9x333, 8x375, or 7x428 on a Q6600 - Which is faster?

[graysky]

What is a better overclock?

 

Good question. Most people believe that a higher FSB and lower multiplier are better since this maximizes the bandwidth on the FSB. Or is a low bus rate and higher multiplier better? Or is there no difference? I looked at three different settings on my Q6600:

 

9x333 = 3.0 GHz (DRAM was 667 MHz)

8x375 = 3.0 GHz (DRAM was 750 MHz)

7x428 = 3.0 GHz (DRAM was 856 MHz)

 

The DRAM:CPU ratio was 1:1 for each test and the voltage and timings were held constant; voltage was 2.25V and timings were 4-4-4-12-4-20-10-10-10-11.

 

After the same experiments, at each of these settings, I concluded that there is no difference for real world applications. If you use a synthetic benchmark, like Sandra, you will see faster memory reads/writes, etc. with the higher FSB values -- so what. These high FSB settings are great if all you do with your machine is run synthetic benchmarks. But the higher FSB values come at the cost of higher voltages for the board which equate to higher temps.

 

I think that FSB bandwidth is simply not the bottle neck in a modern system... at least when starting at 333. Perhaps you would see a difference if starting slower. In other words, a 333 MHz FSB quad pumped to 1333 MHz is more than sufficient for today

[graysky]

I just read the FSB1333 Intel Processors & New 2007 CPU Charts article over at TH.com and am happy to see that the testers over there have drawn the same conclusion that I have about fixed final core speeds with higher and higher FSB speeds: faster FSB speeds w/ a C2Q/C2D don't equate to faster real-world benchmarks.

 

Have a look at page 8 from their article comparing the "old" 1066 MHz FSB to the "new" 1333 MHz FSB chips: average gain <1 %.