[SOLVED] PCIE Gen3 x8 to Gen4 M.2?

Kev1n8088

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May 20, 2020
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With the (almost) 5gb/s speeds of PCI-E Gen4 M.2 drives, I would love to use them for my system. The problem is I don't have an X570 System and don't fancy swapping out my entire CPU and Mobo for a drive. Looking at the specs, a PCI-E Gen3 x8 lane would mean the same speed as a Gen4 x4 lane, which is what an M.2 uses. Is it possible to convert a gen3 x8 port into a gen4 x4 M.2 port?
 
Solution
The difference between a Gen 3 and a Gen 4 PCIe drive is seen only if copying a large batch of sequential data between two of them

Gen4 -> Gen 4 would be somewhat 'faster' than Gen3 -> Gen3.

In the VAST majority of uses cases, in motherboards than natively support the Gen 4...you'd see little if any difference over a Gen3.

For most uses, even the difference between a good SATA III drive and Gen 3 is invisible.

Don't go through any gyrations trying to make a Gen4 be magically faster on a board that does not natively support it.

(and no, you can't just magically convert it)
The difference between a Gen 3 and a Gen 4 PCIe drive is seen only if copying a large batch of sequential data between two of them

Gen4 -> Gen 4 would be somewhat 'faster' than Gen3 -> Gen3.

In the VAST majority of uses cases, in motherboards than natively support the Gen 4...you'd see little if any difference over a Gen3.

For most uses, even the difference between a good SATA III drive and Gen 3 is invisible.

Don't go through any gyrations trying to make a Gen4 be magically faster on a board that does not natively support it.

(and no, you can't just magically convert it)
 
Solution
Is it possible to convert a gen3 x8 port into a gen4 x4 M.2 port?

Yes, but it's extremely expensive. When Tom's Hardware previewed the Phison E16 prior to the release of X570 they had to convert PCIe 3.0 lanes to PCIe 4.0, and the device they used cost $20,000. 4.0 is more common now and you can get PCIe switches but it's still cheaper to build a new system.

Not that it matters, current 4.0 drives are meh-worthy.