If anyone's unfortunate enough to open the back panel of my work PC, they'll find a glorious nest of SATA wires snaking around cages, and I'll likely be on the receiving end of a lecture on proper cable management and airflow optimization. Storage needs tend to evolve over time, and for most users who have all their M.2 slots occupied, the simplest solution is to just plug in a SATA SSD, just as I have done over three times last year.

I have decided that 2026 is going to be the year I bid adieu to my reliance on the 2.5-inch drives. Instead, I'll be leveraging PCIe bifurcation to add additional terabytes of storage directly to my PCIe rails. Here's why I think it's the perfect solution to my (compounding) storage woes.

I can keep my build clean

And my storage is abundant

The magic that makes this possible is PCIe bifurcation. Since I have an available secondary PCIe slot on my X570 motherboard, I can use it to expand the storage I have using NVMe drives. This can be achieved using a PCIe expansion card to subdivide the primary lanes of the single slot into multiple streams. On a standard motherboard that you get from ASUS, MSI, or Gigabyte, an x16 slot is wired as a singular block of 16 lanes, which means the CPU will only address the expansion card as a singular input. This is where bifurcation is required.

Populating the secondary slot with an expansion card will automatically trigger an x8/x8 split, which, in the process, will halve the bandwidth available to the GPU. I understand how it sounds when I propose halving my available lanes, but the reality is far more forgiving, since this barely affects the GPU's performance at all. As a matter of fact, benchmarks by Puget Systems revealed that reducing the GPU bandwidth from PCIe 4.0 x16 to PCIe 4.0 x8 only led to an average loss of about 3% in performance across a suite of content creation applications. Since this is primarily my workstation, the performance delta is effectively a rounding error compared to the utility of having multiple terabytes of Gen 4 NVMe storage.

Installation is deceptively simple

You just have to know where to look

If you're a regular guest in your BIOS/UEFI settings, getting your additional NVMe drives to work on your PC after installing the expansion card can be as simple as plugging in a USB drive. On most X570 boards, you'd have to head into the Advanced Settings and locate the PCIe configuration menu. From there, you'd have to find the settings for your PCIe x16 slot.

Depending on your motherboard, you may need to switch the slot from Auto to a mode that enables lane splitting. For me, this was labeled as PCIe RAID mode, but you may see a bandwidth configuration in its place. This allows the CPU to allocate the appropriate lanes to each NVMe drive on the adapter.

Once that is done, all that's left to do is save and reboot. Back in your OS, you just need to open Disk Management, and your newly installed NVMe drives should appear at this step.

Why not just buy a bigger NVMe?

Reinstalls and migrations are a hassle

The most common counter-argument I've encountered while talking about this solution is "Why not just buy a single 4TB NVMe and call it a day?"

While a single, high-capacity drive is the most logical and the cleanest solution, it can quickly become a logistical nightmare thanks to OS reinstallations and migrating large files that are already on my existing NVMe drives. Moving to a larger primary drive would involve hours of system-level reconfiguration, setting up the software I use every day, and the inevitable re-authentication that comes with it when all I want is some additional storage.

PCIe bifurcation affords me exactly the level of plug-and-play convenience that I'm looking for, which will involve popping open the case, seating the expansion card, and toggling a BIOS setting for instant storage.

It's not for everyone, though

While it's a useful feature to have, PCIe bifurcation isn't a universal fix, and it most certainly isn't a beginner's upgrade. Not every motherboard will support lane splitting, not every BIOS will expose the options clearly, and not every user will want to tinker with firmware settings to add storage. There's also the trade-off involved with populating a secondary x16 slot, which drops the GPU to x8, which, while it carries negligible impact on workstations, can matter in GPU-bound gaming scenarios or on other PCIe generations. If all of those things matter to you, it's best to stick with easier storage expansions on the market.