60Gh/s BFL Singles SC - Overcloking

[Zubilica]

Does anyone has successfully overclocked a Single . For more than 65-70 Gh/s ?

[1715391194]

1715391194

[joeventura]

The most a BFL single can hash at with all Grade A chips is 64Gh

Remember your math:

16 Chips per single
each chip has 16 engines of 0.250 Gh
16 X 0.250 = 4 Gh per chip
4 X 16 = 64Gh

Each single has to have 16 perfect Grade A chips to hash at 64Gh

[philips]

Higher grade chips will run up to 294Mhz (I've seen engines running at 320Mhz). At the same time, I think you can use only 15 engines per chip.

[SgtSpike]

How do you actually attempt to overclock an SC Single?

[philips]

The same as with the Jalapeno, but probably with less spectacular results.

[tymothy]

The same as with the Jalapeno, but probably with less spectacular results.

Basically this. Take a look at my thread https://bitcointalk.org/index.php?topic=258643.0

[tymothy]

Higher grade chips will run up to 294Mhz (I've seen engines running at 320Mhz). At the same time, I think you can use only 15 engines per chip.

Interesting, I'm not sure how the firmware clocks the chips exactly. There's this portion in the header file:

//#define __OPERATING_FREQUENCY_16MHz__
//#define __OPERATING_FREQUENCY_32MHz__
//#define __OPERATING_FREQUENCY_48MHz__
#define __OPERATING_FREQUENCY_64MHz__
...
ifdef __OPERATING_FREQUENCY_64MHz__
   #define NOP_OPERATION asm volatile ("nop \n\t nop \n\t nop \n\t nop \n\t nop \n\t");
#elif defined(__OPERATING_FREQUENCY_48MHz__)   
   #define NOP_OPERATION asm volatile ("nop \n\t nop \n\t nop \n\t nop \n\t");
#else
   #define NOP_OPERATION asm volatile ("nop \n\t nop \n\t nop \n\t nop \n\t");

Does 64Mhz relate to the chip or engine frequency or something else? If it does relate to chip speed, what does "nop \n\t nop \n\t nop \n\t nop \n\t nop \n\t" mean or refer to? I have a fairly limited background in programming and I'm not intimately familiar with the board design or exactly how jobs get distributed and calculated across chips and engines.