What's going on with PCIe 4.0 x4 to M.2 Cards? What gives?

Hardware
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Hello everyone,

Anyone know what’s going on with PCIe 4.0 x4 to M.2 Cards? Literally every card seems to be listed as PCIe 3.0, now I know these cards basically just breakout the M.2 pins to the correct PCIe lanes but only some have the traces in tolerance for PCIe Gen 4. So anyone find cards that “say” 3.0 but work fine with Gen4? Also a lot of these cards listed for sale, especially on Amazon seem super sketchy, like bad QC that’s going to blow out a PCIe lane. Why can’t anyone reputable make a card?

Anyways starting to rant, post your experiences and suggestions.

Cheers!

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The ASUS card seems to be the go to from what I’ve seen. There is a PCIe 3.0 version and PCIe 4.0 version. However AFAIK your motherboard needs to support 4x4 bifurcation to get all four slots.

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Isn’t it just that the v4 is relatively new, and even v3 didn’t shift a Lot of units. Not none, but not massive amounts?

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I use the ASUS Hyper M2 Gen4 card with gen4 devices, it works with gen4 speeds. It might also be that some of the gen3 bifurcation cards works well with gen4, but the manufacturers never bothered testing again when gen4 came out, nor update the specs. That’s no help if you want warranty backing for using a card with gen4, of course.

I remember that the YT channel BuildOrBuy at some point tested Supermicro’s PCIe x8->2*M2 x4 gen3 card with gen4 devices, and got gen4 links without hassle (don’t know the exact model, check the YT channel). But again, this won’t help you get warranty.

In theory, shorter physical distance through the wires should be better for gen4. The ASUS gen3 card that @cowphrase links has the four M.2 slots stacked from the slot and up, translating to fairly long wires for the topmost device. The gen4 version fixes this by orienting the slots diagonally, with all the M.2 connectors near the PCIe connector. This might have been required to keep up with the link speed.

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Nope. I tried.

Also, I didn’t realize that the Gen4 card is significantly longer than the Gen3 card. That’s important to know if your case is space limited.

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I would second the recommendation for the Asus Hyper M.2 gen 4. Gen 4 speed, wide motherboard support, and can be had for under $100… don’t overthink this

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Rocking a pair of the ASUS gen4 cards right now and they work great.

Gigabyte and MSI also make versions that are decent. The MSI one I was only able to get by buying a TRX40 motherboard but Gigabyte’s are available retail.

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