Hack a Day » harddrive

SSD hard drives tank laptop battery life

Juan Aguilar — Wed, 02 Jul 2008 05:20:00 +0000

Tom’s Hardware has been running some tests to challenge the common assumption that SSD hard drives use power more efficiently than magnetic plate drives. Their results were quite definitive: not only are they not as energy efficient, SSDs actually use more power than conventional hard drives.

What they found is that most plate drives are at peak consumption (up to 4W) when accessing files fragmented across the media, which causes the actuator to move back and forth across the media several times. However, this is almost never sustained for extended periods of time; the actuator usually doesn’t move much when reading unfragmented data, and most plate drives are also capable of going idle when they are not in use.

Most SSDs on the other hand, only have two states: on and off. This means that when they are on, they are always at peak energy consumption. Though this number hovers around 2W for most of the SSDs they tested, over prolonged periods this can mean a great deal more power consumption than is immediately apparent, which can have short and long term effects on the battery life of a laptop. See the Tom’s Hardware article for benchmarks of specific products and more in-depth data.

Data recovery tools

Juan Aguilar — Thu, 12 Jun 2008 00:00:00 +0000

In your zeal to delete your data, you may have accidentally deleted files that you wanted to keep. Lifehacker has posted this handy list of data recovery tools to help you get those files back.

As you may know, whenever you delete a file, the only thing that changes is the file system. The data of the deleted file is still on the hard drive, but the file system sees the space containing the file as “blank” writable space. Data recovery software typically looks into the directory where the file was stored and scans it, finding any files not listed in the file system.

The program you choose for this task will not only be determined by your OS, but also by the specifics of your recovery needs. Do you need to recover a single file? Many files? A whole hard drive? An unbootable drive? A really scratched optical disk? Specialized tools for all of these needs are available, and this article will help you find the right program for yours.

Drive Slagging

Juan Aguilar — Wed, 11 Jun 2008 17:00:00 +0000

Maybe you wiped your iPhone by filling the hard drive with music, or maybe you used a more sophisticated method. In either case, your phone is clean, but the hard drive in your computer is still chock full of evidence of your misdeeds (or just personal emails to your mother). If you fear forensic analysis will expose your wheelings and dealings, then a full format is not enough; you’re going to have to obliterate the plates inside the hard drive.

To that end, [Eecue] posted this worklog of slagging a hard drive. Using a propane powered furnace, he melted most of the drive’s components by placing it in a steel crucible which was lowered into the furnace. After a few minutes everything but the steel casing and a few bits of woven fiberglass from the PCB were melted down completely. You can see the entire process in [Eecue]‘s drive slagging photo album.

With solid state drives becoming popular and their inherent difficulty of assured erasure, physical destruction is looking like a lot more reasonable option. As you readers have stated in the past: it’s certainly a lot more fun.

More hardware music

Eliot — Sun, 08 Jun 2008 00:15:00 +0000

today and tomorrow found a few more projects using computer hardware to create music like our earlier Radiohead post. Above is a rendition of The Imperial March using a 3.5 inch floppy drive. Two more projects are embedded below.

harddisko is a collection of defective hard drives from various manufacturers, repair shops, and institutions. The drives are all wired to separate power circuits. As each one powers up, it runs its own unique sounding self test.

Lastly, is the BeggingBot. Using multiple floppy drives and hard drives it performs music. It then asks for donations via the CD tray.

Obsolete technology band

Sean Percival — Fri, 06 Jun 2008 05:00:00 +0000

Radiohead held a contest for fans to remix the single Nude from their album In Rainbows. Frontman Thom Yorke mentioned on NPR that the contest was essentially a joke, since the Nude track is recorded at 6/8 timing and 63bpm, much slower than traditionally mixed music. The above video from [James Houston] is one of the most creative entries. Using old computer hardware he has recreated the track in a very unique way. He uses a Sinclair ZX Spectrum for the guitar track, a dot matrix printer for the drums, a scanner for bass, and a hard drive array for vocals.

Want to make your own band with obsolete technology? Click through for a few pointers to get you started.

Scanners used to be the hot peripherals of their day; now many are reduced to collecting dust. Revive these relics and put them to good use as instruments.

In the Radiohead video we saw an array of hard drives used as speakers. Afrotechmod created the video above featuring the Star Wars theme. He wired the audio input directly to the coils used to control head and platter motion. Since all hard drives are different it may take a little poking around to get the desired effect.

Dot matrix printers are well known for their iconic sounds. In the above video, [Sue Harding] tells us about her experiences with them and how she plays around with color and character density to create new sounds.

Lastly, we have the Sinclair ZX Spectrum. While it’s not entirely clear what program is being used, there are quite a few audio trackers available for the platform. The video above is a ZX Spectrum demo made by Digital Reality.

[via Waxy]

Breaking disk encryption with RAM dumps

Eliot — Thu, 21 Feb 2008 23:12:00 +0000

If you haven’t gotten a chance yet, do watch the video of this attack. It’s does a good job explaining the problem. Full drive encryption stores the key in RAM while the computer is powered on. The RAM’s stored data doesn’t immediately disappear when powered off, but fades over time. To recover the keys, they powered off the computer and booted from a USB disk that created an image of the RAM. You can read more about the attack here.

How can you reduce this threat? You can turn off USB booting and then put a password on the BIOS to prevent the specific activity shown in the video. Also, you can encrypt your rarely used data in a folder on the disk. They could still decrypt the disk, but they won’t get everything. I don’t think this problem will truly be fixed unless there is a fundamental change in hardware design to erase the RAM and even then it would probably only help computers that are powered off, not suspended.

The potential for this attack has always been talked about and I’m glad to see someone pull it off. I’m hoping to see future research into dumping RAM data using a USB/ExpressCard with DMA access.