Raspberry Pi Forums

Hi, I just got my 512Mb Raspberry Pi.
1) I am using a Sandisk 4GB Ultra II Class 4 SD card and the
2012-10-28 Raspbian “wheezy” image. I am getting a terrible
lag. After I double click an icon on the desktop or select a
program in the menu, it take like 10 or more seconds to load
the program. I tried "reinstalling" the OS and that didnt help.
2) Another problem I am having is that whenever my keyboard
(Logitech G15) is plug in thru the USB hub (IOGEAR GHU286),
it will repeat keys and sometime lags. However, if I plug in
directly, it wont do it. I tried using my keyboard via the USB hub
on my win7 machine and it works perfectly.

1) is probably attributable to the CLASS 4 SD Card you are using. Although a Class 4 Card will work, the data rate is much slower (especially when writing) than a Class 10 Card.

2) is caused by the volt drop between your PSU and the RPi, across the RPI MisroUSB socket Polyfuse and then the cabling to your Hub and Keyboard. I use a POWERED Hub and then power the RPi by backfeeding the USB sockets. This way you circumvent the volt drop inherent in MicroUSB cables, the plug/ socket and the RPi's Polyfuse. The repeating characters from the keyboad usually occur when the Voltage drops below ~4.7 Volts.

and the RPi's Polyfuse.

But he said:-

I just got my 512Mb Raspberry Pi.

So that means it is an issue 2 board and has no ploy fuses in the USB.

There is an unfixable problem with the USB that can cause key repeats on perfectly usable keyboards. Often the most expensive keyboards are a problem. It is a problem of dropping packages, the package dropped has the key up event it it. So it thinks you have the key pressed down. This is worse when going through a hub as it is another place a package can be dropped. The only real solution is to get a cheap keyboard the sort of £6.00 you get in supermarkets.

Grumpy Mike wrote:

and the RPi's Polyfuse.

But he said:-

I just got my 512Mb Raspberry Pi.

So that means it is an issue 2 board and has no ploy fuses in the USB.

Not quite. The Rev 2 Boards still have a Polyfuse just inboard of the MicroUSB socket. This is why I suggest powering the RPi through the USB sockets where the Polyfuses have been omitted.

Grumpy Mike wrote:

and the RPi's Polyfuse.

But he said:-

I just got my 512Mb Raspberry Pi.

So that means it is an issue 2 board and has no ploy fuses in the USB.

There is an unfixable problem with the USB that can cause key repeats on perfectly usable keyboards. Often the most expensive keyboards are a problem. It is a problem of dropping packages, the package dropped has the key up event it it. So it thinks you have the key pressed down. This is worse when going through a hub as it is another place a package can be dropped. The only real solution is to get a cheap keyboard the sort of £6.00 you get in supermarkets.

It's not classified as unfixable. It's being worked on, so is currently unfixed, not unfixable.

Wheel_nut wrote:1) is probably attributable to the CLASS 4 SD Card you are using. Although a Class 4 Card will work, the data rate is much slower (especially when writing) than a Class 10 Card.

2) is caused by the volt drop between your PSU and the RPi, across the RPI MisroUSB socket Polyfuse and then the cabling to your Hub and Keyboard. I use a POWERED Hub and then power the RPi by backfeeding the USB sockets. This way you circumvent the volt drop inherent in MicroUSB cables, the plug/ socket and the RPi's Polyfuse. The repeating characters from the keyboad usually occur when the Voltage drops below ~4.7 Volts.

So I should use an USB port on my USB hub to power my RPi??
My USB hub is powered

Wheel_nut wrote:1) is probably attributable to the CLASS 4 SD Card you are using. Although a Class 4 Card will work, the data rate is much slower (especially when writing) than a Class 10 Card.

I dont think is the SD card. It enough lags during web browsing, eg scrolling up and down, typing into search box, etc.