Open Pandora and Sd UHS-I cards

[Askarus]

Does it make sence to buy one of these new Ultra High Hpeed Cards?


Can the Pandora handle speed like 90 MB/s reading speed?


This might be useful for some PanDebian aps.


Here's one of those cards.


http://www.amazon.com/16GB-10TO90MB-TRANS-RATE-UHS-I-SICS/dp/B004X96COW/ref=sr_1_1?ie=UTF8&qid=1331362087&sr=8-1


Price is ok.


If you say it might improve the loading speed of some apps I'll buy one and test it.

 

[laurencevde]

No. The Pandora's max throughput is 25MB/s, and most, if not all, UHS-cards have low random write-speeds, which is caused by them using multiple flash-chips in parallel, thereby raising the minimum i/o-size. The best/fastest card to get is the Sandisk Extreme (also called extreme III, and extreme HD Video), which should cost ±$35,- for a 16GB.


here's a good benchmark: http://www.tomshardware.com/charts/2011-sd-cards/benchmarks,125.html

 

[Askarus]

Thanks. I might buy one of the cards you suggested.

 

[Linux-SWAT]

The Pandora's max throughput is around 16MB/s for ONE slot, and around 25MB/s using both slots in parallel.


The main interest in having a 15MB/s or more SD, is when you transfer data from your PC, using a card reader. I do that A LOT, and i'm happy to have UHS cards.


I recommend the "SanDisk Extreme HD video" 30M/s. The read speed is really near the top, and the write speed is the best i tested. Even the Extreme Pro 45M/s have slower writes on the OP.


I think the biggest ones are 16G cards.

 

[sixtyfifthbit]

I've done the math on the maximum speed for the bus the SD slots are connected to, and I think it ends up maxing out at about Class 6. I don't bother buying faster cards, and I try to target this speed when I buy, because the Pandora is my primary target of these cards. Can anyone support/disprove this assessment? It would be nice to know if I should be targeting a faster or slower speed.

 

[Linux-SWAT]

As i said, if you put many/big files from your PC into a card you will put in your OP, then having a fast card is interesting.


You're probably right with the class 6 limit, but don't forget that SD gets slower with usage.

 

[laurencevde]

@atari_eric: take a look at the benchmarks I posted. Most class6+-cards max out the sd-card's bus-speed in sequential read/write and random read, but there's only one (tested) card with a decent random write-speed, which matters a lot for OS-purposes: the Sandisk Extreme.

 

[Tharf]

Hi all,


I pre-ordered on January 31 and now looking for a fast sdhc card to feed the Pandora with


I looked on amazon.fr for the Sandisk Extreme III / Hd Video, but the references I found seems weird :


Sdhc Extreme Hd Video 16go Class 6 (SDSDX-016G-X46) (21€) : http://www.amazon.fr/gp/product/B0037FLUYU/


Sdhc Extreme III 16go Class 10 (SDSDX3-016G-X46) (36€) : http://www.amazon.fr.../dp/B001ENL5RY/


Sdhc Extreme Hd Video 32go Class 10 (SDSDX-032G-X46) (47€) : http://www.amazon.fr...uct/B004Q3C98S/


If you take a look at the references codes, there is 3 added for the Extreme III (and a few euros !).


So I'm wondering if the "Sdhc Hd Video 32go Class 10" will be almost as fast as the "Sdhc Extreme III 16go Class 10" for OS-purposes (random write speed) ?


Or maybe it's just a change in the card name.


Thanks in advance!

 

[Linux-SWAT]

Maybe it's a rebrand ?

 

[laurencevde]

The extreme III hasn't been in production for quite a while. Sandisk gave it a UHS-1 30MB/s-mode and relabeled them as Extreme, and then, when they introduced the Pro, as Extreme HD Video.


Their performance is practically the same, and I can't find any difference between class-6 and class-10, which even have the same code... I guess the newer ones got labeled with 10...


I guess the only reasons the extreme III's are more expensive is because they're becoming exctinct, it's a well-established name, and that's what the few shops that still have them bought them for...

 

[Tharf]

Thanks ! I think i'll take one Extreme Hd Video 32go Class 10, or maybe 2x 16go Class 6

 

[Linux-SWAT]

I have 8G and 16G version of this one (dunno the 32G version), and they are very good.

 

[Tharf]

Ok, finaly it will be 2x 16go, one for Os and one for apps (at start, a few month later it will be a total mess ), to take full advantage of both slots. I'll be able switch the apps's one with any spare sd if needed.


Anyway, thanks a lot, I was about to take a 16go UHS and I'll have 2x 16go best suited for the Pandora, for a nicer price