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nkurtar

macrumors member
Original poster
Sep 13, 2019
47
13
Istanbul, Turkey
I have a i9 2019 iMac with 1 TB SSD. I get one day 1.9 MB/s write and 2.5 MB/s read and other day 1.7 MB/s write and 1.9 MB/s read. Sometimes it gets down to 1.6 MB/s write and 1.3 MB/s read. Sometimes it gets up to 2 MB/s write and 2.6 MB/s read. Why is it that I get these inconsistent results? Anybody with same experience?
 

mmomega

macrumors demi-god
Dec 30, 2009
3,879
2,089
DFW, TX
Try AJA System Test
it is an alternative to blackmagic.
I had similar issues years ago with blackmagic, discovered AJA and have been using it exclusively since.


also on the Mac App Store

This just gives you a secondary testing method and more data to determine if this is the blackmagic software a different issue.
 

kohlson

macrumors 68020
Apr 23, 2010
2,425
736
I am curious about the numbers you're reporting. On my 2013 MBP, I get 870MB/x write and 1470 MB/s read. Perhaps you're not including zeros?
In any event, disk test performance can depend on what else is going on in your system, such as Spotlight indexing, background (or foreground) downloads from open web pages, and so on. You should get pretty consistent results, assuming nothing else is contending form disk activity.
 

nkurtar

macrumors member
Original poster
Sep 13, 2019
47
13
Istanbul, Turkey
One more thing: Before upgrading my ram to 72 GB from 8 GB, I was getting consistent 1900 MB/s write and 2500 MB/s read. After upgrade inconsistency started.
 
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