[linux-audio-user] CPU clock - beware - Solved for now?

[Rick B]

Matthew Barber wrote:

>->I have the same mobo and processor. I couldn't find anywhere in the
>Award BIOS to over clock? Where iz? And I think mine only runs at 166mhz
>fsb. It has 333mhz DDR RAM.<-
>
>
>I could be wrong, but I don't think that with that memory you'd want to
>clock the system bus past 166 (since it's "DDR" -- "double data rate"
>RAM, the actual FSB clock is half of what it says it is)... and I think
>that after a certain point AMD started locking the multiplier capability
>in their athlons since people were overclocking them so much, so you
>can't set the multiplier in the BIOS (I've heard of some workarounds
>that require a CPU modification, but I don't know if they work now).  If
>you got some faster memory, though, you could probably overclock the
>bus.  Am I right about this?
>
>M
>
>
>  
>
   On my bios (rev. 1005) adjusting the CPU frequency is under 
"Advanced>Advanced Chipset Features>Cpu External Frequency". Although 
other settings on the same page dictate how much this value increases or 
decreases (1mhz at a time or 33mhz at a time). I believe that "System 
Performance" must be set to "User Defined" to get 1mhz increases in 
speed. I started thinking about all of this overclocking stuff from a 
article I read on the RME website, here it is:
http://www.rme-audio.com/english/techinfo/nforce2_tweaks_01.htm . This 
article pertains only to the Asus A7N8X mobo with the Nforce2 chipset. 
With my revision 2.0 mobo there was no voltage increase necessary, it 
stayed at 1.65v. However, like the article says, I did have to move the 
CPU speed jumper on the mobo from the 133/166 position to the 100 
position (yes, it sounds wierd, but it works) to get to a 200mhz fsb. 
Also, I set the "AGP Frequency" to 66mhz so its locked at that, and 
there aren't any problems from the video card or pci bus being 
overclocked. Keep in mind though that the older revision 1.* mobo's are 
different than mine, but the RME article covers them also.
  My Athlon 2500 (1yr old) does have the multiplier unlocked and is 
adjustable from the bios. However, the newer 2500's are all locked, ** 
EXCEPT** the Athon-M (mobile) CPU's and those will fit in the same CPU 
socket. Another plus to the Athlon mobile processors is they use less 
voltage (1.45) and withstand higher tempatures (~195F) before they shut 
down (or melt :)) and are just a little more expensive.
       As far as memory is concerned, in the bios there is a setting 
called (ironically) "Memory Frequency", you have the option to run the 
memory at percentages of the processor speed (83%-100%-%125). I was 
fortunate in that my Samsung PC2700 did overclock from 166mhz to 200mhz, 
although I did have to relax the timing's on it from 2-3-2-7 to 3-3-3-8 
and increase the voltage from 2.6v to 2.7v to get it to stabilize. 
However, *it will not pass memtest86* and starts generating errors 
within a hour of running memtest. When I'm doing any kind of recording I 
always run it at %83 of 200mhz (166mhz) just to be safe, otherwise it 
stays at 200mhz, and I don't notice any problems even when the CPU is 
under a high load (%95 utilization) for an extended period of time (4hrs 
or more) while I play Unreal Tournament 2004 the new latest and greatest 
video game available on Linux. When I can afford it I will buy some 
PC3200 memory that has really low latency timings (2-2-2-6).


                Rick B