SSD max speed on SATA II

[Andrea Filippini]

Hi everyone,
I have recently upgraded my iMac 21.5-inch late 2009 with SSD and everything is fine.
I have seen however some users with more speed on the same model (for example the video below).

My Black Magic Disk Speed Test is the follow:

SATA II is 3 Gigabit so theoretically up to 375 MB/s.
Any advice?


Best regards
Andrea Filippini

 

[Amsterdamned]

Your speeds look about right, to me. I’ve not installed a SSD into a 2009 iMac but have in a cMP 2009 and my results were similar.

 

[tanventure]

Hi everyone,
I have recently upgraded my iMac 21.5-inch late 2009 with SSD and everything is fine.
I have seen however some users with more speed on the same model (for example the video below).

My Black Magic Disk Speed Test is the follow:

View attachment 932507

View attachment 932519

SATA II is 3 Gigabit so theoretically up to 375 MB/s.
Any advice?


Best regards
Andrea Filippini

Wonder what was the speed for your old HDD? thanks

 

[steve1960]

I just ran Black Magic on my late 2009 MacBook White and hit numbers maybe 10% below yours. Its a cheap Kingston SSD so I would not expect more but as others have said way better than the original HDD.

There are so many factors affecting the performance you get, bus speed in particular. You are seeing an improvement enjoy it or change your Mac.

 

[tyc0746]

The video shows speed quite close to what you're getting (i.e. within 5%) - so it could just be down to the test file size that was used in the video.

3Gbps is the link speed, not the throughput. Throughput is unto 300MBps and 10% will be used on transmission overheads - so max, in the best of the best cases (best SSD, correct file types/sizes, etc.) will be about 270MBps.

 

[steve1960]

If I do the same Black Magic test on my daughters MBA the numbers are much higher. Link speed is higher 6Gpbs so whilst the other factors are very very important so is the initial 'grunt'. If you want faster disc access buy a newer computer.

 

[amaze1499]

See:

Slow SSD write speeds on older iMac

Since my wife got a new iMac I took her old mid-2011 21.5" iMac that has a Samsung 840 Pro SSD installed. After erasing the drive, I installed a fresh copy of Sierra. After loading a few applications, I decided to run Blackmagic disk speed test. The read speeds were ok at 350-400 mbps. The...

forums.macrumors.com

do i have to do sudo trimforce enable on … - Apple Communitydiscussions.apple.com › ... › macOS Mojave


sudo trimforce enable

Use at your own risk.

 

[steve1960]

Is it a size issue? Size is everything? I have another MBA, 2011, with a 2012 replacement OWC SSD in it of 1TB with only 200GB used. No Trim, no issues, Black Magic scores just fine (sorry don't have them to hand).

Does it only matter when you get close to full SSD capacity?

 

[Andrea Filippini]

Wonder what was the speed for your old HDD? thanks

Hi @tanventure ,
previously I had a 5400 rpm 2 TB on Mac OS X 10.6.8
I don't know the speed because Black Magic Disk Speed Test requires newer versions (10.10+).
I have seen similar users with 5400 rpm on YT and the speed was about 50/70 MB/s (write/read).


Best regards
Andrea Filippini
[automerge]1594399136[/automerge]

See:

Slow SSD write speeds on older iMac

Since my wife got a new iMac I took her old mid-2011 21.5" iMac that has a Samsung 840 Pro SSD installed. After erasing the drive, I installed a fresh copy of Sierra. After loading a few applications, I decided to run Blackmagic disk speed test. The read speeds were ok at 350-400 mbps. The...

forums.macrumors.com

do i have to do sudo trimforce enable on … - Apple Communitydiscussions.apple.com › ... › macOS Mojave


sudo trimforce enable

Use at your own risk.

I have read worse performance in boot up with TRIM enabled.
Is it true?


Best regards
Andrea Filippini