Raspberry Pi B+ Overclocking

Question

Good day,

May I ask if it is true that if I activate turbo on the raspi-config, the pi doesn't always run at the maximum speed at 1Ghz.

1. Is it safe to set force turbo = 1 at the config.txt to force the cpu to run at Maximum frequency as long as the temperature does not exceed 85 degrees celsius? However this voids the warranty

2. Also will the command temp_limit = 85, override the force turbo = 1 setting?

3. May I also ask of using this command instead of force turbo by changing the default scaling governor in the /etc/conf.d/cpupower file can achieve a similar effect so as not to void warranty.

   START_OPTS="--governor ondemand"

   STOP_OPTS="--governor performance"

4. I have read that using a raspberry pi B+ due to the more stable power supply, I do not have to worry about corrupt SD cards. Is this true?

   Thank you :)

Reference:

• Raspi Guide: Force Turbo Option

Answer 1

Setting the governor to "performance" should mean the processor runs at the maximum frequency set in config.txt, or the default if there isn't one. Note that this is generally pointless except in unusual contexts, since when required gearing up to a higher frequency happens much faster than is humanly perceivable.

I have read that using a raspberry pi B+ due to the more stable power supply, I do not have to worry about corrupt SD cards. Is this true?

It's possible that to the extent that the earlier models might have been prone to corrupt SD cards due to power issues, the newer models might be better. However, to my knowledge there has never been an admission of such an issue with any of them (discounting defective units, which any piece of electronics can be defective), and I am confident in saying that the vast majority of Pi users have never had any serious issues with SD corruption. However people do not post online that their computer worked fine today, so if you go by reports online, it may appear that there is a significant issue when there is not.

Our reports of such here did seem to peak during a period of time a few years ago before the newer models became predominant, but there may be another explanation for that -- in addition to the user base in general smartening up to the most common cause, which is yanking the cord when the system is very busy, particularly with I/O to the card. If you have to yank the cord for some reason, give it a bit of time to idle if possible and wait until the green ACT light is not blinking furiously. There is no form of power regulation that can prevent this issue on the pi or any other computer, because it really is not the hardware that is "to blame". It's a logical chicken-and-egg type complication of what complex software may be doing when it is arbitrarily interrupted.

You can pay $5000 for a desktop and it will also be subject to a risk of corrupting data on permanent storage if you yank the cord from the wall without shutting it down properly. Electronic devices with writable storage which can be shut down via a button actually go through a process which may take several seconds to help ensure the integrity of stored data. The Pi does not have such a button, but you can implement one or buy such from various third parties.

Answer 2

The B+, Pi2 & Pi3 all have similar power circuitry, which is also more efficient than that in earlier models, but no more reliable.

The vast bulk of power issues are due to lousy power supplies and the lower current requirement of the B+ may make them SEEM more reliable. The Pi2 & Pi3 draw more current, which means they have more issues with poor supplies.

In 3 years, with 5 Pi I have had one SD failure (a new card which was replaced under warranty) and one corruption (during an upgrade) - plus a few "operator error" issues.

I do not believe the power supply affects SD failure, as the SD Card runs off 3.3V (well regulated on all models) and the SOC runs off a combination of lower voltages. Poor supplies mainly affect peripherals.

As for over-clocking WHY? Have you an application which you have benchmarked which indicates over-clocking is effective. You would be better using a Pi2 or Pi3, which have multi-core processors and more memory as well as a higher clock rate.