Dell XPS 8700 vs. Dell XPS 8900
Comparison and Differences
Differences between Dell XPS 8700 and Dell XPS 8900
If you are looking for a more modern desktop, then you should go with the Dell XPS 8900 which was released in 2015. The Dell XPS 8700 is older and entered production in 2013.
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 XPS 8900 as it is running a newer generation CPU. This is not to say that Dell XPS 8700 is bad - it can still run some powerful CPUs, albeit being an older generation.
Memory
Both models have have equal amount of ram slots (4 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 XPS 8900 is using the faster 2133 MT/s RAM. The Dell XPS 8700 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 XPS 8700 can do a bit less at max 32 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 XPS 8700 is inferior in this regard and packs 9 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 slots are located on the motherboard and it is where SSD, HDD and Optical Disk Drives are connected. Each of the two models being compared have 5 SATA slot(s). Keep in mind that having too few SATA slots might limit your options for connecting additional memory drives.
M.2 SSD interface allows you to transfer data with higher speeds compared to the old SATA interface. Unfortunately, neither the Dell XPS 8700, 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
Looking at the Power Supply Unit (PSU) of the two models we don't see any differences. For either of them you get a maximum power of 460 Watts. However be careful, many models have more than one power supply option. When buying your computer, it is a good idea to get a version with the most powerful PSU. This will potentially allow you to upgrade to a more powerful GPU for example.