512 GB CFAST under 100€, 1T under 130€

A promising start. Not bad for 4K 60 fps as well according to the speed test but extensive camera use is the best test. I’d run them until they are full as that might uncover issues that you can see with a 30 second test.

I’d recommend using your most reliable card reader which could be the Wise Advanced Dual Card Reader or an Angelbird card reader.

Record 6K and 4K at increasing frame rates and decreasing codec compression until you see where it breaks.

BMD’s card testing takes several days and is more exhaustive that what I’m suggesting. It’s a lot of work though so you might just begin at the high end if you wish and see where recording no longer fails.

For example start 60 or 50 fps with a complex scene in 6K/4K BRAW Q0 and then 3:1 recording at least three minutes. If those break, try another test with slower frame rate or increased compression like Q1. Do a similar test with ProRes 4:2:2. Once you get success, you could stop testing.

Whatever gives you the highest rates and lowest compression, test that filling an entire card to be sure your results still hold up after the first-level cells are filled. Writing to the second-level cells is more arduous on the card’s data manager the way I understand it.

I agree, likely suitable for photography but not sufficiently robust and reliable for client cinematography. Thanks for bringing that budget media solution to our attention.

Recently I bought a 1 TB Kingspec CFast card for €138,48:
https://aliexpress.com/item/1005004221061527.html

I could record >2 min. of 4K, 60 fps in both 3:1 and Q0 without issue. I also ran CrystalDiskMark, but it seems limited by the speed of my CFast reader.

Recently I bought a 1 TB Kingspec CFast card for €138,48… I could record >2 min. of 4K, 60 fps in both 3:1 and Q0 without issue..

Actual use in camera is a valuable test so that looks like it’s working well with the BMPCC4K.

Have you recorded longer clips until the card is full?

If possible, you might give the Blackmagic Disk Speed app a try. That will also indicate the predicted maximum frames per second at different resolutions.

Recently I bought a 1 TB Kingspec CFast card for €138,48… I could record >2 min. of 4K, 60 fps in both 3:1 and Q0 without issue..

Actual use in camera is a valuable test so that looks like it’s working well with the BMPCC4K.

Have you recorded longer clips until the card is full?

If possible, you might give the Blackmagic Disk Speed app a try. That will also indicate the predicted maximum frames per second at different resolutions.

I haven't recorded longer clips yet, but I might give that a try. It'll take a while to fill up 1TB, though.

Considering the Blackmagic Disk Speed app, I wonder whether it still works when I'm limited by my CFast reader.

Recently I bought a 1 TB Kingspec CFast card for €138,48… I could record >2 min. of 4K, 60 fps in both 3:1 and Q0 without issue..

Actual use in camera is a valuable test so that looks like it’s working well with the BMPCC4K.

Have you recorded longer clips until the card is full?

If possible, you might give the Blackmagic Disk Speed app a try. That will also indicate the predicted maximum frames per second at different resolutions.

I haven't recorded longer clips yet, but I might give that a try. It'll take a while to fill up 1TB, though.

Considering the Blackmagic Disk Speed app, I wonder whether it still works when I'm limited by my CFast reader.

I ran the Disk Speed app, but it's also limited by my card reader, as expected. The data rate at 4K60 BRAW 3:1 in camera (272 MB/s) is always higher than the one indicated by the test.

Thanks for running the BMD speed test which appears to confirm your card reader is slower than your media as you thought. If you want to see if your card still performs well as it fills up, you could stop your test well after it’s half full. The issue is that some drives may struggle when they are recording media with less than 50% capacity remaining.

The BMD chart does indicate your card can record up to 60 fps BRAW (presumably 3:1) and ProRes 422 in 4K. In a very busy scene with lots of edge details, it is possible that BRAW Q0 could fail but in a normal scene it will likely be fine.

Thanks for running the BMD speed test which appears to confirm your card reader is slower than your media as you thought. If you want to see if your card still performs well as it fills up, you could stop your test well after it’s half full. The issue is that some drives may struggle when they are recording media with less than 50% capacity remaining.

The BMD chart does indicate your card can record up to 60 fps BRAW (presumably 3:1) and ProRes 422 in 4K. In a very busy scene with lots of edge details, it is possible that BRAW Q0 could fail but in a normal scene it will likely be fine.

There's an even better deal right now, so I'm considering buying another one. All the more reason to do a thorough test with the one I have using Q0.

That link isn’t saying anything wrong, but it is dated. More current information in much more detail is found in Wikipedia “nand” but the bottom line is that whatever you write on a NAND SSD today will likely experience bit losses in one year at room temperature and much shorter duration at higher temperatures. If you have an SSD that gets extremely hot when you write and read it’s contents, data expires faster.

So the use of today’s typical TLC NAND SSDs throw a lot of hardware design including over-provisioning blocks and sophisticated data management software on the device to prolong the usefulness of the device. This is very true of the leading manufacturers such as Samsung; who knows the genesis of these very cheap SSDs? However they may have a place for tests and personal short term use such as writing media files and offloading within a day to more reliable storage such as a hard disk RAID. I wouldn’t recommend them for regular use on client projects or as devices you use to directly edit your media files.

