Madshrimps Forum Madness - Another P55 round-up: Asus/Asus/DFI

Coming back to the HDD issue, this is what THG said:

Quote:

In short: really fast SSDs that can deliver 200 MB/s or even more of throughput become limited by CPU performance due to power saving mechanisms—or more precisely, they are bottlenecked by a limited availability of CPU time.

Assuming that this hypothesis is correct, we should see this kind of behavior when manually decreasing the CPU multiplier. Assuming that the PCMark HDD test results are accurate, we can see that:

- 3.80GHz = 84000
- 2.67GHz = 80000

The result when enabling the power-saving settings, the result is around 52000. In theory, these power-saving settings decrease the CPU multiplier to the lowest possible value, in this case "12x133" = 1600MHz.

So, there are two possibilities:

1) The hypothesis is correct and the HDD transfer rate is affected mostly because of the reduces amount of CPU cycles.
2) The hypothesis is incorrect and the HDD transfer rate is affected by another cause, possibly in interaction with the reduced CPU cycles.

There's an easy test to test the hypothesis: if the reduced CPU cycles are indeed the cause of the sudden drop in HDD performance, we should see the same behavior when manually decreasing the CPU multiplier while disabling all power saving features. If the hypothesis is correct, we should find a logarithmic relation between HDD tranfer rate and CPU cycle: the lower the clock frequency, the faster decrease in HDD performance. If we find a different relation, eg linear, we'll see that the performance result when enabling power-saving technology differs from the performance result obtained when manually decreasing the CPU multiplier.

Sadly enough, I don't have the tools to measure the performance right now as the Acard is at a colleagues place.