SDHC substitute for SxS cards

Nathan Lawrence · September 26th, 2008, 09:40 AM

Steven-

So how reliable do you think this solution is? More reliable than PHU? But perhaps not as reliable as SxS? I know you are still testing, but would the SDHC solution be acceptable for paid-absolutely-can't-lose-my-footage gigs?

--Nathan

Ola Christoffersson · September 26th, 2008, 10:08 AM

I'd say (knocking very very hard on wood) that after one week of trying I'd trust a top quality SD-card more than Sonys harddrive.
I have tried to get my Sandisk SD-card to fail in all manners I could think of without being able to. It can do a whole card of overcrank in 48 fps which suggests a headroom of almost 100%. The only problem I see with the SD-cards is not being able to close the door of my EX1.

But - I must add - testing has only been going on for a little more than a week. I'd wait a few more weeks to be certain that no strange problems arise.

Steven Thomas · September 26th, 2008, 10:40 AM

Well, PLEASE do not go on just my word.

I've been testing the EX1 with:

Kensington 7-in-1 Expresscard reader
16GB SanDisk Extreme III 35MB/s version SDHC (just released)
4GB SanDisk Ultra II 15MB/s SDHC

I've been trying all HQ modes with NO errors at all.

Remember S&Q overcrank mode is not "suggested" with the Kensington/SDHC card combo.
Why do I say suggested, well with the above mentioned SDHC memory cards listed, I've been able to overcrank in S&Q mode to 40FPS at 720 24P wihout an error.

Having said that I DO NOT suggest using S&Q overcranking. At 45FPS ( 720 24P ) it errors.
This is NOT enough headroom for safe overcranking. If you need to overcrank for slo-mo, use your SxS card.

As I mentioned before, the great thing about knowing this combo can overcrank at 40FPS, it shows us the amount of headroom we have over 35mbps (40mbps max) which is the HQ modes.

The data rate maintains HQ mode (35mbps) during playback of any HQ file regardless if it is overcranked (slo-mo when played back at 24FPS). Therefore, the data rate written during S&Q overcrank must be increased proportional to maintain 35mbps during playback.

The HQ data rate maintains 35mbps, but can hit a max of 40mbps. So, if we were to overcrack twice the framerate of 24FPS, we would set the EX1 to 48FPS. To do this we would have to be able to write at twice the HQ data rate 35mbps (40mpbs max) or 70mbps (80mbps max.)

We can only reach an overcrank of 40FPS (720 24P), which equates to 1.6 times the initial 24FPS framerate. SO, since the data rate written in S&Q mode is proportional to the base rate, in this example HQ mode (35mbps) which tops out at 40mbps, 40mbps x 1.6 = 64mbps (max)

You can see why this combo works well knowing that HQ mode tops out at 40mbps and the combo Kensington/SDHC (listed above) is capable of 64mbps max. This seems like a safe amount of headroom for HQ modes and of course even safer for SQ.

Steven Thomas · September 26th, 2008, 10:47 AM

Ola, are you using Sandisk Ultra II, or the new Extreme III?

The Extreme III failed at overcrank of 45, but oddly, I believe the Ultra II ran at 45.

Either way, our numbers are hanging on the edge at this overcrank data rate.

But you're right. I'd say we are safe running HQ modes with this decent headroom.

Based on what I'm reading regarding the Sony drive, it apparently (for some odd reason) may have less headroom, or some other issue.

Again, like yourself I have not been able to get the Kensington/Sandisk SDHC (i've listed) to fail. It works great and spans across both Kensington cards I have inserted in my EX1 with no problems.

I'm looking forward to hearing about or trying the new SanDisk 32GB Ultra II 15MB/s SDHC cards. It's hard to believe I will be able to two 32GB cards (64GB)loaded in the EX1 for under $400!

