Abro este hilo para comentar el tema del overclocking de la Pi, tema necesario para las aplicaciones que mas cpu piden, como emuladores de plataformas modernas.
La Raspberry de fabrica viene con estos valores:
Para realizar el overclock podemos modificar los valores siguentes en el fichero config.txt, en la particion /boot de la SD:Código:CPU: 700 mhz Core (GPU + bus del sistema): 250 mhz Memoria: 400 mhz
Hay que tener en cuenta que para subir las frecuencias base hay que refrigerar la consola adecuadamente o tendremos bloqueos.Código:arm_freq Frequency of ARM in MHz. Default 700 gpu_freq Sets core_freq, h264_freq, isp_freq, v3d_freq together. Default 250 core_freq Frequency of GPU processor core in MHz. It has an impact on ARM performance since it drives L2 cache. Default 250 h264_freq Frequency of hardware video block in MHz. Default 250 isp_freq Frequency of image sensor pipeline block in MHz. Default 250 v3d_freq Frequency of 3D block in MHz. Default 250 avoid_pwm_pll Don't dedicate a pll to PWM audio. This will reduce analogue audio quality slightly. The spare PLL allows the core_freq to be set independently from the rest of the gpu allowing more control over overclocking. Default 0 sdram_freq Frequency of SDRAM in MHz. Default 400 over_voltage ARM/GPU core voltage adjust. [-16,8] equates to [0.8V,1.4V] with 0.025V steps. [5] Default is 0 (1.2V). Values above 6 are only allowed when force_turbo or current_limit_override are specified (which set the warranty bit) over_voltage_sdram Sets over_voltage_sdram_c, over_voltage_sdram_i, over_voltage_sdram_p together over_voltage_sdram_c SDRAM controller voltage adjust. [-16,8] equates to [0.8V,1.4V] with 0.025V steps. Default 0 (1.2V) [5] over_voltage_sdram_i SDRAM I/O voltage adjust. [-16,8] equates to [0.8V,1.4V] with 0.025V steps. Default 0 (1.2V)[5] over_voltage_sdram_p SDRAM phy voltage adjust. [-16,8] equates to [0.8V,1.4V] with 0.025V steps. Default 0 (1.2V)[5] force_turbo Disables dynamic cpufreq driver and minimum settings below. Enables h264/v3d/isp overclock options. Default 0. May set warranty bit. initial_turbo Enables turbo mode from boot for the given value in seconds (up to 60) or until cpufreq sets a frequency. Can help with sdcard corruption if overclocked. Default 0 arm_freq_min Minimum value of arm_freq used for dynamic clocking. Default 700 core_freq_min Minimum value of core_freq used for dynamic clocking. Default 250 sdram_freq_min Minimum value of sdram_freq used for dynamic clocking. Default 400 over_voltage_min Minimum value of over_voltage used for dynamic clocking. Default 0 temp_limit Overheat protection. Sets clocks and voltages to default when the SoC reaches this Celsius value. Setting this higher than default voids warranty. Default 85 current_limit_override Disables SMPS current limit protection when set to "0x5A000020". Can help if you are currently hitting a reboot failure when overclocking too high. May set warrany bit.
Con unos disipadores pasivos, sin ventilador siquiera, son mas que suficiente:
Usando este sistema he llegado a un tope de:
La configuracion que he usado:Código:CPU: 1133 mhz Core (GPU + bus del sistema): 400 mhz Memoria: 600 mhz
Aqui uso unos parametros de sobrevoltaje bastante altos, aunque he probado en varias Pis, de diferentes modelos, y aun no he tenido problemas, aunque segun dicen, se pueden dañar. Yo aun no he visto ningun problema, pero vamos, avisados estaisCódigo:arm_freq=1133 core_freq=400 sdram_freq=600 over_voltage=12 # Aunque el valor maximo en teoria es 8, hasta 12 tambien funciona ;) over_voltage_sdram=8
Con estos valores he puesto el emu de 32x a 50fps estables en juegos pal y teniendo los renders accurate y sonido a 44110 stereo
Mas adelante quiero ver sistemas de refrigeracion activa, peltier y demas, ya que veo que el sistema da mucho margen para el overclock, ya seguire comentando.
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Iniciado por JoJo_ReloadeD
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