The Micron 9400 Pro 32TB-class SSD is transformational for this generation of servers and storage. PCIe Gen4 servers have been around since 2019, and over the last quarter, we have started to see PCIe Gen5 servers from Intel’s “Sapphire Rapids”, to AMD’s EPYC “Genoa”. This new generation of servers brings with it the ability to realistically include the CPU cores, memory, networking, and accelerators to consolidate at ratios of 2:1 to 4:1 over 5-year-old servers. With such a transformative era of servers and storage platforms, the Micron 9400 Pro seeks to introduce more performance and more capacity to aid in next-generation architectures.
As a quick disclosure and teaser, Micron sent us these drives and supported this piece. The company requested that we test these drives on a variety of different platforms. We did this with 17 different architectures, including the newest AMD, Intel, and Marvell (Arm DPU) PCIe Gen5 platforms. Since we have to pay someone in the data center to take drives out and put them into new machines once a day for over two weeks, Micron supported that effort. As with everything on STH, Micron did not get to preview this article, and it was done editorially independently.
As a quick update, we added a video version of this review about a week after it went live. You can find that video here:
There was a lot of interest in the web version of this article, so we decided why not make a video version as well. As always, check it out in its own tab, browser, or app for the best viewing experience.
Micron 9400 Pro 32TB Overview
We wanted to start this review with a recap of the specs. First, we are calling this a 32TB NVMe SSD. While there is NAND to support a 32TB capacity, the drive itself is actually a 30.72TB NVMe SSD. Overprovisioning is common in the data center SSD industry. While we are looking at the 32TB-class 2.5″ U.3 15mm drive, that is just one capacity point that the company offers. Micron sent us its flagship.
Micron’s positioning for the 9400 series is as a high-performance drive for cloud and enterprise servers. These are drives meant for single PCIe x4 hosts, not dual-ported applications. These drives also utilize Micron’s 176-Layer TLC NAND. There are many drives in the market utilizing QLC trading performance for better cost per TB of capacity. That is not the market Micron seeks here. Instead, these are designed to be the highest-performing PCIe Gen4 x4 NVMe drives on the market.
As drive capacities have grown, appetites for 7+ DWPD drives have shrunk. Writing 30.72TB to a drive consistently every day is considerably more than most SSDs will experience in the field. That is almost 1PB/ month of endurance.
We know that folks are very sensitive to endurance ratings. Years ago, when we did our Used enterprise SSDs: Dissecting our production SSD population, we found even smaller capacity SSDs were running much lower than their rated endurance. As an excerpt from that piece:
These were much smaller SSDs, but we are now talking SSDs with tens of PBs of write endurance, even with 1 DWPD, so it has become a smaller issue these days. If one does need more write endurance, the Micron 9400 Max would be Micron’s solution at 3 DWPD.
Micron has the 9400 MAX series that offers even more performance but at the cost of some capacity. Instead of getting 30.72TB at the top-end after over-provisioning with the 9400 Pro, one gets 25.6TB using the 9400 MAX series. That extra spare area is not just about the 2.5x increase in endurance figures (since the 3 DWPD is off of a smaller base capacity.) Instead, the MAX series is a higher-performance series than even what we are looking at today.
This year, we expect the market to still be mostly 2.5″ U.2 and U.3 drives in this segment, but in the future PCIe Gen5 generation we expect more EDSFF. Still, for this generation of servers, we expect 2.5″ to be dominant as primary server storage in enterprise servers.
Let us now transition to performance.