Alister Chapman · September 26th, 2008, 12:20 PM

Keith, I was surprised by the performance of the Transcend 16Gb cards. I had expected something more like the 8Gb cards, which like you I find work upto 38fps. There may not be different model numbers but I wouldn't be surprised if small improvements creep into production runs. Maybe they are produced in different factories. Who knows? Either way, even the lowly 8Gb cards at 38fps are plenty fast enough for HQ.

Ola Christoffersson · September 26th, 2008, 03:00 PM

Quote:

Originally Posted by Steven Thomas

Ola, are you using Sandisk Ultra II, or the new Extreme III?

I use an 8 GB Extreme III and like I mentioned above it managed to overcrank all the way up to 48 fps in 720p 25 mode. Even considering that you ran @24 fps that is a little bit better and gives even more headroom.

It would be very interesting to hear what the Sony harddrive can handle! Please, anyone with a PHU-60K, would you test it out. What fps can it achieve?!

Ned Soltz · September 26th, 2008, 03:16 PM

The Sony hard drive cannot over/undercrank. This is documented in the product literature.

Steven Thomas · September 26th, 2008, 03:26 PM

Yes, but I seriously doubt it disables overcrank when the EX1 or EX3 is set to overcrank.
The thought is it can overcrank to a certain FPS before it errors.
Is this not the case?

Who has one that can actually try this?

Set the camera to 720 24P, turn ON S&Q, slowly increment from 24FPS, 25FPS, 26FPS, ect... until you determine when it fails.

Ned Soltz · September 26th, 2008, 04:20 PM

Another experiment today...

EX3 with Kensington reader + SanDisk Extreme III 16gb card

S&Q Motion-- No problem shooting 24fps/40. At 45 fps, got media error and had to restore card. Recorded 24/45 to SxS card with no problem, of course.

Then copied the 24/45 clip to the SanDisk card in camera.

Mounted SanDisk card on MacPro via a USB2 reader. The 24/45 clip played back perfectly in the Sony Clip Browser 2.0 s/w reading directly from the card-- not even transferred to an internal drive or a raid. So, the bottleneck is definitely with the EX ability to write rather than the card being able to sustain the read.

Alex Raskin · September 26th, 2008, 05:09 PM

What if you record 24p/60 overcranked on SxS, transfer to Sandisk, and try to play that off Sandisk?

Steven Thomas · September 26th, 2008, 05:36 PM

The HQ playback rate is always 35mbps, even recorded overcranked HQ.

The higher data rate is needed during overcrank recording in order to maintain the HQ 35mbps playback at original frame rate.

Paul Kellett · September 27th, 2008, 03:33 AM

I've got the 8gb sandisk extreme 3 and a few transcend 8gb,no problems so far.
I'm thinking of getting a few of the 16gb transcend, is everybody happy so far with the 16gb transcend ?

Thanks.
Paul.

Paul Kellett · September 27th, 2008, 07:26 AM

Has anybody tried one of the transcend 32gb sxs cards yet ?
I can get them for about £80.
2 of them in the camera shooting in HQ = 8hours, with no card changing to worry about.

Paul.

Matt Davis · September 27th, 2008, 08:20 AM

Quote:

Originally Posted by Paul Kellett

2 of them in the camera shooting in HQ = 8hours, with no card changing to worry about.

4 hours, surely?

Even so, 4x Kensingtons, 4x 32 GB cards < 2x 8 GB SxS and = 1 day conference shoot.

And costs less than the CF card device launched recently.

Conference shoot on 2x EX with no tape ingest = Nirvanah.

Sorry Chris, this calls for a smiley - :-D

Paul Kellett · September 27th, 2008, 08:32 AM

Yes Matt, you're maths is correct, what was i thinking !.
I coud get the same amount of storage using transcend 16gb cards for the same price though.
Less footage to loose though if 1 card goes down for whatever reason.

4X8gb
or
2x16gb
or
1x32gb
or
all the same price but 4x8gb is safer.

Paul.

