Though there is technically nothing wrong with your settings! You would get the same effect with:lapoltba wrote:Running Xbian (XBMC) on my Pi. It was rather sluggish and menus took forever to load.
Overclocked today for the first time:
over_voltage = 4
arm_freq = 1000
sdram_freq = 500
gpu_freq = 500
core_freq = 500
h264_freq = 500
isp_freq = 500
v3d_freq = 500
Seemed stable for now. I may try dropping the voltage a bit. What a difference it made. Menus are much snappier and boot is about half the time it was before. Amazing what this little board can do.
Have you tried this with Quake3?wollac11 wrote: The gpu_freq will go up to 550 (that's as much as I've attempted so far) and still boot and seemingly run fine but some games will eventually cause the system to lock up when it's at 500 or 550 so I may need to look into lowering that setting until I find an overclock that's suitable.
As mentioned in this thread I'm pretty certain that a number of the Pis with Samsung RAM has the stuff rated for 533mhz which is why they overclock so easily. Also already stated in this thread, all the boards currently have a cap based on a PLL that from my tests are around ~575mhz but certainly under 600mhz for the RAM. Setting it any higher in the config will result in just getting the max allowed by the PLL.wollac11 wrote: The ram seems to be able to overclock endlessly so I'm guessing something is wrong. I started at 500 and worked up to 800 without any issues which made me suspicious so I randomly tried 1400 and guess what? yep, it booted and ran fine! This leads be to believe that something is not right with my pi or it's config because there is no way that the RAM would run at 1000MHz more than the stock frequency. Is there any way I can check this? Maybe a tool that could tell me what it is actually running at?
Also I don't know how much difference it would make in this case but my Pi has the Samsung memory chip rather than the Hynix one.
No not yet but I'll definitely try getting that installed on my Pi soon and giving it a shot! I'll post back my results once I doshalo wrote: Have you tried this with Quake3?
Ah okay that makes sense, thank you! I must have just missed earlier mentions of this. Anyway, that's a better case scenario than a feared (whereby it was simply ignoring the overclock for some reason). In that case I'll leave it set on 600 for good measure and that should ensure I get the max out of it.shalo wrote: As mentioned in this thread I'm pretty certain that a number of the Pis with Samsung RAM has the stuff rated for 533mhz which is why they overclock so easily. Also already stated in this thread, all the boards currently have a cap based on a PLL that from my tests are around ~575mhz but certainly under 600mhz for the RAM. Setting it any higher in the config will result in just getting the max allowed by the PLL.
You can only really test it. The difference in memory bandwidth from 550 to 600 appears to be marginal though does seem to exist. I believe dom was going to look into it and see what the exact situation is but I doubt it is high priority. The only time you tend to see any difference is in synthetic benchmarks anyway.lapoltba wrote: I just read about the High limit on PLL. Is there any way to check what you are actually running?
Just remember to check when new firmware comes out that the limit wasn't sneakily removed and that it is stable at 600.wollac11 wrote: Ah okay that makes sense, thank you! I must have just missed earlier mentions of this. Anyway, that's a better case scenario than a feared (whereby it was simply ignoring the overclock for some reason). In that case I'll leave it set on 600 for good measure and that should ensure I get the max out of it.
On quake3 with sound, you can use the ingame command at the console /snd_restart I remember it being a touch flakey when using analogue audio at times. Usually requiring a /snd_restart soon after launch.ricsi wrote: <Q3, gpu, ram>
How big is the buffer membench uses?ricsi wrote: Also SDRAM clocking is veeeery strange. I seem to have samsung, and I get this results with the mem bench posted here:
Any ideas why??
I'm just going to go ahead and reiterate, it can't hurt.dom wrote:Latest firmware changes the PLL frequency used.
The PLL is set to the largest N such that core_freq*2*N < 2.4G.
In fact it rounds to nearest even integer, so asking for gpu_freq=300 will result in divisor of 2000/300 = 6.666 => 6 and so 333.33MHz
That sounds correct. I'll see if I can expose a way to actually measure some of these clocks. We have a way on GPU to feed to clock into a counter and see how high it gets in say 1ms.shalo wrote:I'm just going to go ahead and reiterate, it can't hurt.
1. Your PLL will be set from your core_freq. So once you have set your core_freq in your config you will now know your PLL from that first formula.
2. Now you have your PLL, you can divide it by whatever you have set your gpu_freq in your config as. The answer to this step should be rounded to the nearest even number. Then you should divide your PLL again by this new, even number and that is what your gpu is really running at despite what you have set in your config. At this point, you should probably go back into your config and change the gpu_freq to the nearest integer to this if only to show you understand how it works.
Config example: core_freq=455, gpu_freq=270
My PLL will be 455 x 2 x 2 = 1820 (x3 would be 2730 and greater than 2400)
a) 1820 / 270 = 6.74 (so 6, since 7 is an odd number)
b) 1820 / 6 = 303.33...
c) At this point, I should probably go into my config file and change gpu_freq to 303 since that is what I have actually set it at in reality. If nothing else, it will show that I know what I am doing.
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vcgencmd measure_clock V3D result=303334000
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arm_freq=800 sdram_freq=450 gpu_freq=300
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i added that to the wiki.dom wrote:Latest firmware changes the PLL frequency used.
No, I don't think SDRAM overclock has changed. How does boot fail - does it do a reboot loop? Stuck at coloured square? Hangs during linux messages?TarjeiB wrote: No longer boots with the new firmware. Commenting them all out boots fine, I have not yet done further tests.
*EDIT* Commenting outmade it work again, was the ram overclock also changed?
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