Overclock stability
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So I recently upgraded to a pi3 and I would like to get as much performance out of it for N64 games. So I have started testing overclock settings. The wiki was great explaining what each parameter did and I was able to grasp the basic concept fairly quickly. As I would increase the clock speed I would check each setting by running a N64 game to see if there were any improvements and for stability. If the emmulator crashed or froze or had any other bizarre behavior I would back it off to the last stable setting (like the wiki says). I finally settled on overclocking the arm to 1.45ghz, the GPU/core freq to 525mhz and the ram to 500 with an overvolt of 6. N64 emulation was much improved with these settings and I was able to play for long stretches of time and never ran into any problems (I have a 15x15x15 heatsink and fan, so I haven't run into any cooling issues). For the heck of it I decided to install quake 3 and run it through the paces just to make sure everything was sound. Long story short it was not stable. Quake 3 froze almost as soon as the level loaded, I slowly had to back the arm down to 1.3ghz before it was stable. I have never seen the over heat or low voltage warnings at all during testing. So my question is can I use the higher overclock if I'm not planning on playing quake 3? I had no issues with those settings while playing N64 games. My instinct tells me I already know the answer to this question but figured I would double check with those who know more. Thanks in advance!
Edit: also can anyone speak from experience whether forcing turbo gives any significant improvements? If not I won't bother with it.
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Well after some further extensive testing, I have concluded that eventually my pi freezes up while running 1.45ghz overclock no matter what. So I think I have answered my first question and will be sticking with 1.3ghz.
Although if anyone has some insights into the force_turbo setting and how effective it is for improving performance that would be great.
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Try this link for a detailed explanation :
https://www.raspberrypi.org/documentation/configuration/config-txt/overclocking.md
These are what I use for kodi/retropie and work fine. Temps never get about 45c with a stress test or watching 720p films through KODI. Played full HD movies via KODI and they play perfectly
boot_delay=1
gpu_mem_1024=256
hdmi_ignore_cec_init=1
disable_overscan=1
start_x=1
disable_splash=1
sdtv_aspect=1
gpu_mem_512=256
arm_freq=1400
core_freq=575
over_voltage=6
force_turbo=1
sdram_freq=550
temp_limit=80
h264_freq=340
avoid_pwm_pll=1
gpu_mem_256=128
v3d_freq=520
gpu_freq=400
sdram_schmoo_0x02000020
over_voltage_sdram_p=6
over_voltage_sdram_i=4
over_voltage_sdram_c=4
dtparam=sd_overclock=90
overscan_scale=1The option "bootdelay=1" is just to give USB hard drives a chance to be detected as I've got RetroPie running via KODI 18 not the usual RetroPie with KODI option. Works perfectly as far as RetroPie is concerned and I have OSMC installed to boot from a 1TB portable USB hard drive so the SD card is literally for the boot code then everything runs off the hard drive so the sd card isn't actually used except to boot the PI
It seems 1400 is about the limit for the CPU, maybe a touch more but realistically that's about it. Without taking the RPI case apart I think my custom heatsink is about 20x20x25. I ordered a big heatsink off ebay and cut it down to size as the PI ones off ebay are far too small
Maybe you could try thermal glue. Pretty much good quality thermal paste but mixed in with a slow acting glue, so needs to be left overnight to fully cure. The heatsink is never coming off. Those double sided thermal pads failed miserably for me but tried thermal glue I stumbled across searching one day and it works perfectly. Cost me about £2 with postage (in UK) for a small tube and plenty left over as you only need a very small amount
That is the brand I used. You can pay much much more but this worked for me
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@steptoe thanks for the advice but with my current setup heat really isn't the issue I am using a decent heat sink and fan combo. Even when I was running 1.45ghz it would never get above 52°c. I never got a over heat or under volt warning. The pi just froze up eventually because the setting was unstable I am assuming.
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@quicksilver From https://www.raspberrypi.org/documentation/configuration/config-txt/overclocking.md:
force_turbo Forces turbo mode frequencies even when the ARM cores are not busy. Enabling this may set the warranty bit if over_voltage_* is also set.
I don't think it would have much effect on performance, but it will certainly make your Pi run hotter.
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