BlackMagic Disk Speed Test Results for HDDs

Sharky II

macrumors 6502a
Original poster
Jan 6, 2004
583
21
United Kingdom
Hi,

I have a 256GB PCIe SSD for a boot drive, and it's great. My main data drive (mainly audio, but also some photos and video) is a 2TB WD Black though, around 70% full. I bought it 4+ years ago.

In the BlackMagic disk speed test I'm only getting around 100MB/sec read/write speeds, about the same as my Samsung F3 1TB from back in 2010.

Isn't that a bit slow, or is it to be expected?

If the drive is just old and slower than modern HD drives (perhaps the model is updated despite still being called a WD Black 2TB)... if I purchase a more modern WD Black, what kind of speeds could I expect?

I guess I'm asking - what speeds are you getting for traditional HDDs in a 4,1/5,1 Mac Pro with SATAII?

Cheers!

Ed
 
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Floris

macrumors 68020
Sep 7, 2007
2,381
1,451
Netherlands
PCIe means it's internal inside the system, and not external on usb?

These are my speeds of my old 7200rpm HDD external disks on usb3 and usb2 cables into the new iMac on usb3.

Since I took this test, and wrote the data down. I got a usbc->sata3 adapter cable for the usb-c port and the SSD went from 265 write & 400 read to 266 write & 500 read (maxing out the disk).

It depends on what the max is for that drive, which connection it's actually on, on both sides, and what speeds the cables, connections, etc are, and what the hardware can support at all.
read write speeds harddrives.png
 

Sharky II

macrumors 6502a
Original poster
Jan 6, 2004
583
21
United Kingdom
Hi,

Thanks! I just meant that I have an M2 AHCI blade for my OS, but that's not really relevant really!

I wanted to know about the speed of people's internal 7200RPM HDDs in 5,1 Mac Pro's connected natively the internal SATA II sled bays. As we're in the Mac Pro forum I thought it was clear but re-reading my post, I can see that it might be a bit ambiguous.

Cheers!

Ed
 

flehman

macrumors 6502
Feb 21, 2015
349
188
Hi,

Thanks! I just meant that I have an M2 AHCI blade for my OS, but that's not really relevant really!

I wanted to know about the speed of people's internal 7200RPM HDDs in 5,1 Mac Pro's connected natively the internal SATA II sled bays. As we're in the Mac Pro forum I thought it was clear but re-reading my post, I can see that it might be a bit ambiguous.

Cheers!

Ed
I had all 4 stock drive bays filled with non-SSDs back in 2015 and they were scoring around 150 read/write in BlackMagic. I can't remember if they were 5400 or 7200, they might have been mix. I now use all SSDs and they score 250-270 read/write in the stock drive bays.
 

LAHegarty

macrumors regular
Aug 17, 2013
112
31
York, UK.
Not sure if my drives are 7,200 but I'm getting around 60 R/W.

Floris How have you made that blackmagic disk test list?
 
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goslowjoe

Suspended
Dec 22, 2017
125
88
I don't want to hijack the OP's thread, but to avoid another thread about the Black Magic Speed Test thought I'd ask here.

Has anyone experienced inconsistencies in the Write/Read results? This is happening to me where a variety of SSDs, even proprietary Apple units in my iMacs and MacBook Pros, give wildly inconsistent results. For example, a brand new Crucial MX500 500GB unit one minute will be 400/400 and more, and a few minutes later it drops to below 150/150. I even had a SSD this afternoon showing a dismal 50/50 where otherwise it is above 300/300.
 

h9826790

macrumors G5
Apr 3, 2014
12,777
5,586
Hong Kong
I don't want to hijack the OP's thread, but to avoid another thread about the Black Magic Speed Test thought I'd ask here.

Has anyone experienced inconsistencies in the Write/Read results? This is happening to me where a variety of SSDs, even proprietary Apple units in my iMacs and MacBook Pros, give wildly inconsistent results. For example, a brand new Crucial MX500 500GB unit one minute will be 400/400 and more, and a few minutes later it drops to below 150/150. I even had a SSD this afternoon showing a dismal 50/50 where otherwise it is above 300/300.
If only write speed is slow, then it should be TRIM related.

But from your description, that seems to be something else.

In my own test, the result always very consistent.

However, I won't be too surprise the speed drops a lot if your system is running out of cache. Or if something else is accessing the SSD at the same time (e.g. the OS is doing some housekeeping job in the background). I rarely benchmark my boot drive. But for iMac / MPB, I bet you were benchmarking your boot drive.
 

goslowjoe

Suspended
Dec 22, 2017
125
88
If only write speed is slow, then it should be TRIM related.

