C500: Sandisk CFexpress Offload Speed

Liam Hall

Liam Hall

Veteran
What speeds are people getting for offloading their CFexpress cards with the Sandisk card reader? I'm sure I should be getting faster than 40MB/s - albeit I'm transferring to drives simultaneously.
 
Liam Hall said:
What speeds are people getting for offloading their CFexpress cards with the Sandisk card reader? I'm sure I should be getting faster than 40MB/s - albeit I'm transferring to drives simultaneously.
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ha..hmm. I've been importing directly to FCPX so I haven't been really paying attention. Just tested a 7gB file to the internal drive on the MBP. 7 seconds. gulp. To my G-tech T3 Raid (HDD) 9 sec. sheesh.
 
Barry G said:
ha..hmm. I've been importing directly to FCPX so I haven't been really paying attention. Just tested a 7gB file to the internal drive on the MBP. 7 seconds. gulp. To my G-tech T3 Raid (HDD) 9 sec. sheesh.
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A 7GB file won't really stress the system, a card full of takes will. Not sure why mine is so slow...
 
Liam Hall said:
A 7GB file won't really stress the system, a card full of takes will. Not sure why mine is so slow...
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Ha.. ok.. well I’ll drain a card tomorrow and report back. I’ll bet it will be in the same range. No idea why yours would be that slow.. that’s like usb 2.0 speeds.
 
500Mb/s to my raid. Check your cables, usb-c cables are wide ranging and include USB 2.0 cables with no external markings.
 
Re-tested with 313gb dump to my RAID, got 740mb/sec. Don't have enough space to dump that to my internal storage, I'm guessing it would be a good bit faster. As always, transfer speeds are just as dependent on the receiving device, so I'd be looking there first. If I dump to one of my archive drives, I'll bet I'd be getting around what Airwolf is seeing.
 
Unless you’re transferring to a SSD RAID, you won’t achieve the speeds that the cards are capable of. The destination drive and potentially the cable used will be the limiting factor.
 
chris f said:
Unless you’re transferring to a SSD RAID, you won’t achieve the speeds that the cards are capable of. The destination drive and potentially the cable used will be the limiting factor.
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You don't need an SSD RAID to get to the full speed a CFExpress is capable of. A decent single NVMe SSD will be able to outrun the card (they're in the 2500MB/s write range now). Of course, your reader and drive need to probably be Thunderbolt. USB 3.1 is only 10Gbps or 1250MB/s... so by the time you factor in the overhead the card is going to outrun the bus.
 
...or the internal storage on iMac pro, Mac Pro, MBP or other high speed internal storage machines which are capable of 2.6GB/s or more. I doubt we'll see the stated r/w speeds from these cards, but should be close. Certainly faster than cFast. Will clear some space from my internal storage and see what it can do...
 
I dumped 110gB off the card to the internal storage of the iMac Pro and it stayed dead on at 1GB/sec thru the entire write. Maybe a thunderbolt reader would do a little better.
 
rexbron said:
500Mb/s to my raid. Check your cables, usb-c cables are wide ranging and include USB 2.0 cables with no external markings.
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I've tried various cables, all are rated for USB 3.1. I think this is a protocol issue with my MacBook Pro. I'm going to try a USB-C to Thunderbolt 2 adapter when I get home next week.
 
Ben Powell Media said:
I've been getting 40MB/s as well. It's excruciating. I have been seeing a lot of people having issues with their sandisk readers. Mine only reads one of my 4 CFexpress cards without my physically holding the card in the slot tightly.

Sandisk support was no help at all.

I ended up buying this, and am getting 300 - 400 MB/s offloading to my raid drive: https://www.bhphotovideo.com/c/prod..._pgrwcfxana_compactflash_express_usb_3_1.html
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Nearly bought that before I left on this job! Good that you're sorted. I'm pretty sure it's the same problem this guy notices in this stunning video:

https://www.youtube.com/watch?v=_E9YBXlKoGY
 
Barry G said:
I dumped 110gB off the card to the internal storage of the iMac Pro and it stayed dead on at 1GB/sec thru the entire write. Maybe a thunderbolt reader would do a little better.
Click to expand...

That's a bit more like it - a bit faster than my 40MB/s!
 
Update: Sandisk got back to me and were sure it was the cable. I checked seven different cables on two machines. The seventh cable worked. That's the last time I buy cables off Amazon.
 
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