2019 27" iMac SSD Read/Write Speeds

[spiderpumpkin]

I just ordered a 512GB SSD with my i9 27" iMac but I'm wondering how much faster the 1TB SSD would be.

What results are you getting when testing the 512, 1TB and 2TB SSD speeds with Blackmagic Speed Test?

 

[AppleFan360]

On my 2TB SSD inside I'm getting around 2000 mb/s read and write.

 

[tyc0746]

OE 1TB SSD

1934mbps write
2635mbps read

 

[hfg]

2019 iMac i9 with 2TB SSD:

 

[bondavi]

512GB SSD

 

[rvivancoITA]

i9 with 512Gb

by the way, why do we have different values for the same GB of disk? I read above from another one that got a higher value than mine....

 

[mikehalloran]

I’ve never seen two units test identically. As long as they’re within range, real world performance will be the same.

 

[macduke]

My 2TB was around 2GB/s write and 2.5GB/s read. Pretty fast but I was hoping it would be at least as fast as the 2018 MBPs.

 

[miqui]

Do you have any idea why iMac’s SSD is slower than those in MBP?

 

[mrvo]

Do you have any idea why iMac’s SSD is slower than those in MBP?

T2 chip.

iMac Pro raided SSD w/ T2 controller is the fastest at the moment.

 

[sterretje75]

I just bought a brand new 2019 iMac 5K, 27", 3,7 GHz i5 with 8 GB of RAM and a 512 GB SSD.

Running Blackmagic Disk Speed Test gives an avg. write speed of 688 MB/s and a read speed of about 808 MB/s (see attached screenshot). I would have expected at least a factor 2 faster speeds.

Anyone else experiencing these 'low' speeds?
[doublepost=1558642270][/doublepost]

I just bought a brand new 2019 iMac 5K, 27", 3,7 GHz i5 with 8 GB of RAM and a 512 GB SSD.

Running Blackmagic Disk Speed Test gives an avg. write speed of 688 MB/s and a read speed of about 808 MB/s (see attached screenshot). I would have expected at least a factor 2 faster speeds.

Anyone else experiencing these 'low' speeds?

Oh wow... I just rebooted my iMac and now it reports the speeds I would expect Write of 1875 MB/s and read of 2523 MB/s.

 

[stoker1]

Ok,,, any guesses why my 2019 27 inch 3.6 ghz 128 ram, 2tb ssd, AMD Radeon Pro 48 are giving me , such slow results 1789 write, and 1958 read? I have the odd test that brings up Read to 2050. I have almost every app closed exception of Safari,, and Finder open.
I'm afraid by bringing it into Genius, they might just tell me, after tests, that everything is normal, their automated answer, rather than giving me what they see for a speed. Trying to see what other factors might have the biggest impact, on showing me the truest readings. I'm glad to see this post, because, I have been running Geekbench/or Novabench test and getting rumblings of poor cpu and gpu. Talk about driving me paranoid. After what I spent.. Any thoughts about my read/write experience are welcome. Thanks

 

[mjfutures]

my samsung is 3500/3500 ... makes me wonder if i really want to switch to an imac now haha.

 

[rbart]

In real life, there is absolutely no visible difference between 3000 and 1800 ...
It's only for huge sequencial access, it never happens ...

 

[LGR]

Streaming video one or more streams at once.

 

[Sisti00]

imac 2019 256gb ssd. With mojave it had 2500 Mb/s read speed and 1500Mb/s write speed.

 

[stoker1]

Just curious,, using Black Magicdesign Disk Speed Test,, I observe,, maybe wrongly, that nobody posts what type of drive they are writing to to get their results. Blackmagic, won't let me read/write to my own internal ssd, so I had to choose my external nvme 970 eve samsung as a Target drive to get my results,, Is there a way to find out internally what the Apple SSD is read/writing at?
Still,, going back to my initial post, never did find out why Geek results were so poor and suggesting for me to take look at below average gpu and cpu performance.. And isn't that analysis done on iMac itself, using it's own internal analysis?

 

[hfg]

You might try creating a directory on your internal SSD, such as "test", and then pointing DiskSpeedTest at that directory to run the test. That way you will be sure to have full R/W access.

 

[stoker1]

Thanks,, that definitely did it,, 1709 Write,,2115 Read. Thanks for pointing that out.. Now that I think of it,, first time trying this ages ago,, I might have followed same instruction. Both Read and Write do fluctuate quite a each time I do the test.

 

[Ryo@ryomac]

2019 iMac 3.0GHz i5 with 512GB SSD & 40GB RAM :

 

[stoker1]

Makes me feel so bad now.. and you saw my details,, 2019 iMac, 3.6 ghz, Memory was boosted to 128 gb, i9 ,, Either this iMac doesn't have the specs that were advertised,, or something else is going on. Maybe my Folder the I created to use as a Target has something to do with it? Think I will put in details of my mac in profile. Thanks for posting that Ryo@ryomac,,, even though,,I can see that I am going to have to investigate further, about why such dismal speed Test

 

[Fishrrman]

The differences between those shown in the posts above are pretty much "academic".

You're not going to be able to perceive them "in real life" for most usage situations.

 

[aussiemediaguy]

Would the iMac Pro's SSD be fast enough to video edit on without lag ?

 

[floyal]

I've got a 2019 iMac 5K 27" with 2TB SSD, 3.6 GHz 8-Core Intel Core i9, 32GB RAM

My read is in line with others posts at about 2500 MBs but for some reason, my write speed is abysmal at 390 MBs.

I've got drive encryption turned on (Monterey 12.1), but can't think of any other reason why the speed is so bad regardless.

Anyone has any clue?

 

[Sisti00]

I've got a 2019 iMac 5K 27" with 2TB SSD, 3.6 GHz 8-Core Intel Core i9, 32GB RAM

View attachment 1925339

My read is in line with others posts at about 2500 MBs but for some reason, my write speed is abysmal at 390 MBs.

I've got drive encryption turned on (Monterey 12.1), but can't think of any other reason why the speed is so bad regardless.

Anyone has any clue?

Do a clean install. It have fixed my problems of slow speed