 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 Alienware X51 comes with an HDMI port, while the Acer Veriton X4670g does not support the interface. Of course missing HDMI port is something that can be easily fixed with a good adapter (e.g. DisplayPort to HDMI).
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 X51 is better equipped as it comes with 4 SATA slot(s), while the Acer Veriton X4670g has 3 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 Acer Veriton X4670g. 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!
Having a Power Supply Unit with high power rating is important, if you are going to use components which require extra power. The Acer Veriton X4670g comes with a decent 300 Watt PSU, but the Alienware X51 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.