Dell OptiPlex 3040 SFF vs. Dell XPS 8900
Comparison and Differences
Differences between Dell OptiPlex 3040 SFF and Dell XPS 8900
Both computers, the Dell OptiPlex 3040 SFF and the Dell XPS 8900, were released during the same year - 2015.
If you are looking for the smaller form factor the Dell OptiPlex 3040 SFF is the right one for you. It is smaller than the Dell XPS 8900 and will fit more easily under your desk.
Processor
The two models have the same generation of Intel processors. We think that the 6 generation of Intel Processors have enough power to execute all of the home and office tasks that most people will care to do.
Memory
The Dell XPS 8900 has 4 RAM slots while the Dell OptiPlex 3040 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 XPS 8900 is using the faster 2133 MT/s RAM. The Dell OptiPlex 3040 SFF is slower by supporting RAM speeds of up to 1600 MT/s. Additionally, if you will be needing a lot of RAM, better go for the Dell XPS 8900 as it has the ability to run 64 GB of RAM. The Dell OptiPlex 3040 SFF can do a bit less at max 16 GB. Most of the times, this should be sufficient for the majority of users.
Ports
In total the Dell XPS 8900 has 10 USB ports. The Dell OptiPlex 3040 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. 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.
In case your monitor supports HDMI only, you will be happy to hear that both models come with an HDMI port.
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 XPS 8900 is better equipped as it comes with 5 SATA slot(s), while the Dell OptiPlex 3040 SFF has 2 slot(s).
M.2 SSD interface allows you to transfer data with higher speeds compared to the old SATA interface. Unfortunately, neither the Dell OptiPlex 3040 SFF, nor the Dell XPS 8900 has one. However, you can still use a SATA SSD drive which should give you satisfactory performance.
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 3040 SFF comes with a decent 180 Watt PSU, but the Dell XPS 8900 has a more powerful one rated at 460 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
