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Blackmagic disk speed test issue

PostPosted: Thu Aug 17, 2023 4:27 pm
by javi_garcia_guitar
Hi! New here because I don't know where else to go :')

I don't know if this is in the right category, forgive me if I was mistaken moderators.

I have a Toshiba Canvio Basics 2TB HDD bought few years back. It has two partitions, one of 1.5GB for data formatted as ExFAT and the other 500GB for Time Machine backups formatted as APFS Case-sensitive.

My Mac is a Macbook Pro 15-inch, 2018, 2.2GHz 6-core Intel i7, Radeon Pro 555X 4GB, 16GB RAM 2400 MHz DDR4, running Ventura 13.5.

My issue is that my external HDD seems to have difficulties to be read properly, causing me to not being able to transfer the .photoslibrary of the Time Machine backup to my mac. Here's when comes Blackmagic speed test, that throws me this result:
Screenshot 2023-08-17 at 17.55.31.png
Blackmagic speed test result
Screenshot 2023-08-17 at 17.55.31.png (746.67 KiB) Viewed 8380 times


I've repaired the HDD with Disk Utility, from inside macOS and from Recovery Mode.

First time I tried to copy the whole library (160GB) it showed me that it couldn't complete de copying -being at 90GB- because of a problem on some file inside the library, but after that -as of right now- I'm not being able to copy the individual folders inside the .photoslibrary package, I just can copy the photos inside originals folder in small batches of 100-200MB, because it gets stuck if I try to copy bigger batches of photos.

ANY insight would be really helpful. I don't know if I can perform any other repairs to my external HDD. For sure firs aid of Disk Utility did well because before that it would get stuck at copying just a 10MB photo, so I believe it would be any other utility I don't know of that could get my HDD working well.

Sorry for the long post! Thank you again.

Javi.

Re: Blackmagic disk speed test issue

PostPosted: Sun Aug 20, 2023 10:47 am
by Uli Plank
Sorry for the bad news, but I'm afraid your HDD is about to die.
Try to save everything you can still read and get a new storage. And then, use HFS+ or APFS instead of exFAT.

Re: Blackmagic disk speed test issue

PostPosted: Mon Aug 21, 2023 5:01 am
by Marc Wielage
javi_garcia_guitar wrote:I have a Toshiba Canvio Basics 2TB HDD bought few years back. It has two partitions, one of 1.5GB for data formatted as ExFAT and the other 500GB for Time Machine backups formatted as APFS Case-sensitive.

I'm in shock that anybody would partition a drive and then format part of it one way and part of it another way. I think this is a very bad idea. I also agree with Uli above that exFAT is not good for Macs (in general). AFPS -- as far as I know -- is just for SSDs.

I think you're better off using Mac HFS+ Journaled on a regular spinning drive, and not partition it at all. If you need to read or write it on Windows, have the Windows user get MacDrive and use that.

Re: Blackmagic disk speed test issue

PostPosted: Mon Aug 21, 2023 9:15 am
by Uli Plank
APFS (Apple FileSystem) can be used for HD too from Mojave onward.
But in a way, I silently was thinking of SSDs anyway ;-)

Re: Blackmagic disk speed test issue

PostPosted: Thu Feb 13, 2025 12:17 am
by Scubaman
Hi,
I have a new Mac Pro M2Ultra (Sequoia 15.3.1) with two Samsung U.2 1.9TB SSD's (model PM9A3) installed in a Sonnet Fusion Dual U.2 PCIe card in slot 2.

Using the macOS Blackmagic Disk Speed utility gives the following weird results: 2700MB/s WRITE / 50MB/s READ!

The same test using the ATTO Disk Benchmark Utility gives similar results (WRITE ok / READS poor) for "Transfer sizes" >4MiB

Running the Blackmagic disk speed test on the 2TB Mac Pro internal SSD gives a much more realistic result: 3840MB/s WRITE / 4960MB/s READ

Does anyone have any idea what's going on here? Is the Blackmagic s/w reporting reliably?

Many thanks for any help with this.

Re: Blackmagic disk speed test issue

PostPosted: Thu Feb 13, 2025 1:02 am
by Uli Plank
It works very reliably here, including external storage. Something is very wrong there, maybe the Sonnet enclosure?

Re: Blackmagic disk speed test issue

PostPosted: Thu Feb 13, 2025 10:28 am
by Scubaman
That was my conclusion too ie that the Sonnet PCIe card must be at fault. So I arranged to send it back to Sonnet for evaluation. In the meantime, I bought a cheap single U.2 SSD PCIe card (StarTech) to keep things going. And guess what - exactly the same issue - WRITE ok / READ awful. So I'm not so sure it's the Sonnet dual PCIe card. Maybe it's the Mac Pro or maybe it's the Blackmagic Disk Speed s/w? Hence the post on this forum.

Re: Blackmagic disk speed test issue

PostPosted: Fri Feb 14, 2025 5:17 am
by Uli Plank
Did you try a simple external SSD, connected by USB-C?

Re: Blackmagic disk speed test issue

PostPosted: Sun Feb 16, 2025 7:53 pm
by Scubaman
Yes, that works fine.