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I’ve purchased M.2 PCIe SSD which has official speeds 1300MB/s Write - and 3000M/s reads + I’ve bought adapter and drive has 650MB/s in reads and 750MB in write. What are max speeds on iMac 27 2013 PCIe - not Apple SSD - but just PCIe Thank You :)
Review this guide: The Ultimate Guide to Apple’s Proprietary SSDs The I/O speed of your SSD and what the system has for an interface limits the throughput. The 2013 iMac PCIe interface is limited to mSATA III (6.0 Gb/s) interface (Red) as you can see here in this interface breakdown. Be aware a PCIe/AHCI or PCIe/NVMe drive and adapter won’t work in this system.
