Sdhc Cards, Which One For Maximum Performance?

[CasperN]

Didn't find it in the wiki or at the forum.

If I want maximum performance from the Pandora, should I then buy 2 cards like this?

From what I understand they are the most expensive, fastest and biggest in filespace on the market today.

Lets say someone is making an ûber performance application for the pandora, a game for exemple. Will it be able to read from 2 cards at the same time and then get an maximum reading speed of 60 MB/s?
Or will it be a bottleneck? is the 30MB/s cards to any use for the pandora? and are two of them to any use? Will it make things possible that where not possible with slower SDHC cards?
For exemple heavy texture streaming in games? Will it speed up loading times at quake 3 maps?
Will the pandora boot faster with the extreme 3 cards? Can we easy set up the kernel to use 2 cards for the booting and then speed up things a little bit?

Is there any way we can get some kind of benchmarks on the performance before the pandora is shipped?
Or pls give me a link or something with info about pandoras card readers.

A good test to read: 13 SDHC Memory Cards Reviewed
Note that in the test, their cardreader was the bottleneck at 20mb/s read speed,
and also that the sandisk card in the test is the old card at 20mb/s not the new one at 30mb/s.

Hope I didn't miss any tread on the forum about this.
And this tread is not about any SDXC cards from the future. Keep the tread to SDHC cards please.

 

[mali]

There was a thread not long ago, where bandwith was discussed(MWeston responded). You might want to search for that thread first

 

[CasperN]

Ok that was stupid by me, did a n00b search first and only ended up with wiz stuff. Found this now. http://www.gp32x.de...bandwith%20sdhc
But no real statment about how fast it reads from 2 cards at the same time.
Maybe something for the wiki to fill out with?

 

[WizardStan]

Ok that was stupid by me, did a n00b search first and only ended up with wiz stuff. Found this now. http://www.gp32x.de...bandwith%20sdhc
But no real statment about how fast it reads from 2 cards at the same time.
Maybe something for the wiki to fill out with?

Because it hasn't been confirmed whether the SD slots go through a single bus or if they each individually have their own buses. The bus speed is about 24 M/s though.
And as has been mentioned many times before, think about what you want to do with that speed before spending money on it. I've said this many times before so I'll say it again, MP3s are measured in the 100K/s, videos at around 1 or 2 M/s. On a 2M/s card an SNES ROM could be loaded in about a second, N64 ROM under 5 seconds. The entirety of Quake can be loaded into memory in about 10 seconds on the slowest SDHC cards, so I can't honestly fathom how card speed would even begin to be a major bottleneck loading the maps. Slow cards may add a second or two of start up time to some applications, but that becomes less noticeable very quickly just by going up to 4 or 6 M/s.
Yes, it will probably speed up boot time, but even if it halves the time, that's about 40 seconds now (and going to get better) of something that should almost never happen. Do you really want to spend that much money to save 40 seconds every few months or so?
Do this: buy a cheap class 4 card with a few gigs and try that on your Pandora, and only after you've had some real experience should you consider if you need the extra speed. Seriously, 4GB class 4/6 cards can be bought for about $10 (or less, if you know where to look) right now. Better to waste $10 and discover you need more power than $100 to find out you don't, I say. (Not like that $10 card would be a waste, I'm sure you could find some use for it)

 

[CasperN]

Thanks for the answer, will stick with my camera card, 16gb ultra 2 and test first then. I can film full HD with that card, so maybe thats more speed then I ever will need on the pandora. But sure I want to squeeze out as mush as I can.
Anyways, good to know that the 30MB/s cards isn't necessary.

 

[Paradox]

I have 2x 32Gb SanDisk Ultra II's (15mb/s) should be fine for anything really.

 

[strider_mt2k]

I'll be using a couple of Class 6 16GB Micro SD cards in adapters.

What's neat is that they currently reside in two devices that will likely be replaced by my Pandora. (My Pandora -I like saying that. )

I don't honestly know if Pandora will read/write to their max ability, but given the versatility of these memory cards it seemed keeping the Class rating high is a safe bet for any future use as well. (Hey, prices hit the right mark and these will be replaced with larger ones.)

