Pi3 Overclocking/Overheating issues

Machtroid

Hello all, I am having some overheating issues it seems. I have a Pi3 with the latest versions of Raspbian Jessie and Retropie. My board is in an official casing (top open) with a heatsink on both CPU and GPU , sitting in an environment that is no warmer than 65C. My overclock settings are as follows:

arm_freq=1350
core_freq=500
sdram_freq=500
over_voltage=5
temp_limit=80

Also using on-board bluetooth for PS3 controller. Power supply is 5.25V.

I don't believe this to be too aggressive of an overclock. I've read posts on various users settings before trying my own. However after anywhere from 30-45 minutes of playing PSX and/or SNES the Pi will freeze and I will get the yellow/orange square in the upper right corner. I can't even SSH into the Pi to check the temp since it is a complete seize up. I dialed it back for now to avoid the freeze. Am I doing something wrong here? I know the Pi3 runs warmer than the Pi2, however my OC settings on the Pi2 were just a shade under what I have here, with no open-air case or heatsink, and it never overheated like this. Any advice is appreciated.

RetroResolution

@Machtroid hi,
I've written some guides on overclocking and, most importantly, testing which you may wish to try so you'll have a quantifiable view of your machine's stability:

Overclocking the Raspberry Pi 3: Thermal Limits and Optimising for Single vs Multicore Performance

Overclocking and Stability Testing the Raspberry Pi

You mention an ambient temp of 65c, which seems awfully high.

As I recently wrote in another thread:
@Parzival I have a Pi 1, 2, and 3, all overclocked. The Pi 3 can generate a lot more heat than the earlier models, but whether it is an issue depends in what you use it for.

The emulators in RetroPie are all, as far as I have observed, single-threaded - only one of the four CPU cores is used, which limits the temperature. If you run multithreaded processes, such as compiling software, or transcoding video, the system rapidly heats up. By default however, at 80 degrees Celsius the 'governor' will throttle back the CPU to keep the temperature at or under the threshold.

The pi 3 has plenty of power compared to the earlier models, and all but the really power-hungry emulators (such as n64 and Dreamcast) will be fine without overclocking.

Machtroid

@RetroResolution good information here thanks! I am testing it now with arm_freq=1300 and over_voltage=4 and I have been good for an hour or so of game time. The reason I overclock is primarily to run PSX with the enhanced resolution mod at 1080P. I don't bother with N64 or DC. Would using a bluetooth controller make the CPU temp much greater than using a USB wired controller? I have other options I might try there as well.

RetroResolution

@Machtroid hi,

I'm not sure if using Bluetooth will have much effect on temperature, but it depends in the efficiency of the drivers.

I run a lot of PlayStation games in enhanced resolution, and all appears rock-solid. Only Gran Turismo 2 appears to be pushing the limits of the system (overclocked at 1350MHz).

In my experience attempting to overclock the ram always introduces instability (exposed under stress testing) - this is the case on both my Pi 2 and Pi 3.

RetroResolution

@Machtroid I forgot to mention earlier that I've never successfully overclocked the sdram, even mildly, either on a pi 2 or pi 3. Even 25mhz increases are unstable (when soak tested long enough).