September 26th, 2008, 12:20 PM	#305
Alister Chapman Inner Circle Join Date: Dec 2005 Location: Bracknell, Berkshire, UK Posts: 4,957	Keith, I was surprised by the performance of the Transcend 16Gb cards. I had expected something more like the 8Gb cards, which like you I find work upto 38fps. There may not be different model numbers but I wouldn't be surprised if small improvements creep into production runs. Maybe they are produced in different factories. Who knows? Either way, even the lowly 8Gb cards at 38fps are plenty fast enough for HQ. __________________ Alister Chapman, Film-Maker/Stormchaser http://www.xdcam-user.com/alisters-blog/ My XDCAM site and blog. http://www.hurricane-rig.com

September 27th, 2008, 03:33 AM	#312
Paul Kellett Trustee Join Date: Nov 2007 Location: Bristol UK Posts: 1,273	I've got the 8gb sandisk extreme 3 and a few transcend 8gb,no problems so far. I'm thinking of getting a few of the 16gb transcend, is everybody happy so far with the 16gb transcend ? Thanks. Paul. __________________ Round 2 GH5,FZ2000

September 27th, 2008, 07:26 AM	#313
Paul Kellett Trustee Join Date: Nov 2007 Location: Bristol UK Posts: 1,273	32gb transcend sxs, anyone tried them ? Has anybody tried one of the transcend 32gb sxs cards yet ? I can get them for about £80. 2 of them in the camera shooting in HQ = 8hours, with no card changing to worry about. Paul. __________________ Round 2 GH5,FZ2000

September 27th, 2008, 08:32 AM	#315
Paul Kellett Trustee Join Date: Nov 2007 Location: Bristol UK Posts: 1,273	Yes Matt, you're maths is correct, what was i thinking !. I coud get the same amount of storage using transcend 16gb cards for the same price though. Less footage to loose though if 1 card goes down for whatever reason. 4X8gb or 2x16gb or 1x32gb or all the same price but 4x8gb is safer. Paul. __________________ Round 2 GH5,FZ2000

September 26th, 2008, 09:40 AM	#301
Nathan Lawrence Regular Crew Join Date: Feb 2008 Location: Cobleskill, NY Posts: 51	Steven- So how reliable do you think this solution is? More reliable than PHU? But perhaps not as reliable as SxS? I know you are still testing, but would the SDHC solution be acceptable for paid-absolutely-can't-lose-my-footage gigs? --Nathan

September 26th, 2008, 10:08 AM	#302
Ola Christoffersson Major Player Join Date: Nov 2007 Location: Stockholm, Sweden Posts: 462	I'd say (knocking very very hard on wood) that after one week of trying I'd trust a top quality SD-card more than Sonys harddrive. I have tried to get my Sandisk SD-card to fail in all manners I could think of without being able to. It can do a whole card of overcrank in 48 fps which suggests a headroom of almost 100%. The only problem I see with the SD-cards is not being able to close the door of my EX1. But - I must add - testing has only been going on for a little more than a week. I'd wait a few more weeks to be certain that no strange problems arise.

September 26th, 2008, 10:40 AM	#303
Steven Thomas Trustee Join Date: Sep 2005 Location: Gilbert, AZ Posts: 1,896	Well, PLEASE do not go on just my word. I've been testing the EX1 with: Kensington 7-in-1 Expresscard reader 16GB SanDisk Extreme III 35MB/s version SDHC (just released) 4GB SanDisk Ultra II 15MB/s SDHC I've been trying all HQ modes with NO errors at all. Remember S&Q overcrank mode is not "suggested" with the Kensington/SDHC card combo. Why do I say suggested, well with the above mentioned SDHC memory cards listed, I've been able to overcrank in S&Q mode to 40FPS at 720 24P wihout an error. Having said that I DO NOT suggest using S&Q overcranking. At 45FPS ( 720 24P ) it errors. This is NOT enough headroom for safe overcranking. If you need to overcrank for slo-mo, use your SxS card. As I mentioned before, the great thing about knowing this combo can overcrank at 40FPS, it shows us the amount of headroom we have over 35mbps (40mbps max) which is the HQ modes. The data rate maintains HQ mode (35mbps) during playback of any HQ file regardless if it is overcranked (slo-mo when played back at 24FPS). Therefore, the data rate written during S&Q overcrank must be increased proportional to maintain 35mbps during playback. The HQ data rate maintains 35mbps, but can hit a max of 40mbps. So, if we were to overcrack twice the framerate of 24FPS, we would set the EX1 to 48FPS. To do this we would have to be able to write at twice the HQ data rate 35mbps (40mpbs max) or 70mbps (80mbps max.) We can only reach an overcrank of 40FPS (720 24P), which equates to 1.6 times the initial 24FPS framerate. SO, since the data rate written in S&Q mode is proportional to the base rate, in this example HQ mode (35mbps) which tops out at 40mbps, 40mbps x 1.6 = 64mbps (max) You can see why this combo works well knowing that HQ mode tops out at 40mbps and the combo Kensington/SDHC (listed above) is capable of 64mbps max. This seems like a safe amount of headroom for HQ modes and of course even safer for SQ.

