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Imac 27 late 2014 5k upgraded to NVME WD BLACK 750 But no more then 700 read and write. WHY???
- Thread starter DINCAO
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2014 iMac has a 2-lane slot for the PCIe bus. Theoretical max is about 1,000 MBps. (5.0 GT/s PCIe x2)
Your W-D black card would be pretty fast, but is limited by bandwidth of the slot in that 2014 iMac.
It would be much faster in the Late 2015 iMacs, which provide 4-lanes on the PCIe bus, which looks like it should allow speeds up to about 3,000 MBps. (8.0 GT/s PCIe x4)
Downgrade if you like. That won't change the hardware in your 2014 iMac -- you would still have speeds in about the same range. (which is still plenty fast!)
Your W-D black card would be pretty fast, but is limited by bandwidth of the slot in that 2014 iMac.
It would be much faster in the Late 2015 iMacs, which provide 4-lanes on the PCIe bus, which looks like it should allow speeds up to about 3,000 MBps. (8.0 GT/s PCIe x4)
Downgrade if you like. That won't change the hardware in your 2014 iMac -- you would still have speeds in about the same range. (which is still plenty fast!)
Check PCIe link rate and link width in the PCI tab of System Information.app
Your iMac has Thunderbolt 2 ports supporting 20 Gbps. You might be able to get near PCIe 2.0 5GT/s x4 speed (≈ 1500 MB/s) by using an NVMe in a Thunderbolt 3 or Thunderbolt 2 enclosure.
Your iMac has Thunderbolt 2 ports supporting 20 Gbps. You might be able to get near PCIe 2.0 5GT/s x4 speed (≈ 1500 MB/s) by using an NVMe in a Thunderbolt 3 or Thunderbolt 2 enclosure.
