The RK3399 Overclock/Undervolt/Voltages Thread

[generaleramon]

Stock 4xA53@1416Mhz / 2xA72@1800Mhz / CCI-500@600Mhz
==> Finished making: linux 5.12.9-99 (Sun 06 Jun 2021 03:34:10 CEST)

real 238m40.465s
user 1176m57.838s
sys 82m22.896s

[dsimic]

So, it's 238 vs. 213 minutes, or about 10% faster with the overclock.  It must be that the microSD card is a bottleneck.

[generaleramon]

one funny thing i found out changing the SD bus clock... if i start the laptop with the sd inserted i get this bus speed:

Code:

cat /sys/kernel/debug/mmc1/ios
clock:          50000000 Hz
actual clock:  50000000 Hz
vdd:            18 (3.0 ~ 3.1 V)
bus mode:      2 (push-pull)
chip select:    0 (don't care)
power mode:    2 (on)
bus width:      2 (4 bits)
timing spec:    2 (sd high-speed)
signal voltage: 0 (3.30 V)
driver type:    0 (driver type B)

with and average read rate of 21.2MB/s and an average latency of 0.73msec

simply by reinserting the sd after the login a get this:

Code:

clock:          200000000 Hz  (150000000 is the default max clock)
actual clock:  200000000 Hz
vdd:            18 (3.0 ~ 3.1 V)
bus mode:      2 (push-pull)
chip select:    0 (don't care)
power mode:    2 (on)
bus width:      2 (4 bits)
timing spec:    6 (sd uhs SDR104)
signal voltage: 1 (1.80 V)
driver type:    0 (driver type B)

58.6MB/s Read (peaks of 80MB/s) and 0.57msec Latency

[dsimic]

That's very interesting!  It may be related to the issue with A1-rated microSD cards that I've described in this forum thread.

[generaleramon]

That's very interesting!  It may be related to the issue with A1-rated microSD cards that I've described in this forum thread.

do you have the same problem? SD running at 50000000Hz, and runs at 150000000Hz only if the SD is connected after the bootup

[generaleramon]

[dsimic]

do you have the same problem? SD running at 50000000Hz, and runs at 150000000Hz only if the SD is connected after the bootup

In my case, an A1-rated Kingston microSD card fails to work at SDR104 speed, but limiting the speed of the MMC interface to SDR50, which still runs at 1.8 V, makes the same microSD card work just fine.  The card itself is fine, it works as expected in an external USB 3.0 card reader.

This is getting radical, you've hacked off a portion of the RF can shield.   If this doesn't make the BQ24171 cool, nothing else will.