Jim Lux
-----Original Message----- From: Vincent Diepeveen [mailto:d...@xs4all.nl] Sent: Monday, February 11, 2013 4:32 PM To: Lux, Jim (337C) Cc: beowulf@beowulf.org List Subject: Re: [Beowulf] SSD caching for parallel filesystems > > I was responding to your question asking for an example of > something needing high bandwidth and small storage, but that > couldn't be adequately addressed by just buying a ton of > conventional RAM. > > These systems don't have a CPU.. it's just disk drive, FIFO, data > converter. You're speaking here of a very specific NASA type problem. >>> not really.. In reality NASA doesn't do much of this. The defense industry >>> does quite a bit more. I would guess that the number of people building >>> wideband signal simulation/record/playback systems is comparable to the >>> number of people building clusters with SSDs.. they're both niches with >>> probably in the range of 1000 firms at that kind of scale. Maybe half a >>> dozen companies building the systems, the rest just using them. It's like asking why one would design shoes for the guy who manages to jump 10 meters high - and then you show up with an astronaut 10+ years away from now who might jump on the Moon 10 meters high :) > > I suspect digital video recorders are another application.. very > similar kind of usage.. > You stream raw video in at some Gbytes/second and just dump it to > the drive(s). digital motion picture projectors at 4K resolution > are probably another example. Although there, you are looking at > fairly large data sets. > Not at all, you just want petabytes of storage there. >>>> see the example of high resolution digital movie cameras.. no petabytes, >>>> but needing GByte/second kinds of transfer rates >>>> Another example would be digital projection in movie theaters. >>>> Distribution on SSDs might be cheaper than distribution on conventional >>>> hard disks: fewer drives needed to get the rate to supply the projector, >>>> and makes the distribution costs cheaper (shipping costs are less on a >>>> smaller box). They're not looking Petabytes here either. A few 10s of >>>> Terabytes, I would imagine. > The RED cameras stream to flash, SSD or conventional drives, for > instance. 9Megapixels/frame*30 fps is 270 megapixels/second. > The newer EPIC cameras do 31.8Mpix/frame * 96 fps... I think > they run about 400-500 Mbyte/sec to a SSD "magazine" > The film business is used to interchanging magazines. A typical > 35mm cine camera has 400 ft and 1000ft magazines. At the usual > 24fps, that works out to about 1 foot/second, so 400 or 1000 > seconds of shooting time. A comparable RED/EPIC magazine, then, > probably holds half a terabyte or so. > > > http://www.red.com/store/products/redmag-4-pack > Here you go.. a 4 pack of 256GB drives for $9100... This is embedded hardware, again not some HPC type workload. >>> You didn't ask for HPC workload.. you asked for widebandwidth, small >>> storage.. _______________________________________________ Beowulf mailing list, Beowulf@beowulf.org sponsored by Penguin Computing To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
