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 <raa...@gmail.com> 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 >> > -- You received this message because you are subscribed to the Google Groups "linux-sunxi" group. To unsubscribe from this group and stop receiving emails from it, send an email to linux-sunxi+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.