Dell OptiPlex 5070M vs. Dell Vostro 3881
Comparison and Differences
Differences between Dell OptiPlex 5070M and Dell Vostro 3881
If you are looking for the smaller form factor the Dell OptiPlex 5070M is the right one for you. It is smaller than the Dell Vostro 3881 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 Dell Vostro 3881 as it is running a newer generation CPU. This is not to say that Dell OptiPlex 5070M 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 Dell Vostro 3881 is using the faster 2933 MT/s RAM. The Dell OptiPlex 5070M is slower by supporting RAM speeds of up to 2666 MT/s. Additionally, if you will be needing a lot of RAM, better go for the Dell Vostro 3881 as it has the ability to run 64 GB of RAM. The Dell OptiPlex 5070M can do a bit less at max 32 GB. Most of the times, this should be sufficient for the majority of users.
In total the Dell Vostro 3881 has 8 USB ports. The Dell OptiPlex 5070M 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. What is nice about the Dell OptiPlex 5070M, is that it has 1 USB 3.1 port(s) which allows transfer of up to 10Gb/s. Unfortunately, the Dell Vostro 3881 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 Dell OptiPlex 5070M has a DisplayPort. The Dell Vostro 3881 does not have one? Don't worry though, nowadays video adapters are cheap and you can get almost any combination of conversion types.
The Dell Vostro 3881 comes with an HDMI port, while the Dell OptiPlex 5070M 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 Dell Vostro 3881 is better equipped as it comes with 2 SATA slot(s), while the Dell OptiPlex 5070M has 1 slot(s).
When your goal is to have the fastest SSD transfer speeds, an M.2 interface is crucial. Thus, it is good that both models have M.2 SSD slots. Today M.2 SSDs are not much more expensive than the average SATA drives, so it really does not make sense to invest in SATA drives anymore.
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 Dell OptiPlex 5070M comes with a decent 90 Watt PSU, but the Dell Vostro 3881 has a more powerful one rated at 260 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.