 

[Loonie]

Companies really need to stop putting things like "Extreme" on their products. It just looks pathetic a couple of years down the line; there you are with an ISA bus 512kB VGA card with "APOCALYPSE SLAUGHTIFIER KILLDIE MILLENNISPLOSION 2000" written on it.

SanDisk did at least redeem themselves here by not leaving the "E" off of the beginning of "extreme".

 

[Grench]

Several threads about this...
http://www.gp32x.de/board/index.php?/topic/50499-sdhc-how-fast-is-fast-enough/page__st__30


and there was another one about raid 0, but the general agreement on that is it's pointless.

Bottom line, until someone gets a Pandora and puts a few high $$$ cards in it and times a file copy from one card to the other, nobody's going to know for sure where the line of diminishing returns is.

 

[Pleng]

SanDisk did at least redeem themselves here by not leaving the "E" off of the beginning of "extreme".

Yep. Which is more than the SD Association managed when they came up with SDXC!

 

[peca]

Because it hasn't been confirmed whether the SD slots go through a single bus or if they each individually have their own buses. The bus speed is about 24 M/s though.

They are all on one bus. I was look at OMPA3 TRM and found that they sits on L4 BUS. What I not sure about is bus speed. I remember that someone said 24 MBps but I'm not sure who and where. According to my research the transfer speed is 2 times clock speed which I don't know.
EDIT: I think that that speed 24 MBps was theoretical maximum transfer speed of one card slot. More likely max is about 20 MBps.

 

[Nintendo]

Go with the ADATA brand. Very reliable.
Love 'em!!! andora2ut4:

http://www.gp32x.de/board/index.php?/topic/51342-sd-card-wich-brand-and-size/page__pid__797427__st__15&#entry797427

 

[WizardStan]

Because it hasn't been confirmed whether the SD slots go through a single bus or if they each individually have their own buses. The bus speed is about 24 M/s though.

They are all on one bus. I was look at OMPA3 TRM and found that they sits on L4 BUS. What I not sure about is bus speed. I remember that someone said 24 MBps but I'm not sure who and where. According to my research the transfer speed is 2 times clock speed which I don't know.
EDIT: I think that that speed 24 MBps was theoretical maximum transfer speed of one card slot. More likely max is about 20 MBps.

24 MB/s theoretical, according to MWeston

 

[peca]

24 MB/s theoretical, according to MWeston

Yes, this is it! Though I think that this speed is per card (without guarantee B) ).

 

[zevdawg]

One thing you have to remember is that Cl-10 cards are rated for a minimum 10MB/s (in that, this card is still C10). Class speeds are rated for the devices minimum constant transfer speeds. Slapping 30MB/s on the label is a marketing thing (that and a statement that their cards *can* run up to a certain speed). I'm saying this because a majority of people are writing as though the card's going to hold a constant 30MB/s in the device, when it isn't.

I have a 4GB C6 card for my DS (running from a flashcart), and while it's fast to transfer from card/computer - on the device itself the speed never makes a difference (I have a regular off-the-shelf 2GB Class 1 card in comparison, no difference in speed on the device whatsoever). Someone had to test some cards to find out whether or not speed mattered for the card/device.

I have a feeling that some people will be crazy enough to splurge a large amount on an expensive Sandisk C10 card, only to find that (for example) after C6 cards (Class 7,8,etc.) there is no difference in speed.

Do test if you already have said card, otherwise don't invest in such an expensive card that hasn't been tested with it yet (but I guess some people have more money than sense eh?).

 

[Tensuke]

Also keep in mind that the class rating only concerns the minimum write speed, it may read slower or faster than the class rating.

 

[dflemstr]

[...] it may read slower [...] than the class rating.

I've never seen that myself... Writing to flash is much slower than reading to flash, so the manufacturers would really have to be stupid to build a chip that behaves like you meta-described.

 

[gruso]

The Pandorian’s guide to SD cards

I didn't post this initially because it doesn't answer the OP's question. It's worth throwing in now though.