Hardware: Raspberry Pi - Revision history

Lukas Dzunko: /* SD Card speed */

2016-02-13T17:39:47Z

‎SD Card speed

Lukas Dzunko: /* SD Card speed */

2016-02-13T17:39:34Z

‎SD Card speed

Lukas Dzunko: /* SD Card speed */

2016-02-13T17:39:25Z

‎SD Card speed

Lukas Dzunko: /* SD Card speed */

2016-02-13T17:39:05Z

‎SD Card speed

Lukas Dzunko: /* Uptime contest */

2016-02-13T17:23:34Z

‎Uptime contest

Lukas Dzunko: /* Temperature */

2016-02-13T17:13:52Z

‎Temperature

Lukas Dzunko: /* Power */

2016-02-13T17:09:25Z

‎Power

Lukas Dzunko: /* Power */

2016-02-13T17:08:55Z

‎Power

Lukas Dzunko: /* Power */

2016-02-13T17:02:32Z

‎Power

Lukas Dzunko: /* Power */

2016-02-13T17:02:08Z

‎Power

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 == SD Card speed ==
-Raspberry Pi use connection which allow only "Class 10" connection to SD Card. This is limiting maximum throughput to SD Card and is source of differed kind of discussion. Which card is better for Raspberry Pi ? I saw responses "Class 4", also "Class 10 is enought" and then "UHS-I Ultimate".<br><br>
+Raspberry Pi use connection which allow only "Class 10" connection to SD Card. This is limiting maximum throughput to SD Card and is source of differed kind of discussion. Which card is better for Raspberry Pi ? I saw responses "Class 4", also "Class 10 is enought" and then "UHS-I Ultimate".
 I did test in past but unfortunately I don't preserve test output details :( So no numbers but at least details:
 * Class 4 -> Throughput limited by card to 4MB/s. Random operations show poor results mostly likely due to throughput limitation.

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 '''Note 1:''' Above test is specific to first version of Raspberry Pi. RPi2 don't have such a limitation on SD Card connection (I see  65MB/s of write and 154MB/s of read on my RPi2 with UHS-I Ultimate SD Card).
-''Note 2:''' I use only Kingston SD Cards.
+'''Note 2:''' I use only Kingston SD Cards.
 == Troubleshooting ==

@@ Line 270: / Line 270: @@
 * UHS-I Ultimate -> Throughput limited by RPi. Random operations show good result regardles of size of IO. I think this may be due to internal "IO capacity" of SD Card.
-'''Note:''' Above test is specific to first version of Raspberry Pi. RPi2 don't have such a limitation on SD Card connection (I see  65MB/s of write and 154MB/s of read on my RPi2 with UHS-I Ultimate SD Card)
+'''Note 1:''' Above test is specific to first version of Raspberry Pi. RPi2 don't have such a limitation on SD Card connection (I see  65MB/s of write and 154MB/s of read on my RPi2 with UHS-I Ultimate SD Card).
 == Troubleshooting ==

@@ Line 264: / Line 264: @@
 == SD Card speed ==
-TODO:
+Raspberry Pi use connection which allow only "Class 10" connection to SD Card. This is limiting maximum throughput to SD Card and is source of differed kind of discussion. Which card is better for Raspberry Pi ? I saw responses "Class 4", also "Class 10 is enought" and then "UHS-I Ultimate".<br><br>
 == Troubleshooting ==

@@ Line 261: / Line 261: @@
 </pre>
-'''Note:''' looks like there is still bug in this package. If NTP change date, then this software detect it as new boot and it create new entry in uptime table. This may occur shortly after bootup so there can be duplicates with short uptime (2:20 and 1:21 is example). I hope this will be fixed in next release. It is not affecting top uptime calculation.
+'''Note:''' looks like there is still bug in this package. If NTP change time/date significantly (during boot or if synchronization is not stable) then this software detect it as new boot entry. This may lead to duplicate entries shortly after boot or several entries covering one uptime. If you notice this behavior then check your time synchronization and/or internet connection.
 == SD Card speed ==