September 26th, 2008, 10:47 AM	#304
Steven Thomas Trustee Join Date: Sep 2005 Location: Gilbert, AZ Posts: 1,896	Ola, are you using Sandisk Ultra II, or the new Extreme III? The Extreme III failed at overcrank of 45, but oddly, I believe the Ultra II ran at 45. Either way, our numbers are hanging on the edge at this overcrank data rate. But you're right. I'd say we are safe running HQ modes with this decent headroom. Based on what I'm reading regarding the Sony drive, it apparently (for some odd reason) may have less headroom, or some other issue. Again, like yourself I have not been able to get the Kensington/Sandisk SDHC (i've listed) to fail. It works great and spans across both Kensington cards I have inserted in my EX1 with no problems. I'm looking forward to hearing about or trying the new SanDisk 32GB Ultra II 15MB/s SDHC cards. It's hard to believe I will be able to two 32GB cards (64GB)loaded in the EX1 for under $400!

September 26th, 2008, 03:16 PM	#307
Ned Soltz Major Player Join Date: May 2006 Location: Teaneck, NJ Posts: 659	The Sony hard drive cannot over/undercrank. This is documented in the product literature.

September 26th, 2008, 03:26 PM	#308
Steven Thomas Trustee Join Date: Sep 2005 Location: Gilbert, AZ Posts: 1,896	Yes, but I seriously doubt it disables overcrank when the EX1 or EX3 is set to overcrank. The thought is it can overcrank to a certain FPS before it errors. Is this not the case? Who has one that can actually try this? Set the camera to 720 24P, turn ON S&Q, slowly increment from 24FPS, 25FPS, 26FPS, ect... until you determine when it fails.

September 26th, 2008, 04:20 PM	#309
Ned Soltz Major Player Join Date: May 2006 Location: Teaneck, NJ Posts: 659	Another experiment today... EX3 with Kensington reader + SanDisk Extreme III 16gb card S&Q Motion-- No problem shooting 24fps/40. At 45 fps, got media error and had to restore card. Recorded 24/45 to SxS card with no problem, of course. Then copied the 24/45 clip to the SanDisk card in camera. Mounted SanDisk card on MacPro via a USB2 reader. The 24/45 clip played back perfectly in the Sony Clip Browser 2.0 s/w reading directly from the card-- not even transferred to an internal drive or a raid. So, the bottleneck is definitely with the EX ability to write rather than the card being able to sustain the read.

September 26th, 2008, 05:09 PM	#310
Alex Raskin Trustee Join Date: Sep 2003 Posts: 1,435	What if you record 24p/60 overcranked on SxS, transfer to Sandisk, and try to play that off Sandisk?

September 26th, 2008, 05:36 PM	#311
Steven Thomas Trustee Join Date: Sep 2005 Location: Gilbert, AZ Posts: 1,896	The HQ playback rate is always 35mbps, even recorded overcranked HQ. The higher data rate is needed during overcrank recording in order to maintain the HQ 35mbps playback at original frame rate.