I'm trying to set up an external solution since I've maxed out my ports. I have a Crucial T700 NVMe PCIe 5.0 SSD, but I've heard that many current enclosures might bottleneck its performance. I'm considering getting the Acasia 80Gbps enclosure, but then I found out that its compatibility is mainly for PCIe 4.0 devices. A retailer mentioned that PCIe 4.0 uses 128b/130b encoding, and Thunderbolt 5 can't process the PAM4 modulation of PCIe 5.0. Does this mean my PCIe 5.0 SSD won't fit in the enclosure? I was under the impression that these devices are backwards compatible, just at lower speeds.
2 Answers
Thunderbolt 4 supports up to PCIe 4.0 speeds, so you're right there. If you're using a PCIe 4.0 enclosure, it'll likely work, but you won’t get the full performance of the PCIe 5.0 SSD. It may recognize the SSD but could limit its capabilities, kinda like plugging a high-speed race car into a city street—still works but doesn't go full throttle!
Yeah, the backwards compatibility is a bit tricky here. Even though PCIe 5.0 is supposed to be backwards compatible, the enclosure you're looking at is primarily designed for PCIe 4.0. There might be issues with the signal compatibility, so while it might fit physically, it might not be able to properly utilize your SSD. Best to check with the enclosure specs before buying.
Thanks for clarifying! I guess I'll need to look at other options if I want to harness the full speed.