Acasis SSD works OKish

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mandreessen

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Acasis SSD works OKish

PostFri Dec 06, 2024 7:55 pm

Hi all,
I used a Samsung T7 Shield wirh my BMCC4k but was never able to record 4k 60fps, even with 8:1 compression. 4k 50fps @8:1 works.
Anyway, I decided just for fun to buy a ACASIS 40Gbps M.2 NVMe SSD enclosure and a Samsung 990 pro 4TB. Didn't work well, SSD got too hot. I put some metall between SSD and aluminum enclosure and it stayed cool. But it seemingly draws too much power, recording stopped after a few seconds or minutes. I put an USB-Hub with 5V power supply between camera and SSD and voila 4k, 60fps@3:1 for an hour (I stopped it).
No, it's not rugged :lol: , but hey, it works!
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Ellory Yu

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Re: Acasis SSD works OKish

PostFri Dec 06, 2024 8:56 pm

Interesting but you don’t need a 40gb/s enclosure for a 10gb/s usb-c camera port. The Samsung T7 Shield sequential write speed is not enough to handle anything that’s very high resolution and low compressed data.
URSA Mini Pro 4.6K G2, BMPCC 6K. iMac Pro 27” 5K Retina, 64gb, 1Tb SSD, 12Tb M.2 NVMe TB4 DAS, 36Tb HDD DAS, Vega 56 8gb GPU/ BM Vega 56 8gb eGPU, MacOS Sequoia+DVRS 19.1.4, BM Panel & Speed Editor. Mac Mini M2 Pro 10/16 cores, Sequoia+DVRS 20
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dondidnod

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Re: Acasis SSD works OKish

PostSat Dec 07, 2024 3:07 am

I’d be concerned that you choose a drive that doesn't use too much power. The camera might not supply enough for reliable operation. I noticed that the BM official recommended list for Nvme drives on the optional SSD recorder that runs off the USB-C port of the URSA Mini Pro 12K are the low power ones. The 1TB WD Black SN750 NVMe SSD is recommended.
You can use the speed test software that BM provides on the support page to see if your drives are fast enough.

u/NIGERlAN_PRINCE wrote:

"Decided to see what, if any differences there are in transfer speeds and the ability to shoot at certain quality levels when using a fast SSD vs a cfast card. I recorded for 30 minutes in each test, formatting the card/ssd each time.”

Re: Pocket 6K (Pro + G2) not compatible with USB4 drives

viewtopic.php?f=2&t=197290&p=1027527&hilit=+WD+SN850X+with+Sabrent+#p1027527
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mandreessen

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Re: Acasis SSD works OKish

PostSat Dec 07, 2024 6:01 pm

You are of course right. Anyway, providing power through the USB-Hub eleminates power issues with the bmcc4k.
The shield does not (anymore) provide the data rates neccessary for 4k. I recently tried 4k, 50fps, 5:1 and it stopped recording after an hour. This drive, same cable, is able to record 4k, 60fps, 3:1.
Yes I don't need 40GBit/s for recording, but reading at high data rates when copying to the workstation is nice to have ;-)

I wouldn't recommend using that for production but for me it might work fine. I could easily swap the nvme-drive and have lots of storage relativly cheap.

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