Acer Veriton X2640g vs. Fujitsu Esprimo Q556
Comparison and Differences
Differences between Acer Veriton X2640g and Fujitsu Esprimo Q556
Both computers, the Acer Veriton X2640g and the Fujitsu Esprimo Q556, were released during the same year - 2015.
If you are looking for the smaller form factor the Fujitsu Esprimo Q556 is the right one for you. It is smaller than the Acer Veriton X2640g 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 Acer Veriton X2640g as it is running a newer generation CPU. This is not to say that Fujitsu Esprimo Q556 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.
None of the desktops has an advantage when it comes to the speed of the RAM being used. Both models support RAM speeds of up to 2133. In addition, you will be able to install the same amount of RAM in both models, and most probably 32 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.
Ports
In total the Acer Veriton X2640g has 8 USB ports. The Fujitsu Esprimo Q556 is inferior in this regard and packs 6 USB ports. In any case, if you miss USB ports, you can always purchase a USB hub. 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.
Unfortunately, only the Fujitsu Esprimo Q556 has a DisplayPort. The Acer Veriton X2640g 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 Fujitsu Esprimo Q556 is better equipped as it comes with 2 SATA slot(s), while the Acer Veriton X2640g has 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 Fujitsu Esprimo Q556. Sadly, the Acer Veriton X2640g 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 Fujitsu Esprimo Q556 comes with a decent 65 Watt PSU, but the Acer Veriton X2640g has a more powerful one rated at 220 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.