Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [hdd]

28 questions
29
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1 answer

How is it possible that HDDs are mechanically so robust?

Hard disk drives (HDDs) rely on a small read-write-head which hover about 70 nm over the platter 1, 2. The physical effect on which this hovering is based seems to be the ground effect 3, so it seems as if there is no electronic closed-loop control…
cakelover
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How can I actively provoke data rot on a storage unit?

For a project, I am looking to deliberately provoke data rot on a storage unit (e.g., a hard drive or a flash drive). I understand that most modern OSes and filesystems as well as hardware have countermeasures in place to prevent data corruption.…
ddkk
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6 answers

Of the two - which is the better archival media - Standard HDD or Flash

There are two totally different "bit rot" mechanisms in place here in the two technologies, so which would be expected to last longer? Which is inherently superior for archival purposes. Will a magnetic domain (GMMR) in a "standard HDD" last…
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How to save electronic equipment from ants?

Today I brought out my external HDD and it was full of red ants. It took me an hour to remove the ants (it seems quite impossible to remove all of them; some are still inside). I always see some ants are coming out of my laptop. My sister's laptop…
sakibmoon
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What is the biggest stable memory overhead for SSDs?

With an HDD, the largest overhead in accessing stable memory (where we measure access time from the moment the instruction passes the MEM stage in the pipeline) is the I/O costs for seeking the right track on the disk. Overall, the contribution to…
VF1
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1 answer

What is the maximum magnetic flux density a HDD can tolerate before data is corrupted?

Does anyone have hard numbers explaining the maximum number of Teslas a hard disk drive can tolerate before data will be corrupted. This forum says "a lot", which isn't super helpful. This one claims you need magnets that only governments have…
Zach Rattner
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1 answer

Why does S.M.A.R.T work the way it does?

According to Wikipedia : S.M.A.R.T. (Self-Monitoring, Analysis and Reporting Technology; often written as SMART) is a monitoring system included in computer hard disk drives (HDDs), solid-state drives (SSDs), and eMMC drives. Its primary function…
KenobiBastila
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Artix-7 SATA implementation using LiteSATA won't initialize

I am trying to run the LiteSATA bench file provided for the Nexys Video (Artix-7 xc7a200t-sbg484-1). The board is new and does not have anything connected to it, and I am building / loading the bitstream to the FPGA with the following over USB…
md-raz
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Salvage Motor From HDD Without Screws

I’ve searched everywhere and can’t seem to find how to salvage this motor from my wd10ears HDD. It seems most other HDDs have screws to take it out, but this one doesn’t. The centre screw is just round so that doesn’t get it out. If someone could…
Coconut
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Why do magnetic disks not have multiple heads per disk?

So it seems to me that when trying to improve performance of a external memory device (HDD), the thing that is increased is RPM. Why not have multiple read/write heads per substrate instead of just increasing the RPM? Is this due to the formatting…
SPQR
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Laptop HDD (100565308 Rev A) BIOS chip swap - chip won't come off?

I'm attempting to remove a BIOS chip from a Seagate Momentus 7200.4 HDD with a 100565308 Rev A chip number. I've followed videos online, but for some reason the BIOS chip will absolutely not come off. I'm worried that I will damage the chip from…
Brandon
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4 answers

Do you need to perform an erase before a write with a HDD?

A simple question, the answer to which is surprisingly difficult to find. Does the internal controller in a HDD have to erase a sector on the hard drive if it already contains information, before it can be overwritten? This is what has to happen in…
genericpurpleturtle
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How to use L293D to spin HDD motor FAST?

Short version: I have a HDD motor I want to spin. I have the L293D chip and after hours of fiddling with code and timing, can only achieve 1200 RPM. How can I get more out of it? Long version: I have wanted to build the HDD pov clock for a long…
Matt
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What determines the maximum rotational speed of a hard disk drive?

Through my background research I understand that the limit on the rotation of a hdd is largely the product of heat and the specs of the physical disk, but I am puzzled by the round numbers advertised for speed. In other words, why do speeds jump…
stereo_future
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What HDD‘s to look out for to source strongest voice coils?

This question is pretty niche, but maybe someone investigated this topic before me and can give advice. I want to source voice coils from HDDs (new or second hand ones). The more torque/force the better. What HDD properties do I need to look out for…
matthias_buehlmann
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