HP ProDesk 400 G4 review: specs, options & used prices

What this machine is

The HP ProDesk 400 G4 belongs to the class of machines that filled offices for years and now fills the secondary market — practical, repairable, and priced accordingly.

Business-line machines are the backbone of the secondary PC market for a practical reason: they were sold in large volumes to offices, serviced professionally, and then retired in bulk.

Tracked used listings cluster around a median of $80 (9 active listings at the time of writing).

Configurations you will actually see

The CPU options we track for the ProDesk 400 G4 are the Core i5-6500, Core i5-7500 and Core i5-8500T. Intel Core options span the 6th to 8th generations. Earlier generations predate official Windows 11 support — check the specific CPU in each listing. T-suffixed variants are the lower-wattage versions of the same chips: cooler and quieter, a little slower.

Memory options run from 4 GB to 8 GB (4 GB, 8 GB). For a current operating system, treat anything below 8 GB as a first upgrade, not a final configuration.

Solid-state storage options include 128GB SSD, 240GB SSD, 256GB SSD and 500GB SSD.

Hard-disk listings (1TB HDD) also exist — an SSD remains the single most noticeable upgrade on this class of machine.

Upgrade path and running costs

The compact chassis accepts standard low-profile parts, and drive bays are typically accessible without tools. The trade-off is a small, often proprietary power supply — check it before planning any graphics add-on.

Our compactness rating for this chassis: 75/100 — compact by design.

Who it fits

If the task is browsing, office documents, video calls, or a kiosk/POS role, the ProDesk 400 G4 does the job at a low sensible price. Some configuration options predate official Windows 11 support — check the specific CPU if a modern OS baseline is required.

The spec sheet carries the full option ladder and tracked prices; for context, browse the desktop catalog or the HP desktops page.

Verdict

Judged as a tool rather than a toy, the ProDesk 400 G4 holds a clear niche at the sensible end of the used market.

Buy it when you need a cheap, repairable machine for its class of work, and verify the configuration before paying — RAM and storage vary widely between listings. Tracked prices span $65 to $120, and most of that spread is configuration, not condition.

Our composite LB Score currently sits at 12/100 — a score that mostly reflects the platform age — use it to compare like with like, not against modern hardware.