Imac 27 late 2017 diskspeed

[lbe]

I have an iMac 27 late 2017 with a 2TB SSD OWC Mercury Extreme Pro 6G installed.
The disk was installed by previos owner
I'm only getting approx 500mb/s read and write running blackmagic diskspeed.
isn't that slow?

 

[Sheepish-Lord]

Slow compared to what?

 

[Dimvol]

For those years, this is a normal, average result.
No need to worry.
There is no point in trying to buy faster and more expensive either. It won't be faster.

 

[lbe]

OK. I believed it shoud be four time faster ... I have just installed a thundebolt external disk on the same computer and it runs at 2000mb/s. So it's not possible to get the same speed on an internal drive?

 

[Dimvol]

These are bus limits.
Here is a sad video on the subject.

 

[lbe]

Is it the same speed on never imac 27?
Can I use the faster thunderbolt disk as the main disk?

 

[Dimvol]

So it is possible.
There are difficulties with updating the EFI, they do it only from the internal disk.

 

[Fishrrman]

OP asks:
"Can I use the faster thunderbolt disk as the main disk?"

Yes.
This is your answer.

I suggest you "move everything over" to the thunderbolt drive, and set that to be the boot drive using the "startup disk" preference pane.

If the external SSD is brand-new (nothing on it), the easiest way to do this is by using either CarbonCopyCloner or SuperDuper to "clone" the contents of the internal drive to the external thunderbolt drive.

Both apps are FREE to download and use for 30 days -- this will cost you nothing.

Very VERY easy to do.

Best of luck!

 

[Nguyen Duc Hieu]

OK. I believed it shoud be four time faster ... I have just installed a thundebolt external disk on the same computer and it runs at 2000mb/s. So it's not possible to get the same speed on an internal drive?

1. It's possible. But not on the 2TB SSD OWC Mercury Extreme Pro 6G, which is a SATA disk.
2. You need to open the iMac and install a new nVME blade to a specific slot on the logic board.
3. Which is pointless since you have already got the thunderbolt external nVME.