Dell OptiPlex 3070 SFF vs. Fujitsu Esprimo E520
Comparison and Differences
Differences between Dell OptiPlex 3070 SFF and Fujitsu Esprimo E520
If you are looking for a more modern desktop, then you should go with the Dell OptiPlex 3070 SFF which was released in 2019. The Fujitsu Esprimo E520 is older and entered production in 2014.
Both models have the same form factor, meaning reoughtly they have the same phiysical size and form.
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 3070 SFF as it is running a newer generation CPU. This is not to say that Fujitsu Esprimo E520 is bad - it can still run some powerful CPUs, albeit being an older generation.
Memory
The Fujitsu Esprimo E520 has 4 RAM slots while the Dell OptiPlex 3070 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 Dell OptiPlex 3070 SFF is using the faster 2666 MT/s RAM. The Fujitsu Esprimo E520 is slower by supporting RAM speeds of up to 1600 MT/s. 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
Both models have the same amount of USB ports for total count of 8. If this is not enough, using a USB hub is always a viable option. 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.
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.
The Dell OptiPlex 3070 SFF comes with an HDMI port, while the Fujitsu Esprimo E520 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 Fujitsu Esprimo E520 is better equipped as it comes with 4 SATA slot(s), while the Dell OptiPlex 3070 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 Dell OptiPlex 3070 SFF. Sadly, the Fujitsu Esprimo E520 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 3070 SFF comes with a decent 200 Watt PSU, but the Fujitsu Esprimo E520 has a more powerful one rated at 280 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
