..I am referring to the register in address: 0x01c20250
On Sunday, August 31, 2014 3:30:49 PM UTC+3, RFat wrote:
>
> I saw that when over clocking A31 with AnTuTu the PLL1 Tune changes. I
> have no clue or any documentation as to what this her does (the function of
> its bits).
>
> Anyone has any idea?
>
> Raanan
>
> On Sunday, August 31, 2014 11:59:29 AM UTC+3, RFat wrote:
>>
>> Hi Siahrhei,
>>
>> Thank you for your suggestion. I believe I am turning on the cache by
>> calling:
>>
>>
>> void cpu_dcache_enable(void) {
>>
>> u32 reg ;
>>
>> reg = get_cr();
>>
>> timer_delay_ms(1) ;
>>
>> set_cr(reg | CR_C);
>>
>> }
>>
>>
>> void cpu_icache_enable(void) {
>>
>> u32 reg ;
>>
>> reg = get_cr();
>>
>> timer_delay_ms(1) ;
>>
>> set_cr(reg | CR_I);
>>
>> }
>>
>>
>> which I believe turn on/off C (CP15) bits.
>>
>>
>>
>> I installed Antutu on that hardware (melee a1000g) and managed to
>> over-clock it to 1200Mhz and could make sure it was a real over clocking -
>> meaning that the system indeed became faster.
>>
>>
>> I guess PLL1 is not the only guy that should be dealt with - perhaps
>> someone knows what else?
>>
>>
>> I'll keep looking into this.
>>
>>
>> Thanks again!
>>
>>
>>
>>
>>
>> On Thursday, August 28, 2014 10:13:45 AM UTC+3, Siarhei Siamashka wrote:
>>>
>>> On Mon, 25 Aug 2014 05:43:04 -0700 (PDT)
>>> RFat <[email protected]> wrote:
>>>
>>> > Hi all,
>>> >
>>> > I am trying to overclock the A31 higher than 1008MHz
>>>
>>> Are you fine with the deterioration of reliability and/or overheating
>>> under high load?
>>>
>>> > and I am getting deterioration in performance.
>>> >
>>> > The way I work is execute a small program from u-boot which redefines
>>> the N
>>> > multiplayer of PLL1 and then runs some CPU-intentive routine (to
>>> measure
>>> > performance).
>>> >
>>> > Here are the results I get (the N multiplier is given in the small
>>> brackets
>>> > starting from 18):
>>> >
>>> > CPU Freq = 864Mhz (18)
>>> > run in 10Hz, 94ms
>>> > PLL1 is ENABLED P:2 M:1 K:3 N:18 Sigma:0 Lock:0 Freq:432Mhz
>>> coreclk:864Mhz
>>> > CPU Freq = 912Mhz (19)
>>> > run in 11Hz, 89ms
>>> > PLL1 is ENABLED P:2 M:1 K:3 N:19 Sigma:0 Lock:0 Freq:456Mhz
>>> coreclk:912Mhz
>>> > CPU Freq = 960Mhz (20)
>>> > run in 11Hz, 85ms
>>> > PLL1 is ENABLED P:2 M:1 K:3 N:20 Sigma:0 Lock:0 Freq:480Mhz
>>> coreclk:960Mhz
>>> > CPU Freq = 1008Mhz (21)
>>> > run in 12Hz, 81ms
>>> > PLL1 is ENABLED P:2 M:1 K:3 N:21 Sigma:0 Lock:0 Freq:504Mhz
>>> coreclk:1008Mhz
>>> > CPU Freq = 1056Mhz (22)
>>> > run in 12Hz, 77ms
>>> > PLL1 is ENABLED P:2 M:1 K:3 N:22 Sigma:0 Lock:0 Freq:528Mhz
>>> coreclk:1056Mhz
>>> > CPU Freq = 1104Mhz (23)
>>> > run in 9Hz, 101ms
>>> > PLL1 is ENABLED P:2 M:1 K:3 N:23 Sigma:0 Lock:0 Freq:552Mhz
>>> coreclk:1104Mhz
>>> > CPU Freq = 1152Mhz (24)
>>> > run in 9Hz, 101ms
>>> > PLL1 is ENABLED P:2 M:1 K:3 N:24 Sigma:0 Lock:0 Freq:576Mhz
>>> coreclk:1152Mhz
>>> > CPU Freq = 1200Mhz (25)
>>> > run in 9Hz, 101ms
>>> > PLL1 is ENABLED P:2 M:1 K:3 N:25 Sigma:0 Lock:0 Freq:600Mhz
>>> coreclk:1200Mhz
>>> > CPU Freq = 1248Mhz (26)
>>> > run in 9Hz, 101ms
>>> > PLL1 is ENABLED P:2 M:1 K:3 N:26 Sigma:0 Lock:0 Freq:624Mhz
>>> coreclk:1248Mhz
>>> > CPU Freq = 1296Mhz (27)
>>> > run in 9Hz, 101ms
>>> > PLL1 is ENABLED P:2 M:1 K:3 N:27 Sigma:0 Lock:0 Freq:648Mhz
>>> coreclk:1296Mhz
>>> > CPU Freq = 1344Mhz (28)
>>> > run in 9Hz, 101ms
>>> > PLL1 is ENABLED P:2 M:1 K:3 N:28 Sigma:0 Lock:0 Freq:672Mhz
>>> coreclk:1344Mhz
>>> > CPU Freq = 1392Mhz (29)
>>> > run in 9Hz, 101ms
>>> > PLL1 is ENABLED P:2 M:1 K:3 N:29 Sigma:0 Lock:0 Freq:696Mhz
>>> coreclk:1392Mhz
>>> >
>>> > As you can see, after 1008 (or 1056) there's a _decrease_ in
>>> performance.
>>>
>>> I can see that the performance flattens out and remains at the same
>>> 101ms level for your CPU-intensive routine.
>>>
>>> If you are running the code in u-boot from SRAM and the L1 cache is not
>>> enabled, then the instructions fetch may become a bottleneck.
>>>
>>> > Does anyone knows how higher performance can be achieved?
>>>
>>> Maybe buy a different higher performance SoC or better optimize the
>>> software?
>>>
>>> --
>>> Best regards,
>>> Siarhei Siamashka
>>>
>>
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