(Originally posted in the wrong thread)

I think the BMD approved Samsung T7 Shield up to 2 TB is a better budget alternative.

“The 4TB Samsung T7 Shield that once fetched $429 now goes for just $249.”

With prices like that, and the next SanDisk 4TB costing $229, I don’t think the offering mentioned in the OP is worth worrying about.

The Wikipedia article I read recently claimed solid state storage capacity is currently doubling every two years with reductions in power consumed.

After my last post, I did a field test of my Kingspec 1 TB CFast 2.0 card. Initially, I tried to record 4K 60 fps BRAW Q0 for as long as possible. This lasted about 9min45s and finally started dropping frames in a detailed forest setting. This means that the card cannot handle the maximum data rate of around 400 MB/s. I reproduced this frame drop and verified that 3:1 compression gave no issues under the same circumstances.

Next I tried artificially lowering the bit rate of Q0 by lowering the camera fps. I needed to lower to around 45 fps (25% lower max. bit rate) in order to achieve a considerable recording duration without frame drops in the forest. When 45 fps also started to give frame drops, I continued to lower my fps more and more. As the card filled up, I found that I had to go lower and lower. When the card was about 87% full, bit rates at the level of 4K60 BRAW 3:1 started to drop frames as well. Afterwards, performance decreased drastically while filling up the rest of the card.

I decided to make a scatter plot using the metadata of my recordings. The red dots represent frame drops that occurred while filling up the card, and the maximum bit rate that could have led to this frame drop under Q0 (which is 50% greater than the average bit rate of Q0). It's just one session of a few tests, so not statistically representative, but I found it interesting just the same:

Scatter plot of max. bit rates @ frame drop while filling Kingspec 1 TB CFast 2.0

Scatter plot of max. bit rates @ frame drop while filling Kingspec 1 TB CFast 2.0 (1).png (27.34 KiB) Viewed 2563 times

Afterwards, I also ran some disk speed tests on my almost full CFast card (and other media). I noticed that the write speed sometimes drops drastically, while it generally remains at a normal level of ~240 MB/s. The most extreme drop I noticed was to about 30MB/s, but I haven't made a screenshot of that one and couldn't reproduce it since. I wonder whether this is purely card performance, or if it has something to do with my card reader, since these bit rate drops seem worse than what I experienced during my field test.

Disk Speed Test of Kingspec 1TB with 124 GB free

DiskSpeedTest_Kingspec1TB_124 GB free_2.png (201.96 KiB) Viewed 2965 times

Anyways, my tests are still inconclusive as I need more data and experience in the field for that. My CFast card still seems more than sufficient for practical use, especially if I don't use extreme settings or clean up my card when I do decide to use them.

Thanks for the detailed feedback, Frank. Perhaps safe up to 30 fps but not always suitable for 50/60 fps.

After my last post, I did a field test of my Kingspec 1 TB CFast 2.0 card. Initially, I tried to record 4K 60 fps BRAW Q0 for as long as possible. This lasted about 9min45s and finally started dropping frames in a detailed forest setting. This means that the card cannot handle the maximum data rate of around 400 MB/s. I reproduced this frame drop and verified that 3:1 compression gave no issues under the same circumstances.

Next I tried artificially lowering the bit rate of Q0 by lowering the camera fps. I needed to lower to around 45 fps (25% lower max. bit rate) in order to achieve a considerable recording duration without frame drops in the forest. When 45 fps also started to give frame drops, I continued to lower my fps more and more. As the card filled up, I found that I had to go lower and lower. When the card was about 87% full, bit rates at the level of 4K60 BRAW 3:1 started to drop frames as well. Afterwards, performance decreased drastically while filling up the rest of the card.

I decided to make a scatter plot using the metadata of my recordings. The red dots represent frame drops that occurred while filling up the card, and the maximum bit rate that could have led to this frame drop under Q0 (which is 50% greater than the average bit rate of Q0). It's just one session of a few tests, so not statistically representative, but I found it interesting just the same:

Scatter plot of max. bit rates @ frame drop while filling Kingspec 1 TB CFast 2.0 (1).png

Afterwards, I also ran some disk speed tests on my almost full CFast card (and other media). I noticed that the write speed sometimes drops drastically, while it generally remains at a normal level of ~240 MB/s. The most extreme drop I noticed was to about 30MB/s, but I haven't made a screenshot of that one and couldn't reproduce it since. I wonder whether this is purely card performance, or if it has something to do with my card reader, since these bit rate drops seem worse than what I experienced during my field test.

DiskSpeedTest_Kingspec1TB_124 GB free_2.png

Anyways, my tests are still inconclusive as I need more data and experience in the field for that. My CFast card still seems more than sufficient for practical use, especially if I don't use extreme settings or clean up my card when I do decide to use them.

Can I ask you this I have the 1TB of the KingSpec Cfast card... I can't even play back anything off the card it shudders and lags a lot.. Is this how Cfast cards operate? even my SD slot and not even my Samsung T7 does anything like this.. I can't find anything else on it so.