Why are there 1TB micro SD cards that are the size fingernail and most 1TB hard drives are bigger than my hand?


Why are there 1TB micro SD cards that are the size fingernail and most 1TB hard drives are bigger than my hand?

In: Technology

They are different storage types. MicroSD and other flash storage are loaded on chips whereas inside a hard disk drive there are physical metal platters/”disks” which hold the information. These have also been designed to work across different desktop storage brands with universal mounting capabilities. They are also generally more resilient of a storage medium than flash memory, particularly when it comes to deleted/formatted data recovery. Portable storage has its merits but they are unpredictable at end of life.

A MicroSD card has very limited throughput (read and write speed) compared to a proper disk drive. A really good SD Card can write about 30 MBytes per second. A hard drive can achieve 100MBytes to 200MBytes per second. And a solid state drive can do 500MBytes per second.

So SD Cards are small and cheap, but slow and not robust. Hard disks are cheap, moderately speedy, and robust. SSDs are robust, relatively expensive and very fast.

You must have tiny hands – Modern Solid State drives use the M.2 standard, and are 2cm across, 6cm long and about .4cm thick. And they are that size because that is what the standard is. Companies that want even more compact devices use standards that are smaller still.

SATA SSDs are their size, again, because that is the standard. If yuo were to break open a SATA SSD, you’d find that the circuitry doesn’t take up much of that case.

It is only old school mechanical drives that are about the size of your hand. And these are that size because they spinning platters are abut 7cm across.

Different technologies.

The former uses [flash memory](https://en.wikipedia.org/wiki/Flash_memory) which is implemented with transistors which are really small. The latter uses [physical disks](https://en.wikipedia.org/wiki/Magnetic_storage) which also need some sort of motor to spin them and a reader/writer arm.

On a computer chip, the only thing that matters is the surface layer. The silicon below the surface is just there for support, so the chip doesn’t break apart during or after manufacturing. So what they can do is to grind away the bottom of the chip until there’s just a paper thin surface layer left and glue multiple of these flattened chips into a single stack, which is still thin enough to fit into a micro SD card.

The disadvantage of this is that this doesn’t work with power hungry parts, since concentrating a lot of heat into a tiny area can easily set the thing on fire. But flash memory uses very little power, allowing it to be crammed into tiny spaces like that.

This should not be confused with MLC flash. That means multi level cell, which is a technology that allows to store more than just one bit within each individual cell.

Other than the underlying technical reasons, there’s also a matter of standardisation. Hard drives have to be big enough to fit in a drive bay and have the appropriate connectors.

With solid state hard drives, part of the issue is backwards compatibility. It has to match the size of a magnetic drive to fit security in the case, as well as it has to be large enough for the Sata connector.

Side question, but how much does it cost to produce a MicroSD card? SanDisk’s been dropping the price on their 1TB pretty violently, and it’s got me wondering just how much profit they’ve been able to make per unit.

In SD card technology software on the phone or device acts as the hard disk controller allowing the physical chip to be smaller.

In an SSD hard drives a motherboard which also contains the NAND chips acts as the controller. The SSD NAND hard drive is also a slightly more advanced NAND storage medium (think extra features) requiring a larger die size.

a lot of it is due to technical specification. Where an micro SD basically requires the operating system manage how data is written to it, a hard drive has its own system to handle that.

The other part of it is due to industry standards for sizes.

Hard drives or HDDs are magnetic storage methods that are a few decades old. They are reliable and you can store a lot of data on them. Their size is due to the mechanical components in them and partially due to standardisation. For example, you can find laptop hard drives that are very small. No need to make them smaller as they are quite slow and the machines that use them are servers or desktop computers.

Solid state drives SSDs have no moving parts and they store data in small memory chips. Their size is the same as a laptop hard drive and this is due to standardisation as well. If you open one of these up, you’ll see it’s mostly empty space with a tiny board a few chips in them. There is no need to make them smaller as most devices have bays where these need to fit. Standards again.

