Root Class 10 SD Card = 1.5Mbps?

[Vastlee]

I purchased a Class 10 card in hopes of getting faster write speeds via usb from PC. They haven't changed. Still topping out at 1.5. When I run a R/W test on the phone I get Write Speed of 8.56MB/s & Read of 9.7MB/s.

This would indicate that the card is capable, but for some reason the connection to the PC is slow. I've tried multiple cables & made sure the USB ports were USB2 (Even tried a USB3 one). Still stuck at 1.5MB/s

Any suggestions?

 

[BlueBiker]

1.5MB/s is the limit of USB1, so either your PC or your card reader are not operating in USB2 "Hi-Speed" mode. My first guess would be the card reader -- can you try a different one? Otherwise see if your Windows has the right drivers loaded for your USB ports in Device Manager.

PS: Your Class 10 card is guaranteed by the manufacturer to be writeable at 10MB/s or higher. If you're seeing less than that on the phone, then either the phone can't quite keep up or the card isn't as good as advertised.

 

[Vastlee]

1.5MB/s is the limit of USB1, so either your PC or your card reader are not operating in USB2 "Hi-Speed" mode. My first guess would be the card reader -- can you try a different one? Otherwise see if your Windows has the right drivers loaded for your USB ports in Device Manager.

PS: Your Class 10 card is guaranteed by the manufacturer to be writeable at 10MB/s or higher. If you're seeing less than that on the phone, then either the phone can't quite keep up or the card isn't as good as advertised.

The cable I'm using is supposedly USB 2. The direct description from Monoprice:

USB 2.0 A Male to Micro 5pin Male 28/24AWG Cable w/ Ferrite Core - (Gold Plated) - 6ft

And I've tried multiple computers & even a USB 3 port.

The port on the phone is USB 2 right?

Also, I'm running CM7. I assume that is perfectly capable of handling USB 2?

 

[BlueBiker]

Ohhhhh, you're writing from the PC to the card while the card's still in the phone. Didn't realize that.

Well the cable sounds more than capable of it. You've ruled out the PC end of it w/multiple PCs. The phone was released in June '10, so it had to come w/USB2 Hi-Speed connection.

I think you've ruled out all of the hardware (assuming the high-spec cable isn't defective, which really isn't likely), so what's left is software. If you put that card in a card reader connected to any of the PCs, I'm sure they'd run fine at full speed. Maybe that revision of CM7 has a buggy USB driver?

UPDATE: Uh-oh, could this be related?

 

[Vastlee]

Ohhhhh, you're writing from the PC to the card while the card's still in the phone. Didn't realize that.

Well the cable sounds more than capable of it. You've ruled out the PC end of it w/multiple PCs. The phone was released in June '10, so it had to come w/USB2 Hi-Speed connection.

I think you've ruled out all of the hardware (assuming the high-spec cable isn't defective, which really isn't likely), so what's left is software. If you put that card in a card reader connected to any of the PCs, I'm sure they'd run fine at full speed. Maybe that revision of CM7 has a buggy USB driver?

UPDATE: Uh-oh, could this be related?

It charges & holds power fine.

Not sure, going to rule a few things out tonight. My buddy has a USB2 drive that uses a Micro USB cable, so I'm going to try that. Also, I'm still leaning on it being a hardware issue. I say that because my original MicroSD card that came with the phone was transferring data from the PC to the phone at the exact same speed. 1.5MB/s. That consistent number seems to indicate that it is infact defaulting to a USB1 speed.

That narrows it down to Port on PC, Cable, or Port on phone. Will update while eliminating more possibilities. Thanks again.

 

[BlueBiker]

I'm seeing an awful lot of google hits for CM7 USB speed. Bet you a virtual beer that's what the problem is.

 

[Vastlee]

I'm seeing an awful lot of google hits for CM7 USB speed. Bet you a virtual beer that's what the problem is.

Uggh... looks like you're right. After testing everything & getting no where I decided to take the ROM out of the equation. So I booted into recovery & mounted the USB from there. Then tried to transfer something.

Sure enough, 8.8MB/s speeds.

I guess I'm glad I found the problem, but I'm not happy since I love CM7 so much. Anyone have any suggestions on how to keep CM7 but fix this USB problem?

This makes me sad

 

[ocnbrze]

moved this thread to the rooting section as it seems that this is where the thread is heading to.

 

[Vastlee]

moved this thread to the rooting section as it seems that this is where the thread is heading to.

Thanks ocnbrze. I was just considering reposting in this area. Hopefully will get some attention as to where I can go from here.

 

[BlueBiker]

I guess I'm glad I found the problem, but I'm not happy since I love CM7 so much. Anyone have any suggestions on how to keep CM7 but fix this USB problem?

The good news is it's already a widely known issue, so 1) they're presumably working on it, and 2) your hardware is fine.

Do the files you want transferred to the SD card have to travel through the USB cable? A typical home WiFi setup might be able to transmit 5-10MB/s, so if CM7 can write to the card directly at full speed then you'll still come out way ahead by moving them wirelessly.

 

[Vastlee]

The good news is it's already a widely known issue, so 1) they're presumably working on it, and 2) your hardware is fine.

Do the files you want transferred to the SD card have to travel through the USB cable? A typical home WiFi setup might be able to transmit 5-10MB/s, so if CM7 can write to the card directly at full speed then you'll still come out way ahead by moving them wirelessly.

It's a good suggestion, but unfortunately I don't have WiFi available at work (Where I need to do the file transfers). I'm going to load the latest version of MikG & see if that helps. I was reading on the CM forums & someone suggested that it wasn't a problem with CM but with the Linux that the Kernal was built on. I was reading that this problem has been around since February so I don't have a lot of faith in it getting fixed before ICS comes around.

 

[BlueBiker]

Wonder why such a major bug hasn't been addressed in almost a year. I think AirDroid only works via local WiFi, but other remote access apps can use any connection to the phone. I guess you could also synchronize a DropBox folder on the card.

 

[Vastlee]

Wonder why such a major bug hasn't been addressed in almost a year. I think AirDroid only works via local WiFi, but other remote access apps can use any connection to the phone. I guess you could also synchronize a DropBox folder on the card.

Switched over to MikG. Getting 5.5MB/s. Vast improvement over the 1MB/s.

 

[dustwun77]

there is an app called quickboot you may have heard of. It makes it real easy to get into recovery. Until they get cm7 straight, I'd just pop into recovery and transfer my files from there.

Actually, I do that anyway.

 

[Granite1]

Dropbox is a good way to transfer files from the computer directly to the phone. I don't know what the download speeds are, but I bet they're faster than 1.5mbps. I think......

 

[BlueBiker]

Switched over to MikG. Getting 5.5MB/s. Vast improvement over the 1MB/s.

Excellent, glad you have a solution!

there is an app called quickboot you may have heard of. It makes it real easy to get into recovery. Until they get cm7 straight, I'd just pop into recovery and transfer my files from there.

Actually, I do that anyway.

Interesting find, I hadn't heard of that before.

 

[dustwun77]

Let me know if you like it.