A2 microSD cards are overkill?

[RealCelticGamer]

Have Valve confirmed the Deck supports A2 rated microSD cards? Steam Deck supports UHS-I microSD cards, which are capped at 104 mb/s, plus A2 rated microSD cards need support in the Linux kernel.

With Valve supplying reviewers with A1 rated microSD cards, is that confirmation A2 cards are NOT supported?

[Screenager]

I would even go so far and say A1 is overkill. Games don't write much data. A type cards are more for OS installations for example in a raspberry pi.

[Marlock]

how much better is Read speeed in A1 and A2 compared to UHS-I?

write speed is indeed not much of an issue for games, but on the other hand, any Read speed improvement is worth it (including less obvious metrics like having a better sustained speed after initial burst and when the device heats up, enduring a bigger amount of parallel accesses to small files, etc)

then there is also one place where write speeds might matter... initial loading times for games might include the time needed to precompile shaders, which are then cached to disk... not sure if in real-world cases the write speeds are a real bottleneck on that scenario

[RealCelticGamer]

Originally posted by Marlock:

how much better is Read speeed in A1 and A2 compared to UHS-I?

write speed is indeed not much of an issue for games, but on the other hand, any Read speed improvement is worth it (including less obvious metrics like having a better sustained speed after initial burst and when the device heats up, enduring a bigger amount of parallel accesses to small files, etc)

then there is also one place where write speeds might matter... initial loading times for games might include the time needed to precompile shaders, which are then cached to disk... not sure if in real-world cases the write speeds are a real bottleneck on that scenario

The A1 and A2 ratings don't replace the UHS certification, they simply measure IOPS which is supposed to be a more reliable metric.

What I'm trying to establish is if the Steam Deck actually supports the A2 rating as the Linux kernel needs to have a driver and as of 2019, it didn't.

[drbob]

Originally posted by RealCelticGamer:

What I'm trying to establish is if the Steam Deck actually supports the A2 rating as the Linux kernel needs to have a driver and as of 2019, it didn't.

I think support for A2[www.sdcard.org] (i.e the internal card cache) was added in kernel 5.14, see this phoronix article:

https://www.phoronix.com/scan.php?page=news_item&px=Linux-5.14-SD-Improvements

What kernel does the SteamOS currently use? On release the developer FAQ stated it was 5.13 with plans to switch to 5.15.

If it’s still on 5.13 you may need to wait a bit for full A2 support.

[RealCelticGamer]

Originally posted by drbob:

Originally posted by RealCelticGamer:

What I'm trying to establish is if the Steam Deck actually supports the A2 rating as the Linux kernel needs to have a driver and as of 2019, it didn't.

I think support for A2[www.sdcard.org] (i.e the internal card cache) was added in kernel 5.14, see this phoronix article:

https://www.phoronix.com/scan.php?page=news_item&px=Linux-5.14-SD-Improvements

What kernel does the SteamOS currently use? On release the developer FAQ stated it was 5.13 with plans to switch to 5.15.

If it’s still on 5.13 you may need to wait a bit for full A2 support.

I appreciate the information, thank you!
Now Valve need to update the technical specs to confirm A2 rated microSD cards are supported.

[RealCelticGamer]

I've definitively found out that Steam Deck does not support A2 rated microSD cards (even if it did, few of the cards on sale actually reach their claimed specs).
Do not waste money on A2 rated microSD cards, unless they have price parity with A1 rated microSD cards.

A2 rated microSD cards (and SD cards) are essentially a scam ~ https://www.jeffgeerling.com/blog/2019/raspberry-pi-microsd-follow-sd-association-fools-me-twice

Key takeaway: A2 cards seem to sacrifice some performance when used with hardware which doesn't have A2 Command Queue and Cache functions, versus A1 cards, which offer the same random I/O performance on any device.

[notboxbot]

Originally posted by RealCelticGamer:

I've definitively found out that Steam Deck does not support A2 rated microSD cards

How did you find that out?
Is this a hardware limitation, or a limitation of the current kernel?

