Tweak SSD performance under Bootcamp

[IA64]

Hello Lipid. I already read about the CPU C-state before finding this tweak but changing only the Idle promote threshold will, for some reason give me 15-20% lower CPU score benchmark.

I run extensive CPU benchmark to rule out any possible degradation with my current CPU power saving settings and this is the best I could find.

 

[Lipid]

Yes, but the highest possible CPU perfomance wasn't the point for me, I was looking only for SSD speed without extra cpu-heat and fan noise. I'm working on a laptop, not desktop. So I'm satisfied with that only 1 tweak, making my CPU run on C1 state all the time and being instantly ready for blazingly fast 4k SSD perfomance. I do not need the CPU run on 2,9ghz all the time and produce extra heat.

 

[IA64]

Yes, but the highest possible CPU perfomance wasn't the point for me, I was looking only for SSD speed without extra cpu-heat and fan noise. I'm working on a laptop, not desktop. So I'm satisfied with that only 1 tweak, making my CPU run on C1 state all the time and being instantly ready for blazingly fast 4k SSD perfomance. I do not need the CPU run on 2,9ghz all the time and produce extra heat.

The point was to tweak the SSD without affecting the overall performance.

Anyway glad it worked for you.

 

[jenzjen]

So if we make only that one change that Lipid highlights, we get the full SSD benefit but maybe 15% slower CPU but slower than max CPU, right? Or another way, with that one change, we are still better than stock speeds on both SSD and CPU?

 

[Lipid]

So if we make only that one change that Lipid highlights, we get the full SSD benefit but maybe 15% slower CPU but slower than max CPU, right? Or another way, with that one change, we are still better than stock speeds on both SSD and CPU?

If you make that only one change you will not get your CPU perfomance reduced in any case. Your CPU perfomance will remain the same. All this tweak does is telling the CPU to stay in C1 state and prevent from going to C2/C3 sleep states. Basically that means that your CPU is ready for action immediately. And this leads to good SSD perfomance. In contrast when yout CPU is sleeping in C3 state it will need some time to wake up and switch to C1 before working as it should.

So in 2 words, when you make that only 1 change:
- your ssd will work much faster
- your cpu will work the same as before

 

[liahim]

Can't understand what is wrong?

I've done all steps as in instructions, but nothing changes.
What is wrong?
MBP mid 2014, SSD sm1024f, Bootcamp 5.1, Windows 7

 

[liahim]

Forget turn on writing cache

Sorry, i forget turn on SSD's writing cache options.
Now another result:

 

[s1l3nce]

For those who might have reached this thread because you are having slower SSD performance on Windows (Bootcamp) compared to macOS, here is a method that worked for me on a 2011 iMac and Macbook Pro.