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Intel Z790 Motherboards with PCIe Gen5 M.2 Support

January 12, 2023 Hardware, Motherboards

Although there are zero Gen5 SSDs in the market at this point, you may still want a straightforward upgrade path for such a drive when building a new system based on Raptor Lake and Z790 in early 2023. SSDs that can utilize the additional bandwidth are just around the corner, after all.

While AMD made a PCI Express 5.0-enabled M.2 slot mandatory on X670 and even B650 motherboards, Intel’s high-end Z790 chipset only brings Gen5 PCIe lanes to the graphics card slot by default. Adding Gen5 M.2 support is still possible by having it share bandwidth with the GPU, but whether or not to do so is ultimately up to the motherboard manufacturers.

You will probably not be surprised to learn that most manufacturers have opted to treat the Gen5 M.2 slot as something of a premium feature in the first batches of Z790 motherboards. Many mainstream and semi-premium models that tend to be popular among gamers, such as the Asus Strix-A/F, MSI MAG Tomahawk, and Gigabyte Aorus Elite, are notably lacking this feature/compromise.

ASRock is a bit more generous, however, and there are a few other exceptions. So, if this feature is at least somewhat important to you – but not worth burning through most of your budget on – you still have options. That said, there are no particularly cheap Z790 boards (it is the high-end chipset after all), and no boards with a combination of both Gen5 M.2 and DDR4 support. 

Gigabyte Z790 Boards with Gen5 M.2

For now, Gigabyte offers Gen5 M.2 slots only with the two E-ATX Aorus models, and the creator-oriented Aero G model. The more mainstream Aorus Elite and Gaming X varieties use the standard configuration with PCIe 4.0 M.2s and one PCIe 5.0 x16 GPU slot.

Asus Z790 Boards with Gen5 M.2

As their names imply, the Maximus boards are pretty much maxed out as far as connectivity goes. They come with two full-length PCIe 5.0 slots (running at x8/x8 if both are used) and also expand the M.2 storage options via a bundled add-in card and/or DIMM-to-M.2 module. Nevertheless, due to the chipset limitations, there’s just one PCIe Gen5 M.2 slot.

The popular RoG Strix lineup also tends to be full-featured, but only the Z790-E and the mITX model Z790-I have the option to add a Gen5 SSD. Unfortunately, the Z790-F and Z790-A are lacking in that department and the same goes for all TUF- and Prime-series boards (and the single ProArt) released so far.

MSI Z790 Boards with Gen5 M.2

MSI also reserves PCIe 5.0 SSD support for mainly the enthusiast models, but the traditionally more mainstream MPG Carbon board also gets a full set of storage options. On the other hand, the Z790 Carbon WiFi seems to be more geared toward the premium end of this generation, which is not least reflected in the price tag.

Notably, the ultra-premium E-ATX Z790 Godlike is equipped with no less than seven M.2 slots, but only one of them offers four lanes of Gen5 greatness.

ASRock Z790 Boards with Gen5 M.2

What sets ASRock apart is that even its first mainstream Z790 motherboards include a Gen5 M.2 slot. Of course, this is not without some compromises in other areas such as a lack of wireless LAN and seemingly less powerful power delivery solutions. ASRock’s E-ATX Taichi (and nearly identical Taichi Carrera) is also not a ‘spare-no-expenses’ model like the MSI Godlike but still includes Thunderbolt 4. Interestingly, the latter is also true for the comparatively inexpensive Z790 LiveMixer. 

What are the tradeoffs?

Leading up to the launch of Raptor Lake and the Z790 chipset, there were rumors back and forth about support for Gen5 SSDs. It was eventually revealed that the new platform would indeed not offer PCIe 5.0 bandwidth for anything but the full-length primary slot, which normally houses the GPU. This is arguably an odd design choice, seeing as no graphics card today or in the near future is likely to require 16 lanes of PCI-Express 5.0 bandwidth.

To enable Gen5 bandwidth for an M.2 SSD slot (PCIe 5.0 x4), the apparent solution is therefore to split the lanes of the full-length x16 slot and reduce it to PCIe 5.0 x8. This is still more than enough bandwidth for any current-gen GPU.

However, for the same reason, there are no PCIe 5.0-enabled graphics cards on the market – not even the RTX 4090 or RX 7900 XTX use the new interface. The potential problem this poses is that current-gen GPUs will have to make do with PCIe 4.0 x8, which is equal to PCIe 3.0 x16. Fortunately, this still seems to be enough even for high-end GPUs of this generation – at least in a vast majority of cases, as demonstrated here by GamersNexus: