Read vs Write speeds in upgraded iMac late 2015

[luis2d]

Hello,

First of all, I'd like to thank you for all the useful information you post in this forum. I recently upgraded my late 2011 MacBook Pro with an SSD and my late 2015 iMac with an SSD and Flash drive thanks in part to the advices found in your threads. It's been of invaluable help for me.

So far I'm pretty happy with both my revamped machines but I have a concern with the iMac. These are the specs:

iMac retina 5K, 27 inches, late 2015
3,2 GHz Intel Core i5
16Gb RAM
Boot drive: 128 Gb Samsung MZ-KPW1280/0A6 Flash from a 2017 iMac
Storage Drive: 1Tb Crucial SSD
Graphics: AMD Radeon R9 M380 2048 Mb

The thing is, when I run the Blackmagic disk speed test, selecting the Flash SSD as the target, the writing speed (750) is much lower than the read speed (2500). I wonder if that is normal or if it's due to something I did wrong during the upgrading process.

I would appreciate your opinion.

Thank you in advance,

luis

 

[mbosse]

Hello,

First of all, I'd like to thank you for all the useful information you post in this forum. I recently upgraded my late 2011 MacBook Pro with an SSD and my late 2015 iMac with an SSD and Flash drive thanks in part to the advices found in your threads. It's been of invaluable help for me.

So far I'm pretty happy with both my revamped machines but I have a concern with the iMac. These are the specs:

iMac retina 5K, 27 inches, late 2015
3,2 GHz Intel Core i5
16Gb RAM
Boot drive: 128 Gb Samsung MZ-KPW1280/0A6 Flash from a 2017 iMac
Storage Drive: 1Tb Crucial SSD
Graphics: AMD Radeon R9 M380 2048 Mb

The thing is, when I run the Blackmagic disk speed test, selecting the Flash SSD as the target, the writing speed (750) is much lower than the read speed (2500). I wonder if that is normal or if it's due to something I did wrong during the upgrading process.

I would appreciate your opinion.

Thank you in advance,

luis

This is normal with lower capacity SSDs. Due to fewer flash chips they cannot use all channels of their controller, thus less data is shuffled in parallel.

Best,
Magnus

 

[luis2d]

Thank you Magnus,

I should have gone to 256 or 500Gb then... I will next time : )

Best,

luis