M2 drives are the next gen of SSDs. They are faster than SSDs and as robust, but they are smaller than an SSD. They don’t have any casing which saves a lot of space and the new standard allows for a smaller form factor. So thanks to technology, the industry has agreed to make drives a bit smaller for the next gen of SSDs.

MicroSD cards are tiny yes, but this is because the devices that require them are fairly small as well like your mobile phone. Some of the hardware required to make them work is also on your device so that saves space. They are also limited in terms of input/output. Going smaller than this is probably not practical as they are delicate enough to crack or get lost.

In short, storage gets smaller as technology advances but some of the form factors you see are due to industry standards. While I’m sure they could make an SSD the size of your fingernail, it all depends on what devices can support. It usually takes a few years for different manufacturers to agree/adopt new form factors.

Another reason: PC cases already have bays to hold 3.5 inch and 2.5 inch drives. Even if the hard drive itself can be made to work in much less space, it would still be made in one of those form factors to be useable in PC/laptop cases.

The connector alone is bigger than a microSD card

Unless the harddrive is a solid state, it has spinning disks mounted on the inside. If it is a solid state, it will be about the size of a long credit card. That’s why

You can get 1TB or bigger hard drives the size of thumb drives and faster than anything else, they’re generally called NVMe drives. I just ordered a system with three of them.

The magnetic disc drives are bigger because the physical space to store the data needs to be bigger. That said – a lot could probably be smaller but we have standardized the size of a HDD so they fix into a standard drive slot in a computer.

Similarly a SSD is very often mostly empty. If you have an old obsolete one crack it open and take a look – it might be barely more than what looks like an SD drive with a little printed circuit board (PCB) that takes up maybe 10% of the case. Or google “inside SSD case”. The reason for this is the same as above – manufacturers have agreed on a standard size for a SSD case – the case gives manufacturers enough space to make the drives they need to make (some have much more complex PCBs and other supporting infrastructure inside) while ensuring all SSDs are compatible with the standard mounting station in a PC case.

Which brings us back to the SD drive, these can be just the memory chip because all the supporting hardware is inside your camera/computer so it doesn’t need an additional case. The drive is often literally the same size as the actual drive in a SSD (although some SSD drives might have multiple “SD” chips in them to get better storage (ie it might have two 240GB chips) where the SD drive is obviously only one.

I have actually read various Amazon reviews on 1TB SD Cards and most people claim that they either don’t work correctly, have major issues (like data suddenly being deleted), have far less space than advertised,…..etc.

Basically the number of technical issues reported with them in the reviews seemed so high that I am doubtful most of them even work correctly at all. Perhaps some very high end and high quality ones might, but otherwise I have my doubts. I would thus most likely never buy one.

SD cards have only one package of memory limiting performance. Normal size (SSD) drives have multiple packages that give you much better performance: e.g. the SD card will take 8s to weite something, the SSD will only take 1s because it was able to split the write into 8 smaller pieces onto 8 different packages.
Compared to HDDs: SD cards and SSDs have limited number of writes before it dies, HDDs can be written indefinitely because it has magnetic platters that don’t degrade with every write. SD cards and SSDs also have a limited number of reads before the data gets corrupted (known as read disturb), this is more pronounced as the SD card and SSD ages. On SD cards the data needs to be manually refreshed; most SSDs will do this for you automatically; HDDs don’t have this problem.

Lol this isn’t engineering wtf.

Solid state data storage like an SD card and magnetic storage like a hard drive are fundamentally different technology; this is like asking why a VHS Tape needs to be bigger than a Blu-Ray despite the latter having a larger capacity.

The reason they both exist is that they have different characteristics and use cases. An SD card is slow but physically compact, a HDD faster than an SD but far larger and probably cheaper. An SSD is faster than both, smaller than a HDD but bigger than an SD and more expensive than both.

Would you be scared if I told you there were 1TB drives the size of one index finger in length & a little less than two fingers in width?

**And is faster that the drive the size of your hand?**