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The ProDesk 400 G4 is a 7th Gen Intel (Kaby Lake) business desktop released in 2017. This guide covers RAM compatibility (DDR4-2400), SSD upgrade options, and recommended components for maximum performance.
Available in SFF (Small Form Factor) and Tower variants, the ProDesk 400 G4 supports up to 32GB of DDR4-2400 RAM in the Tower configuration and 16GB in the SFF.
ProDesk 400 G4 Quick Specifications
| Specification | SFF | Tower |
|---|---|---|
| Processor | 7th Gen Intel (Kaby Lake) | |
| RAM Type | DDR4-2400 | |
| RAM Slots | 2 | 2 |
| Max RAM | 16GB | 32GB |
| Storage | 2.5″ SATA + M.2 2280 NVMe (SFF, per HP service guide) | |
| NVMe Support | Yes on SFF (M.2 2280 NVMe, per HP service guide) | |
| PCIe Generation | 3.0 | |
ProDesk 400 G4 RAM Upgrade Guide
Compatible RAM Specifications
The ProDesk 400 G4 requires DDR4-2400 unbuffered DIMMs (UDIMMs). Use non-ECC desktop DIMMs for standard configurations.
Recommended RAM Configurations
| Configuration | Form Factor | Total RAM | Modules |
|---|---|---|---|
| Budget | SFF/Tower | 16GB | 2 × 8GB |
| Standard | SFF | 32GB | 2 × 16GB |
| Standard | Tower | 32GB | 2 × 16GB |
| Maximum (Tower) | Tower | 32GB | 4 × 8GB |
RAM Installation Steps
- Shut down the computer and disconnect all cables including the power cord
- Press the power button for 5 seconds to discharge residual electricity
- Remove the side panel (SFF: slide release latch; Tower: remove thumbscrews)
- Locate the DIMM slots on the motherboard
- Open the retention clips on both sides of the slot
- Align the notch on the RAM module with the key in the slot
- Press down firmly and evenly until the retention clips snap into place
- Replace the side panel and reconnect cables
- Power on and verify RAM is recognised in BIOS (press F10 during startup)
ProDesk 400 G4 SSD Upgrade Guide
The ProDesk 400 G4 supports 2.5″ SATA SSDs and 3.5″ SATA hard drives. The SFF model also has an M.2 2280 slot for NVMe SSDs (HP lists 256GB and 512GB NVMe spares). A SATA SSD upgrade is the most impactful performance improvement you can make.
SATA SSD Installation
- Power off and open the chassis as described above
- Locate the 2.5″ or 3.5″ drive bay
- Mount the SSD using the drive caddy or bracket (SFF models may need a 2.5″ adapter)
- Connect the SATA data cable and SATA power cable
- Reassemble and boot — initialise the drive in Disk Management if it is a secondary drive
Recommended Upgrade Products
| Product | Type | Best For | Link |
|---|---|---|---|
| Crucial 8GB DDR4-2400 UDIMM | RAM | 8GB stick | Shop |
| Kingston Fury Beast 16GB DDR4-2400 | RAM | 16GB stick | Shop |
| Corsair Vengeance LPX 32GB DDR4-2400 Kit | RAM | 32GB kit (2×16GB) | Shop |
| Samsung 870 EVO 1TB SATA | SSD | SATA upgrade | Shop |
| Crucial MX500 1TB SATA | SSD | Budget SATA | Shop |
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Frequently Asked Questions
Q: What type of RAM does the ProDesk 400 G4 use?
A: The ProDesk 400 G4 uses DDR4-2400 unbuffered DIMMs (UDIMMs). The SFF model has 2 DIMM slots supporting up to 16GB, while the Tower model has 2 slots supporting up to 32GB.
Q: Can I add an NVMe SSD to the ProDesk 400 G4?
A: Yes on the SFF model: HP’s service guide lists M.2 2280 NVMe SSDs (256GB and 512GB). You can also upgrade to a 2.5 inch SATA SSD for a significant performance improvement over a traditional hard drive.
Q: Is the ProDesk 400 G4 RAM compatible with the ProDesk 400 series?
A: RAM compatibility depends on the specific generation. The ProDesk 400 G4 uses DDR4-2400, which is physically compatible with other DDR4 systems but the speed rating must match or exceed the motherboard’s requirement.
Q: How do I check how much RAM is currently installed?
A: Open Task Manager (Ctrl+Shift+Esc), click the Performance tab, then select Memory. This shows total installed RAM, speed, form factor, and how many slots are in use. Alternatively, press Win+Pause/Break to open System Information.
Q: Can I mix different RAM sizes in the ProDesk 400 G4?
A: While the ProDesk 400 G4 can technically run with mismatched RAM sizes, it is recommended to use identical modules in pairs for optimal dual-channel performance. Mixing sizes will cause the system to run in flex mode, which reduces memory bandwidth.
Related HP Upgrade Guides
- HP Z2 G9 SFF RAM & SSD Upgrade Guide (2023)
- HP EliteDesk 800 G9 Mini RAM & SSD Upgrade Guide (2023)
- HP EliteDesk 800 G9 SFF RAM & SSD Upgrade Guide (2023)
- HP EliteDesk 800 G9 Tower RAM & SSD Upgrade Guide (2023)
- HP Pro Tower 400 G9 RAM & SSD Upgrade Guide (2023)
- HP Upgrade Guide
Not sure what fits? Use our free Compatibility Checker covering 3,195+ models.
Helpful Guides
Upgrades that fit the HP ProDesk 400 G4 Small Form Factor
What fits: Memory: DDR4-2400 UDIMM, 2 user slots · Storage: M.2 2280; 2.5in SATA drive supported · Charger: internal PSU
Spec source: h10032.www1.hp.com (checked 26 Sep 2026).
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