Blackmagic Forum

Hello!

I've been using Blackmagic Speed Test for a while now and have found it really useful.

Uptill now, I was using it successfully on my old 2009 Mac Pro tower, running on Sierra.

However, I now have a new Mac Pro (the Trashcan one), on which I've done a clean install of High Sierra and have downloaded BM ST again.

When I run it now, I get very strange results on all drives I test it on.

Whilst the Write speed looks like it might be reasonable, the Read speed goes completely off the scale, the latest one being 6459.6Mb/s, which seems very unlikely, considering the Read speed is only 167.2Mb/s!

This happens on any drive I test it on, whether it be an SSD in a USB 3.0 enclosure, or an external 3.5" HDD.

The first snapshot I've posted is the results on a USB Key - way off!!

I've tried changing the stress level and everything, but still the same results.

Can anyone advise? I haven't been able to find anything about this issue anywhere!

Many thanks

Matthew

Have you tried deleting the BMD Speed Test and reinstalling the latest version?


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Yes, have deleted and reinstalled from the Mac App Store, which I presume is the latest version?

Matt, the latest version is probably included in the Camera update release 4.9. It may be the same but certainly the copy in 4.9 will be the latest. You can just download the update and ignore everything except the Speed Test.


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My bet is that the RAM is getting used as a write cache giving you false positives.

Good guess, Dan, since those speeds are way too fast for any other storage commercially available.


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Ok, why would that be happening to me though, and seemingly no one else?

It's a clean install of High Sierra, but also happened before I wiped my HD and did the clean install of the OS too...

And how can I prevent it from happening?

I'm using V3.1, by the way.

Thanks everyone.

M

Matt, I can’t get Read over 1.9GB/s on my late 2015 iMac. The version I’m using is 3.1 but it came from BMD not the Mac App Store. Perhaps that’s a clue, but BMD Support would love to tackle this one! Give them a call. They can let an intern prove their worth.


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Matt Burlem wrote:And how can I prevent it from happening?

Unfortunately I don't know enough about mac configurations, to help (windows person), i just not that it does it. Hopefully someone who knows more can help.

Thanks for your responses, guys.

Well, I downloaded Blackmagic Desktop Video, as advised by Chris in tech support, as that contains the latest version of Speed Test, which is V3.1.1 (slightly newer than the Appstore version of 3.1...).

That Camera Update 4.9 didn't seem to contain Speed Test.

Just ran it on a USB 3.0 thumbdrive, and it's still doing its thing of erratically Sky High Read results!

Snapshot below, but over the course of about 2 mins, I got the following results (Write / Read):

3.2 /80.0 Mb/s
4.5 / 96.5
20.8 / 5982.3
20.4 / 650.9
18.2 / 6402.0
20.7 / 6208.4
16.2 / 6205.5
16.3 / 6358.4
20.8 / 962.3
16.3 / 6212.3
20.7 / 1567.7
16.1 / 6081.0
17.4 / 6032.1
20.7 / 948.5
16.3 / 6481.0
18.5 / 6424.9

I've just double-checked those and have made no typos.

Same thing happens on any other drive I test, too.

All very strange - any ideas??

M

UPDATE:

Well, Chris in Tech Support suggested I try the AJA Speedtest app, to see if it happens with that too, or whether it's just Blackmagic..

Well, I tried AJA and low & behold, it does the same thing.. (screenshot attached).

All very strange.

On both AJA and Blackmagic, it does the Write, then pauses for ages before it does the Read test, which then goes off the scale.

Seems it’s to do with my system then. Don’t know what it could be though!

The screenshot attached is for the same USB stick I was using before, but as I say, this happens on any drive I test it on.

So, maybe this issue is just something to do with the newer APFS file system if these Mac Pro's then, or something!?

I'm surprised that I can't find any mention of anyone else having the problem though!

Curious....

Go back to Support. Ask them to forward to the appropriate resource responsible for the Speed Test, then move on, and one day you may be contacted to test a new version.


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Yes, well, it seems to be to do with my system, even though it was a clean install of High Sierra, but it's not the end of the world!

Am moving on emotionally now....

M

Understand it can be frustrating to experience something so strange after all your efforts to isolate the problem. I certainly dislike having loose ends. Hoping BMD has a solution eventually... it may be fine after a future update. Maybe your machine has some secret new technology that inadvertently escaped from the lab.

I’m still waiting for that memory technology I heard a while ago that increases memory speeds by a factor of 1000. Still waiting... That would be like having that sensor from Canon that increases light sensitivity by a factor of 10 stops or some ridiculous value. At least we’ve seen the Canon sensor, but general release and affordability are TBD.


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