An AMD WRX90 motherboard uses DDR5 ECC registered memory, known as DDR5 ECC RDIMM. It has eight memory slots and eight memory channels, and you fill all eight with identical modules. That one sentence answers most of the question, and this page covers the rest: what the type means, what does not work, how fast it runs, and how to pick the size.
The short answer
- Type: DDR5 ECC RDIMM.
- Slots: eight, one per memory channel.
- Speed: set by the processor, up to 6400 MT/s with a Threadripper PRO 9000 WX and up to 5200 MT/s with a 7000 WX.
- Capacity: ASUS, ASRock, GIGABYTE and Supermicro list up to 2TB on their WRX90 boards. Check the capacities in our listings for what we supply.
What works and what does not
| Memory type | Used on WRX90? | What the vendor pages say |
|---|---|---|
| DDR5 ECC RDIMM | Yes | Listed by ASUS, ASRock, GIGABYTE and Supermicro |
| DDR5 ECC RDIMM-3DS | Yes, on ASRock | ASRock lists RDIMM and RDIMM-3DS |
| DDR5 UDIMM, with or without ECC | No | Not listed. ASRock states standard desktop DDR5 is not supported |
| DDR4 of any type | No | ASRock warns that DDR4 and older modules must not go in the DDR5 slots |
If you are coming from a gaming or desktop build, the biggest change is the module type. Desktop memory is unbuffered. WRX90 uses registered modules, which have a register chip that lets a board carry more memory per channel with a stable signal. The memory types explained guide covers each type, and the ECC vs non-ECC guide explains the error correction.
How fast the memory runs
| Processor | Memory speed listed | Source |
|---|---|---|
| Threadripper PRO 9000 WX | Up to 6400 MT/s | GIGABYTE MH53-G40 page |
| Threadripper PRO 7000 WX | Up to 5200 MT/s | GIGABYTE MH53-G40 page, Kingston |
The module speed printed on the label is a ceiling. The processor decides what the system runs. Faster modules on a 7000 WX system run at the 7000 WX speed, so do not pay for speed the processor cannot use. Some boards also list overclocked settings above these figures, for example ASRock lists up to 7600+ with overclocking, but those are not a standard operating speed.
How to choose the size
- Decide the total memory you need. The AI workstation RAM guide shows how to size it from your workload.
- Divide by eight. That is the size of each module. A total of 512GB means eight modules of 64GB.
- Buy matched modules, eight of the same type, speed and size, to fill every channel.
- Check the board and processor. Look up your board's memory list and your processor's speed before you order.
Which WRX90 board do you have?
The memory type is the same on every WRX90 board, so the question is only which exact board and processor you own. Our WRX90 motherboard comparison covers the main boards, and the AMD WRX90 memory guide covers workstations that use them. For board specific details, read the ASUS Pro WS WRX90E-SAGE SE memory guide or the ASRock WRX90 WS EVO memory guide, or go straight to the ASUS and ASRock listings.
Find WRX90 memory
Browse DDR5 RDIMM or the Threadripper motherboard memory collection. If your board is not listed, send us the model name and we will check it.
Frequently asked questions
What RAM does an AMD WRX90 motherboard use?
DDR5 ECC RDIMM, in eight slots that match the eight memory channels. Fill all eight with identical modules for full bandwidth.
Can a WRX90 board use regular desktop DDR5?
No. ASRock states that standard desktop DDR5 is not supported, and the ASUS, GIGABYTE and Supermicro pages list ECC registered memory only.
Can I use DDR4 on a WRX90 board?
No. WRX90 boards have DDR5 slots, and ASRock warns that DDR4 and older modules must not be installed in them.
How many memory modules does a WRX90 board need?
Eight for full bandwidth, one in each slot. Fewer modules work, but they use fewer channels.
How much RAM can a WRX90 board hold?
ASUS, ASRock, GIGABYTE (WRX90 AI TOP) and Supermicro list up to 2TB. Check the page for your own board.
Sources
ASUS Pro WS WRX90E-SAGE SE, ASRock WRX90 WS EVO retailer listing, ASRock WRX90 WS EVO manual, GIGABYTE MH53-G40, Supermicro H13SRH and Kingston memory for the ASUS WRX90E-SAGE SE, read on October 29, 2026. Specifications change, so confirm against your board maker's documentation.
Buying memory for workstation fleets
NEMIX RAM is a US-based memory specialist, in business since 1993. Every module is researched, matched, and compatibility-tested by NEMIX RAM, is JEDEC-compliant, and is backed by a lifetime warranty; register your purchase to activate it. Purchase orders, net terms and volume pricing are available for engineering, reseller and public-sector orders. Request a quote with your models and quantities, or contact our sales team.
NEMIX RAM is an independent memory supplier and is not affiliated with the companies named here. AMD, Threadripper, ASUS, ASRock, GIGABYTE, Supermicro and Kingston are trademarks of their respective owners, used here only to identify sources and compatible systems.