View Full Version : Is this fast enough?Raw port speed required?
04-21-2007, 06:37 AM
Anyone know what is the speed a raid may need to record from the uncompressed port?
Our current raid..
04-21-2007, 06:41 AM
Unfortunately, the Blackmagic disk test is worthless and horribly inaccurate. It often tends to over-estimate the true sustained speed of a drive system.
That aside, you're only about half way there if you intend to use all available modes of the camera via the uncompressed RAW port. Think 1GB/sec, minimum throughput across the entire volume of your array.
04-21-2007, 06:44 AM
Aja estimated 425MBs.
Any suggestions for what is accurate?
I suspect if a job requires 4k D2D then it'll have a decent budget ;)
04-21-2007, 06:55 AM
I do believe the AJA profiling is more accurate, but I don't have enough experience there to know for sure. You will have a tough time reaching the full 1GB+/sec bandwidth using the OSX software RAID system. It's been shown to crap out as more drives and host interfaces are added to the mix.
You will definitely want a hardware RAID solution. External RAID connected via 10GE / Myrai-Net or 2 x quad-link Infiniband (or single 12X) will pull it off provided you have an array of drives that can actually handle the rate. As drive arrays grow, especially in configs of RAID-5, 6 or 7 type where much of the data is used for CRC, parity and other fault-tolerance, the gains are not linear.
There's been a lot of references to "refrigerator RAID" regarding uncompressed capture. That's not too far off... Think mini-frige size and super-expensive connectivity. We also don't have all the details on workflow yet. We don't know if the RED will attach directly to a RAID or if it will need a system capable of ingesting the data stream and then that system writes it to the RAID.
Any way you slice it, it ain't going to be cheap.
04-21-2007, 07:17 AM
Depends on what you want.
The max bandwidths for Raw uncompressed port are:
4.5K x 60 fps (RAW) - 985MB /sec
4K x 60 fps (RAW) - 810MB /sec
2K x 120 fps (RAW) - 405MB /sec
Drop the frame rates and the bandwidths drop proportionally.
04-21-2007, 10:05 AM
current raid (from above grab) is Raid5, dual infiniband.
raw 2k is good for now..
plus really only need 24fps...
04-21-2007, 10:45 AM
Unless you already have s16 glass that you will be using or unless you have specific needs for only shooting in 2K, you're kinda cutting yourself short. 4K REDCODE RAW should be far superior to even 2K uncompressed RAW. After all, there's 4X the resolution / detail, larger FOV, hence shallower DOF available... Just my thoughts.
04-21-2007, 10:51 AM
only concern is for greenscreen really. I see your point. But would like to test redcode on GS stuff..
Good point though..
04-21-2007, 11:04 AM
Something tells me I can pull a better, more detailed key from GS footage shot in 4K REDCODE RAW than 2K uncompressed RAW. But that could just be me... Either way, greenscreen work on the RED is going to be like a dream compared to pulling keys on HDV and DVCPROHD.
I guess we'll find out in due time. I know I won't be buying the RAW port initially unless the workflow is ironed out and looks to be worth-while in time for my camera to ship. The 18-50 zoom is a far better place for my $6500 at the moment. :)
But I'm still interested in the RAW port as I'll be doing some greenscreen work here and would also have a use for 2K up to 120fps.
04-24-2007, 05:31 AM
I'm getting the RAW port even if the workflow isn't ironed out before my camera ships. I just hope RED doesn't leave it up to third-party manufacturers like Codex to make a compatible solution. If RED makes the RED-RAID I would be happy to spend between $10-30k, especially if I could also use it as a high-performance online storage/playback system. Codex would probably charge like $100k +. I hope I don't get stuck with a $6500 port that I can't use!
04-24-2007, 09:01 PM
I plan on adding the RAW Port too...hopefully we can get details soon on a raid solution
04-24-2007, 11:55 PM
Heavily compressed 4k MB for MB is cleaner than uncompressed 2k any day.
I'll roll out my little diagram... again :)
4k Wavelet | 2k Wavelet | HD uncompressed | HD Wavelet
One of these things is not like the other... one of things... doesn't belong... if you can *eherem* err I mean feel free to test it out yourself with some Dalsa footage.