iMac 5K (Late 2015): Flash Drive (SSD)

2015-11-19 • SEND FEEDBACK •
Related: 2013 Mac Pro, 2015 iMac 5K, 4K and 5K display, computer display, iMac, iMac 5K, Mac Pro, Macs, memory, Other World Computing, SSD

Get iMac 5K at B&H Photo and see also MPG’s computer gear wishlist.
See also diglloyd-recommended performance packages for iMac at OWC.

Save money on 32GB or 64GB OWC memory (about $400 savings vs Apple!)

MPG recommends this iMac 5K: 27" Retina 5K Display, 4.0 GHz Intel Core i7 (Skylake), 1TB Flash, 8GB memory, AMD Radeon R9 M395X GPU (4GB GDDR5) + 32GB or 64GB OWC memory.

It’s worth paying for the Apple 1TB flash drive—wow!

Sustained transfer speed, large transfers

The late 2015 iMac 5K Retina has a stunningly fast flash drive (SSD) that trounces the flash drive in the 2014 iMac 5K.

2013 Mac Pro: writes at ~930 MiB/sec and reads at ~1180 MiB/sec.
(early 2014 build, 2015 builds may be faster)
2014 iMac 5K: writes at ~716 MiB/sec and reads at ~766 MiB/sec.
2015 iMac 5K: writes at ~1520 MiB/sec and reads at ~2080 MiB/sec.

One reader reports that the 2013 Mac Pro built in 2015 may have a faster flash drive than shown here—this seems likely but MPG has not confirmed it.

Real world speeds through the file system using diglloydTools DiskTester.
disktester run-sequential --test-size 8GB

Flash Drive (SSD) Sustained Transfer Speed for larger transfers
Late 2015 iMac 5K 4.0 GHz Radeon M395X vs 2013 Mac Pro 3.3 GHz 8-core D700 and 2014 iMac 5K

Sustained transfer speed vs transfer size

Transfer speed with 32K transfers is about 750 MB/sec, which is outstanding, and well beyond the bus speed of any SATA 6G SSD. Wow! It is also very important for many tasks which make small transfers (including file copying). But it gets even better: speed picks up even more with larger transfers.

Flash Drive (SSD) Sustained Transfer Speed for larger transfers
Late 2015 iMac 5K 4.0 GHz Radeon M395X vs 2013 Mac Pro 3.3 GHz 8-core D700 and 2014 iMac 5K