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Comment by gruez | Hacker News Reader

Serious question: why is this considered innovative? 256 GB micro sd cards are widely available[1], and are less than a quarter of the size of sd cards (by area). Surely they can take a 256GB micro sd card's die, copy paste it 4 times, and end up with a 1 TB SD card?

[1] https://www.amazon.com/dp/B01G7L03OS

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I think it's being treated as noteworthy due to reaching a milestone. It doesn't feel very long ago that we hit 1GB.

Edit: after a quick Google search: "Jan 29, 2004 - Sandisk ships world's first production 1GB SD card"

You generally can't just stick separate chunks of flash memory together to make one big one, because the controller is the limiting factor. Having a chip being able to manage large amounts of flash memory (having to have its own memory for the allocation tables, wear leveling, and so forth) is where it gets tricky.

But we've had 1+ TB flash controllers in SSDs for several years, too.

Yes, and they're disproportionately more expensive (ie more than twice the price of 2 500GB's) because of the aforementioned issues. It's also the bottleneck in having say 5TB SSD's that are just 20 smaller ones stuck together, because you could cram them into a 3.5 inch enclosure.

3.5 inch SSDs are expensive because they are primarily used in very expensive servers, and they aim for maximum performance.

If your main concern is capacity, you can easily use multiple controllers. In the laziest case just put a cheap raid controller in front.

Innovation doesn't mean breakthrough.

Also, innovation isn't just having the idea. Innovation is actually doing it.

Well I think the main problem is going to be the power draw. An SD Card has like a 100ma power envelope. The only way to overcome this is to shrink your parts down so that their power consumption comes under that.

Flash reads are power cheap but flash writes are power expensive.

Adding more capacity at the same speed doesn't require more active area or power draw.

Adding capacity to an SD card means either increasing the density of the flash chip or using more flash chips. In this case the op was referring to doing the later strategy. In order for additional dies to not alter the power characteristics of the card, the controller chip would have to have some sort of active power management built in power off dies that aren't in use.

Idle energy use for a typical SD card is well under 1mA. Even though the OP was suggesting something a bit more sophisticated than 4 entire separate cards inside one, it would work just fine.

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