But from your description, that seems to be something else.

In my own test, the result always very consistent.

However, I won't be too surprise the speed drops a lot if your system is running out of cache. Or if something else is accessing the SSD at the same time (e.g. the OS is doing some housekeeping job in the background). I rarely benchmark my boot drive. But for iMac / MPB, I bet you were benchmarking your boot drive.
I did not mention that many of the tests are for external drives, like the Crucial, and the particular SSD is brand new and empty. So this really boggles me. System drives I can understand may be subjected to varying loads.
 

h9826790

macrumors G5
Apr 3, 2014
12,777
5,586
Hong Kong
I did not mention that many of the tests are for external drives, like the Crucial, and the particular SSD is brand new and empty. So this really boggles me. System drives I can understand may be subjected to varying loads.
Then how you connect them?

May be the enclosure itself introduce some bottleneck?
 

grey17

macrumors newbie
Feb 11, 2010
12
0
Central California
With spinning disks the outer most tracks can be 50-100% faster than the inner tracks. So an empty disk will be faster than one that is full. 100MB/s sounds reasonable for 70% full WD black.

FWIW: Current disks in my MP4.1-->5.1 range from 80MB/s to 150MB/s.

-- D
 

splifingate

macrumors 6502
Nov 27, 2013
370
67
ATL
Hi,

[...]

I guess I'm asking - what speeds are you getting for traditional HDDs in a 4,1/5,1 Mac Pro with SATAII?

Cheers!

Ed
I get around 107MiBs Write, and 110MiB/s Read on my 4TB spinners over the internal SATAII ports . . .

. . . an SSD over USB 3.1 gives me roughly 4-5x that, and my AHCI over PCIe-4x gives me roughly 730MiB/s Write, with 1300+MiB/s Read ;)

Regards, splifingate
 

AidenShaw

macrumors P6
Feb 8, 2003
18,085
4,145
The Peninsula
Isn't that a bit slow, or is it to be expected?
With spinning disks the outer most tracks can be 50-100% faster than the inner tracks. So an empty disk will be faster than one that is full. 100MB/s sounds reasonable for 70% full WD black.
I just picked up four 10 TB Seagate Helium enterprise drives for my home media server. ($305 https://www.neweggbusiness.com/product/productlist.aspx?Submit=ENE&DEPA=0&Order=BESTMATCH&N=-1&isNodeId=1&Description=st10000nm0016)

These read/write at 250MB/sec at the outer tracks (beginning of drive), and about 150MB/sec on the inner tracks (end of drive). (SATA 6 Gbps, but 3 Gbps could do those speeds )

Note also that a drive that's been in use and is pretty full might have fragmentation issues, so in addition to the inner track slowdown, there could be extra head movement to access fragments of the test file. This could be especially significant if the drive was ever (even nearly) filled.
[doublepost=1553640865][/doublepost]
These read/write at 250MB/sec at the outer tracks (beginning of drive), and about 150MB/sec on the inner tracks (end of drive). (SATA 6 Gbps, but 3 Gbps could do those speeds )
Also note that the disparity between outer track and inner track speeds leads to a practice often called "short-stroking". Companies would buy much larger disks than they need, and then partition them so that they're only using the faster outer tracks.

Buy a 12 TB drive, and put a 2 TB partition on it. The performance delta between beginning and end of the 2 TB partition becomes minor.

I would guess, however, that the price reductions for SSDs makes short-stroking less common today. (There would be no reason or benefit to "short-stroke" an SSD - although it might be done for over-provisioning. Howerver, leaving unused space on an SSD is called over-provisioning, not short-stroking, since no head movement is involved on an SSD.)
 
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Floris

macrumors 68020
Sep 7, 2007
2,381
1,451
Netherlands
I don't want to hijack the OP's thread, but to avoid another thread about the Black Magic Speed Test thought I'd ask here.

Has anyone experienced inconsistencies in the Write/Read results? This is happening to me where a variety of SSDs, even proprietary Apple units in my iMacs and MacBook Pros, give wildly inconsistent results. For example, a brand new Crucial MX500 500GB unit one minute will be 400/400 and more, and a few minutes later it drops to below 150/150. I even had a SSD this afternoon showing a dismal 50/50 where otherwise it is above 300/300.
I got a 2tb mx500 from crucial that i put on USB-C port, with a cable to sata3 adapter: i am getting pretty cons. speeds to be honest, around 400 read/write. Which I am perfectly fine with for external drives.


The video has a link in the descr to the previous crucial ssd i bought of 525gb that i put on usb-3 with an alike startech adapter and speeds were a bit higher, but after some usage (say a year) the speeds are also around 400 read/write.