[Marlock]

hardware design tradeoffs, by the looks of this bit:

It seems like, for A1 cards, the card has to do all the hard work in its controller to achieve the IOPS benchmarks, whereas on A2 cards, a lot of the heavy lifting would be offloaded to the device or operating system.

[RealCelticGamer]

Originally posted by notboxbot:

Originally posted by RealCelticGamer:

I've definitively found out that Steam Deck does not support A2 rated microSD cards

How did you find that out?
Is this a hardware limitation, or a limitation of the current kernel?

It's a limitation of the current Linux kernel; cache and command queuing for A2 rated SD cards has a pull request and should be in the mainline kernel with 5.14 (https://steamcommunity.com/linkfilter/?url=https://www.phoronix.com/scan.php?page=news_item&px=Linux-5.14-SD-Improvements)

However, based on anecdotal evidence, it's possible Valve added the necessary drivers to the kernel they're using for SteamOS 3.0 (a fork of the Zen kernel iirc).

[Marlock]

I thought the current Linux Kernel used on the Deck's SteamOS 3 would be available in Valve's github at the kernel project, but no such luck... still only SteamOS 2 stuff in there
https://github.com/ValveSoftware/steamos_kernel

[D I A B L O]

Iv not used it yet
But the console has 16gig ram gaming at 800p.....
For about 99.99999% of games... It shouldnt really matter,
U know, depending on how things are, a lot of games can entirely fit into its ram, so while it may take a few seconds loading it in.... U should in theory end up with no loading screens (on older games)...
Lets see...
If it dont work from the get go..it can or may be a thing we get over time..or if u put windows 11 onto it..u can just do it yourself via ramdisc

[Lordblumi]

Well, my Steam Deck won't format my SanDisk Extreme PRO 256 GB microSDXC Speicherkarte + SD-Adapter mit A2-App-Performance bis zu 170MB/Sek., Class 10, U3, V30. After almost the complete time for formating it ends with an error.
I also read in another forum, that the Steam Deck won't support A2 micro SD cards due to the current linux version running on Steam Deck. A2 support for linux will be in a newer linux version. Well I'm not a pro in these things but it's very frustrating when you bought a new fast A2 micro SD for you Steam Deck and you can't use it right now.....
Do you also have this problem? Or can you confirm my statement?

[Sasuchi-sama]

Originally posted by Lordblumi:

Well, my Steam Deck won't format my SanDisk Extreme PRO 256 GB microSDXC Speicherkarte + SD-Adapter mit A2-App-Performance bis zu 170MB/Sek., Class 10, U3, V30. After almost the complete time for formating it ends with an error.
I also read in another forum, that the Steam Deck won't support A2 micro SD cards due to the current linux version running on Steam Deck. A2 support for linux will be in a newer linux version. Well I'm not a pro in these things but it's very frustrating when you bought a new fast A2 micro SD for you Steam Deck and you can't use it right now.....
Do you also have this problem? Or can you confirm my statement?

I use a Sandisk extreme a2. No problems here

[Lordblumi]

Originally posted by Sasuchi-sama:

Originally posted by Lordblumi:

Well, my Steam Deck won't format my SanDisk Extreme PRO 256 GB microSDXC Speicherkarte + SD-Adapter mit A2-App-Performance bis zu 170MB/Sek., Class 10, U3, V30. After almost the complete time for formating it ends with an error.
I also read in another forum, that the Steam Deck won't support A2 micro SD cards due to the current linux version running on Steam Deck. A2 support for linux will be in a newer linux version. Well I'm not a pro in these things but it's very frustrating when you bought a new fast A2 micro SD for you Steam Deck and you can't use it right now.....
Do you also have this problem? Or can you confirm my statement?

I use a Sandisk extreme a2. No problems here

Maybe it is because you use only an A2 extreme and not an Extreme pro !

[Sasuchi-sama]

Originally posted by Lordblumi:

Originally posted by Sasuchi-sama:

I use a Sandisk extreme a2. No problems here

Maybe it is because you use only an A2 extreme and not an Extreme pro !

I want to das its backward compatible. Both are A2.