Ram compatibility

[Krys67]

I have Ram 8 modules: 24GB 3Rx4 PC3L-10600R-09-12-ZZZ-D4

M393B3G70DV0-YH9Q2 E (Samsung made in china Hp approved). 

Not working in my workstation (Z420 Workstation). Is this compatible ram for my pc? will Bios update help?

[NonSequitur777]

@Krys67,

Welcome to our HP Community forum!

The compatibility of your RAM modules (Samsung M393B3G70DV0-YH9Q2) with the HP Z420 depends entirely on which version of the Z420 motherboard you have. Whilst the official manuals state the Z420 only supports ECC Unbuffered (UDIMM) memory, we have verified that the "v2" revision of the motherboard can successfully run ECC Registered (RDIMM) memory, such as 4x16GB Samsung M392B2G70DM0-CMA DDR3 SDRAM RAM sticks designed for servers and workstations. It features a speed of 1866MHz (PC3-14900R), a 240-pin form factor, 2Rx4 dual-rank configuration, and ECC Registered (RDIMM) technology with a CAS latency of CL13 at 1.5V I used in my HP Z420 Workstation upgrade project: HP Z420 Workstation Performance Results - UserBenchmark.

Where do you go from here?

1. Check your Motherboard Version:

The most critical step is to check your BIOS Boot Block Date. This date is hardcoded and cannot be changed by a software update. To find it, go into the BIOS (F10 during startup) and check System Information:

• Version 1 (2011 Boot Block): Does NOT support Registered (RDIMM) RAM. Your current 24GB modules will never work with this board.
• Version 2 (2013 Boot Block): Supports Registered (RDIMM) RAM. If you have this date (typically 03/06/2013), your motherboard is technically capable of running server memory.

2. The Issue with your Specific RAM:

However, even if you have a v2 motherboard, your specific modules may still fail for the following reasons:

• Ranking (3Rx4): Your modules are Triple Rank (3Rx4). The Z420 is much more stable with Single Rank (1R) or Dual Rank (2R) modules. High-rank memory (3R or 4R) often prevents the system from completing the POST (Power-On Self-Test).
• Module Capacity (24GB): Whilst the Z420 v2 can handle 16GB RDIMMs (up to 128GB total), 24GB modules are non-standard for this platform. Using 8x16GB is a verified 128GB configuration. 

3. Will a BIOS update help?

A BIOS update (to version 3.90 or later) is highly recommended if you have a v2 board, as it improves memory training and support for newer hardware. However, if you have a v1 board, no update will make it compatible with Registered RAM.

Summary Recommendations:

• If you have a v1 board: You must replace your RAM with PC3-12800E (ECC Unbuffered) modules.
• If you have a v2 board: Trade your 3Rx4 24GB modules for 2Rx4 16GB Registered modules.
• Mixing Types: Even if you only use one of these sticks, it will fail because the Z420 motherboard specifically looks for ECC UDIMMs for standard operation.

What is the Boot Block date listed in your BIOS?

Kind Regards,

NonSequitur777