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A2-class microSD cards offer no better performance for the Raspberry Pi

jeffgeerling.com

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Re: A2-class microSD cards offer no better performance for the Raspberry Pi

#81

Post by nrp »

djsumdog wrote: post #18

I'm surprised we haven't seen a smaller than M.2 form factor for SATA on embedded devices. It seems like the big limiter on devices like the Raspberry Pi and others are the sd cards/emmc modules, since the amount processing power and ram have been continually going up. If you need disk performance on the Pi 4, wouldn't it make more sense to only keep the kernel,initrd on the sdcard and mount the primary filesystem of…

There's also the UFS Card format, which is a card version of the internal storage that most smartphones use these days. It's still nascent, but in theory should trickle down to single board computers as low cost SoCs get UFS interfaces. It's substantially higher perf than eMMC/SD at read, write, and IOPS.

Re: A2-class microSD cards offer no better performance for the Raspberry Pi

#82

Post by progval »

HankB99 wrote: post #69
jokoon wrote: post #45

How about lifespan? I fail to understand why SD card have such a short lifespan, and it's the sole reason I won't acquire an RPi. It seems that the only think that is lacking on RPi is flash memory storage. Most smartphones have a lot of it, and it seems that 1GB of storage would be enough for the RPi and would not necessarily be so expensive.

> ... and it seems that 1GB of storage would be enough for the RPi and would not necessarily be so expensive. Enough for what? A typical Raspbian install not takes a bit more than 4GB. I don't think that the Lite version (no GUI or applications) would fit either. I'd suggest 8GB, if that's a convenient size. As flash density increases, more and more goes on a single chip and that's where production is going. Consider…

It don't know about Raspbian, but Armbian (headless) fits in 1.2GB

Re: A2-class microSD cards offer no better performance for the Raspberry Pi

#83

Post by nitrogen »

jononor wrote: post #32
djsumdog wrote: post #18

I'm surprised we haven't seen a smaller than M.2 form factor for SATA on embedded devices. It seems like the big limiter on devices like the Raspberry Pi and others are the sd cards/emmc modules, since the amount processing power and ram have been continually going up. If you need disk performance on the Pi 4, wouldn't it make more sense to only keep the kernel,initrd on the sdcard and mount the primary filesystem of…

General practice in embedded is to avoid writing to disk as much as possible. Data collection is mostly done by sending it to the cloud for storage there. However 'edge processing' and 'edge storage' are hot topics, so there will probably be more work in this area. Some of the surveillance camera vendors are showing interest in this, since it would be beneficial to reduce data needed to be sent. Especially since vast…

General practice in embedded is to avoid writing to disk as much as possible.

Yes.

Data collection is mostly done by sending it to the cloud for storage there.

Nononono, what has the world come to?

However 'edge processing' and 'edge storage' are hot topics

Meaning "how it used to be done when hardware was a hundred times slower"?

Re: A2-class microSD cards offer no better performance for the Raspberry Pi

#84

Post by ajford »

deepspace wrote: post #57
gcbw2 wrote: post #46

Earlier quoted context omitted.

smartphone batteries will go out much, much sooner than a RPi SD card write-life. And nowadays they are much harder to replace.

That is just not true. I have burned through many a RPi SD card in 3-6 months, while phone batteries last 2 years at minimum.

What cards are you using?

I have three RPis in abusive conditions, and they haven't had a single SD card issue. Two RPi 3b's running as a car entertainment system, with no form of battery backup/safe shutdown. They are on the ignition power, and once the car turns off, they hard shut down. These have been in place for nearly 2 years with the same Samsung Evo 16GB cards.

The other is attached to a digital signage with less frequent hard shut downs, but still has at least one per week, and been in place since late 2017. Also running a Samsung Evo card (I think it's a 32GB since that's what I had on hand).

Both have high quality power supplies, which may help. The in-car systems have Anker car USB chargers that have been de-cased and soldered in place, while the signage one has an Anker wall charger and a standard micro-b cable.

Re: A2-class microSD cards offer no better performance for the Raspberry Pi

#85

Post by cesarb »

megous wrote: post #41
geerlingguy wrote: post #38

Earlier quoted context omitted.

So is there any kind of device able to use A2 cards at the rated performance yet? I can't get anything better on my Mac with multiple readers (USB 3.0 and 3.1), and I'm guessing if I tried on the reader in my 1 year old Dell XPS, I'd get the same. What good is a performance designation (A2) if no device in the real world supports it?

