Fractal Ridge Case PCIe Riser Has Trouble Running in PCIe Gen 4 Mode, Company Outs Workaround

The Fractal Design Ridge SFF tower-type case won critical praise including from us, for its unique design, well-planned interiors, and room for even triple-slot graphics cards with a little adjustments. The case relies on a PCIe riser cable to maintain its SFF form, since the graphics card has to be oriented vertically. The riser included with the case meets PCI-Express 4.0 standards, but end-users started experiencing problems running their latest-generation PCIe Gen 4 graphics cards with this case, with the problem being localized to the riser cable. Fractal investigated this issue, and confirmed the issue.

Apparently, the PCIe riser cable included with the Fractal Ridge, while rated for PCIe Gen 4, has a design flaw that affects signal integrity. The cable is found to be only stable with PCIe Gen 3 or lower. The company is recommending a workaround for end-users while it works on a solution: to confine PCIe to Gen 3 mode using the motherboard’s UEFI setup program (BIOS setup program), in which you can restrict the x16 PEG slot to Gen 3 mode. “We are developing a solution to enable full PCIe 4.0 compatibility, but until that is ready, we will update our listings to reflect that only PCIe 3.0 compatibility is guaranteed,” the company said in a statement.

In this above images from our review of the Fractal Ridge, you’ll see that Fractal’s PCIe Gen 4 riser is a wacky contraption of two PCBs, and the PCIe signal has to change hands twice before reaching your graphics card. The first, larger, rectangular PCB connects to your motherboard’s PCIe slot, and turns it to a 90° angle; while the second shorter PCB slots into this one, and extends the slot to your graphics card, at a 0° angle. A simpler design choice would’ve been to use PCIe Gen 4-rated cables, and a single point of exchange.

Our GeForce RTX 4090 PCI-Express Scaling article should give you a comprehensive look at how much performance you stand to lose by running an RTX 4090—currently the fastest graphics card—in PCIe Gen 3 mode. You lose about 2% performance at 4K Ultra HD when averaged across 25 games from our test bench, so not by much.

The complete statement by Fractal Design follows.

The PCIe riser card supplied with Ridge has been discovered to be incompatible with some hardware configurations when run in PCIe 4.0 mode.

After extensive testing, we have determined that while most systems will run PCIe 4.0 using the Ridge riser card without issue, those experiencing issues with stability will need to run the system in PCIe 3.0 mode for now. This can be enabled in the motherboard BIOS settings.

We are developing a solution to enable full PCIe 4.0 compatibility, but until that is ready, we will update our listings to reflect that only PCIe 3.0 compatibility is guaranteed.

Currently affected users, please contact our customer service team at [email protected] to receive assistance and continuous updates with the latest information until we have a riser replacement available. The customer service team can also help those requiring guidance in switching to PCIe 3.0 mode.

We thank you for your understanding and apologize for any inconvenience.