@@ Line 81: / Line 81: @@
 == Temperature ==
-I was trying to get clear answer "what is safe temperature" for Raspberry Pi and apparently there is no clear statement. From my findings safe temperature is up to 60C and shutdown temperature should be 70C. Although it looks like RPi can run up to 80C running close to this temperature can reduce board lifetime. Current temperature measured by SoC itself can be displayed by <code>vcgencmd</code> command or by direct read from <code>/proc</code> file system.
+I was trying to get clear answer "what is safe temperature" for Raspberry Pi and apparently there is no clear statement. From my findings safe temperature is up to 60C and shutdown temperature should be 70C. Although it looks like RPi can run up to 80C. Running close to this temperature can reduce board lifetime. Current temperature measured by SoC itself can be displayed by <code>vcgencmd</code> command or by direct read from <code>/proc</code> file system.
 <pre>
@@ Line 88: / Line 88: @@
 </pre>
-'''FYI 1:''' original plastic case with ventilation opening in RPi logo is concentrating heat. If i open this case temperature drop for more that 10C.
+'''FYI 1:''' original plastic case with ventilation opening in RPi logo is concentrating heat. Test show that this case cause board to head-up by 10C.
-'''FYI 2:''' small "ram" heatsink don't change temperature too much especially if adhesive side is cheaper with significant thermal resistance. I tried several heatsinks and result was only 2 to 5 degree Celsius temperature drop.
+'''FYI 2:''' small "ram" heat sink don't change temperature too much especially if adhesive side is cheaper with significant thermal resistance. I tried several heat sinks and result was only 2 to 5 degree Celsius temperature drop.
 '''FYI 3:''' My recommendation for case: [http://www.emko.cz/en/catalog/it-cases/raspberry-pi/em-raspi-b-silver-h2828 EM-RasPI B+] by [http://www.emko.cz/en EMKO Case]

@@ Line 9: / Line 9: @@
 * [http://sk.farnell.com/jsp/search/productdetail.jsp?SKU=2254794 RASPBERRY PI PSU] is only 1A PSU, so no "hungry" devices. I Have ADATA N005 64GB USB flash disk + receiver for air mouse connected and it is just fine.
 * [http://sk.farnell.com/stontronics/t5582dv/psu-raspberry-pi-5v-2a-micro-usb/dp/2427499 STONTRONICS T5582DV] Recomended for RPi2 and installation which require more current (e.g. many peripherals connected).
 == Boot configuration ==

@@ Line 8: / Line 8: @@
 My Raspberry Pi is running pretty stable with following power sources:
 * [http://sk.farnell.com/jsp/search/productdetail.jsp?SKU=2254794 RASPBERRY PI PSU] is only 1A PSU, so no "hungry" devices. I Have ADATA N005 64GB USB flash disk + receiver for air mouse connected and it is just fine.
 * [http://www.alza.sk/powerocks-stone-3-bila-d338702.htm Powerocks Stone 3] this can act as UPS, but there is still question what is impact of this usage on battery. Only this device provide power at almost exactly 5.00 volts also under load.
 == Boot configuration ==

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 According to details from RPi project voltage between 4.75 and 5.25 volts is fine. I personally preffer voltage between 4.80 and 5.00 volts. Voltage below 4.8 volts, can lead to instability of 3v3 regulator (RG2) (e.g. SoC power source) and connected equipment. Voltage above 5.00 (5.25) can shorten life of board and lead to problems with connected equipment. Voltage above 5.6V trip D17 over voltage protection diode. Make sure that connected USB hub (if any) is not back feeding power. It can cause serious problems as there is no protection on USB output ports.
-If you are experiencing random USB device disconnects, repeating keys from keyboard or random reboots (hung) of board then there is something wrong with power source. I think USB charger as source was not so good decision as most of the chargers don't maintain stable voltage inter load. This can lead to under voltage and cause stability problems. If you hit some of them, then try to measure voltage between test points or change power source.
+If you are experiencing random USB device disconnects, repeating keys from keyboard or random reboots (hung) of board then there is something wrong with power source. I think USB charger as source was not so good decision as most of the chargers don't maintain stable voltage under load. This can lead to under voltage and cause stability problems. If you hit some of them, then try to measure voltage between test points or change power source.
 My Raspberry Pi is running pretty stable with following power sources: