Summary of Server Differences
If drive density is your most important need, the Dell PowerEdge R740xd2 is the server for you when compared to the Dell PowerEdge R740. The R740xd2 is more expensive than the R740, but you get 26 3.5‑inch drives stuffed into a 2U chassis. There is also an option for 16 3.5‑inch drives plus 10 2.5‑inch drives for workloads that want to tier their storage. That extra storage does come at a price. You have to give up eight memory slots, three PCI slots, and GPU support. With memory sizes increasing, having to give up a few slots may be worth it to get the drive density of the R740xd2.
On the other hand, if you do not need that drive density, the R740 is a great, well‑balanced server with a lot of power. You save a good amount on the base chassis compared to the R740xd2 and can save more by using a larger number of smaller memory DIMMs. Most of our customers don't need the extra connectivity of the R740, but it is the clear winner if you need the eight PCIe slots.