I don't know. It's a bit of a bummer. I imagine Android would benefit the most (and phones also don't suffer from sudden power outages, which is the biggest risk with enabling this), so someone may try looking if mmc core in androind kernel has patches to support this.

> and phones also don't suffer from sudden power outages

Perhaps you have never dropped your phone, but in my experience, on a dropped phone the battery cover and the battery often go flying.

Re: A2-class microSD cards offer no better performance for the Raspberry Pi

#86

Post by geerlingguy »

cat199 wrote: post #65
geerlingguy wrote: post #38

Earlier quoted context omitted.

So is there any kind of device able to use A2 cards at the rated performance yet? I can't get anything better on my Mac with multiple readers (USB 3.0 and 3.1), and I'm guessing if I tried on the reader in my 1 year old Dell XPS, I'd get the same. What good is a performance designation (A2) if no device in the real world supports it?

> What good is a performance designation (A2) if no device in the real world supports it? this is often the case for new hardware specs/protocols.. see also: any SATA/SCSI rev N+1, TCQ/NCQ, UASP, PCI n+1, etc.

But in all those cases (I have used most of them), there was _some_ way a consumer could acquire hardware (and drivers) to use the tech. It might've been expensive, but I could go out and buy an SATA card, or SCSI 2, or whatever.

With A2, so far I have not seen any way any consumer (or anyone, really) could achieve 2000/4000 IOPS.

That would be like selling a SATA 2400 drive for 2x the cost of an SATA 600 drive... but not selling any kind of controller that could use more than SATA 600 bandwidth.

Re: A2-class microSD cards offer no better performance for the Raspberry Pi

#87

Post by geerlingguy »

blackflame7000 wrote: post #70
vardump wrote: post #66

Earlier quoted context omitted.

FWIW, only noname and Sandisk cards have given up the ghost on me. Samsung Pro & Evo cards have been doing just fine. Other than that, you just need to worry about getting proper power. Just use the official power supplies, and you're fine. Also eMMC chips are no magic. There are crappy ones and good ones. Guess which ones you're going to get for little money?

Proper power is essential. A phone charger is not a power supply even though it works. I suspect a lot of SD cards are getting undeserved blame from a PSU issue.

This is my experience. The only time I had an issue with corruption (using over 60 different microSD cards through 7 years and maybe 50 or so different Raspberry Pis) was when I used a little .5A microSD AC adapter that came with some cheap battery powered device that broke.

I have not had any problems when using a reliable power supply. I'm guessing the 'endurance' or 'industrial' cards some people claim are lifesavers are just doing something to guard against flaky power input when doing reads and writes, so it masks the issue.

Re: A2-class microSD cards offer no better performance for the Raspberry Pi

#88

Post by geerlingguy »

mbreese wrote: post #78
sebazzz wrote: post #72

Earlier quoted context omitted.

What component supports NFS booting? The bootloader is on the SD card, right?

I believe the RPi can boot directly from the network, but it does require a one-time config change that requires booting from the SD card once. After that, the SD card isn’t required for future reboots. (Or actually even supported, IIRC)

I don't think the Pi 4 supports netboot yet[1].

[1] https://www.raspberrypi.org/documentation/hardware/raspberry...

Re: A2-class microSD cards offer no better performance for the Raspberry Pi

#89

Post by mbreese »

geerlingguy wrote: post #88
mbreese wrote: post #78

Earlier quoted context omitted.

I believe the RPi can boot directly from the network, but it does require a one-time config change that requires booting from the SD card once. After that, the SD card isn’t required for future reboots. (Or actually even supported, IIRC)

I don't think the Pi 4 supports netboot yet[1]. [1] https://www.raspberrypi.org/documentation/hardware/raspberry...

I should have mentioned that this was currently only for the 3.

Hopefully that will get fixed soon.

Re: A2-class microSD cards offer no better performance for the Raspberry Pi

#90

Post by pixl97 »

cesarb wrote: post #85
megous wrote: post #41

Earlier quoted context omitted.

I don't know. It's a bit of a bummer. I imagine Android would benefit the most (and phones also don't suffer from sudden power outages, which is the biggest risk with enabling this), so someone may try looking if mmc core in androind kernel has patches to support this.

> and phones also don't suffer from sudden power outages Perhaps you have never dropped your phone, but in my experience, on a dropped phone the battery cover and the battery often go flying.

I will say that at least most flagship phones these days have internal batteries.
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