HP ProDesk 400 G2.5 SFF vs. Lenovo ThinkCentre M900 Small

Comparison and Differences

HP_ProDesk_400_G2.5_SFF.jpg case front and back pannel

Lenovo_ThinkCentre_M900_Small.jpg case front and back pannel

Model
Form factor	Small	Small
CPU options	Intel Gen4 i3/i5/i7; Celeron; Pentium;	Intel Gen6 i3/i5/i7; Celeron; Pentium;
Chipset	H81	Q170
Dedicated GPU *	GeForce GT 1030 Low Profile	GeForce GT 1030 Low Profile
RAM	DIMM DDR3-1600	DIMM DDR4-2133
RAM slots	2	4
RAM speed	1600 MT/s	2133 MT/s
RAM max	16 GB	64 GB
USB ports	(2x)USB-A 3.0; (6x)USB-A 2.0;	(8x)USB-A 3.0;
Video ports	DisplayPort; VGA;	(2x) DisplayPort 1.2; VGA;
Other ports	RJ45; Hdph; Mic; Line-Out; Line-In; Serial; (2x) PS2;	RJ45; Hdph; (2x) Mic; Line-Out; Line-In; Serial;
Optional ports	Media card reader; Serial; Parallel;	2x USB-A 2.0; Media card reader (USB 2.0); (2x) PS2; eSATA;
SATA ports	3	3
PCI slots	PCIe x16; PCIe x1;	PCIe 3.0 x16; PCIe 3.0 x1; PCIe 3.0 x16 (wired x4); M2 to PCI adapter (optional);
M.2 slots	N.A.	M.2 (WiFi/BT or PCI extension card)
Drive bays	3.5in; 5.25in (slim)	2.5in; 2.5/3.5in; 5.25in (slim);
PSU	180 W	TFX 210 W
Weight	4.5 kg (9.92 lb)	9 kg (19.8 lbs)
Released	2014	2015
Manual	link	link
Price**	Check Price	Check Price

** As an Amazon associate we earn from qualifying purchases.
* Dedicated GPU warning: Check if your particular power supply model has enough power. Additionally some PSUs don't come with an auxiliary PCIe power connector and you may need to buy a SATA to PCIe power adapter.

Differences between HP ProDesk 400 G2.5 SFF and Lenovo ThinkCentre M900 Small

If you are looking for a more modern desktop, then you should go with the Lenovo ThinkCentre M900 Small which was released in 2015. The HP ProDesk 400 G2.5 SFF 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 Lenovo ThinkCentre M900 Small as it is running a newer generation CPU. This is not to say that HP ProDesk 400 G2.5 SFF is bad - it can still run some powerful CPUs, albeit being an older generation.

Memory

The Lenovo ThinkCentre M900 Small has 4 RAM slots while the HP ProDesk 400 G2.5 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 Lenovo ThinkCentre M900 Small is using the faster 2133 MT/s RAM. The HP ProDesk 400 G2.5 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 Lenovo ThinkCentre M900 Small as it has the ability to run 64 GB of RAM. The HP ProDesk 400 G2.5 SFF can do a bit less at max 16 GB. Most of the times, this should be sufficient for the majority of users.

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.

DisplayPort is crucial for any desktop machine. It is good to see that both models are featuring DisplayPorts. However, the Lenovo ThinkCentre M900 Small comes with 2 ports, while the HP ProDesk 400 G2.5 SFF has only 1. If you are planning to use multiple monitors, the Lenovo ThinkCentre M900 Small is the better choice.

None of the models has an HDMI port. If your monitor supports only the HDMI interface, you will need to buy an adapter. Such adapters are cheap so nothing to worry about.

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 3 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 HP ProDesk 400 G2.5 SFF, nor the Lenovo ThinkCentre M900 Small 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 HP ProDesk 400 G2.5 SFF comes with a decent 180 Watt PSU, but the Lenovo ThinkCentre M900 Small has a more powerful one rated at 210 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.