Laptop with i9-8950hk not reaching anything beyond c2 state

[lifer16]

Hello, I have an Alienware 17 r5 laptop with a gtx 1080, i9-8950hk, 32gb ddr4 ram, tobii eye and gsync(intel hd graphics are disabled because of it,so no optimus) and I been unable to reach beyond c3 in the past around a year ago, but nowadays my laptop is stuck at c2, I have tried everything from reinstalling the ide ata drivers to playing around in throttlestop with the cpu but nothing, hopefully someone has an idea and can provide some help, thanks

 

[unclewebb]

My desktop 10850K had this same problem. Installing the Intel IDE / ATA driver allowed me to finally use package C3.

It could be any driver on your computer preventing this. Maybe the Nvidia GPU driver is deliberately blocking package C3. If you have not seen package C3 in over a year then it is going to be very difficult to get this working again. I do not think it would be a good idea installing year old drivers trying to solve this problem.

For myself, getting package C3 working created more problems than it solved. When package C3 is enabled, I get random and continuous static noises through my speakers when listening to anything. I thought I was going to have to RMA my motherboard or else buy an external sound card. It was horrible. I used ThrottleStop to disable package C3 and now the sound is crystal clear. The change happens instantly and is repeatable. Now I leave package C3 disabled.

The difference in power consumption between package C2 and package C3 is minimal.

 

[The red spirit]

I have read that some CPUs have faulty C states and machine would crash if it was let to enter them. That should mostly affect C7-C10 states, not C3-C6. Not sure if you tried, but try using different power plans, particularly power saver to see if it does anything.

My desktop 10850K had this same problem. Installing the Intel IDE / ATA driver allowed me to finally use package C3.

For myself, getting package C3 working created more problems than it solved. When package C3 is enabled, I get random and continuous static noises through my speakers when listening to anything. I thought I was going to have to RMA my motherboard or else buy an external sound card. It was horrible. I used ThrottleStop to disable package C3 and now the sound is crystal clear. The change happens instantly and is repeatable. Now I leave package C3 disabled.

The difference in power consumption between package C2 and package C3 is minimal.

i9 should be capable to go into C10 state. It's odd that yours goes only to C3 and you need workarounds for that to work. Pretty much every Intel chip since Haswell is capable of going as low as C10 state. Like you said power consumption difference is almost nonexistant. For me that's maybe a watt at idle if that.

 

[unclewebb]

It's odd

The Intel documentation shows all of the package C states that are available but there are a lot of issues with poorly written drivers. The package power C states rarely work as advertised.

every Intel chip since Haswell is capable of going as low as C10 state

With Haswell CPUs, I think only the low power 15W U series support package C10. My 4700MQ mobile CPU only supports package C6. I believe package C7 was deliberately disabled to improve stability. There were a few stability issues during the early days of package C states so I think some manufacturers got in the habit of disabling these rather than waste time trying to get them to work reliably.

The 8th to 10th Gen mobile H series CPUs all support package C8 but this is rarely used. Laptops are shipped and no one seems to care if the package C states are working correctly or not. Review sites never check so no one is aware of this problem. I recently saw a couple of pics of 11th Gen CPUs that were finally using package C10. It has only taken 7 years for manufacturers and Microsoft to start looking into these issues.

I was helping a user earlier this week with his powerful 10870H laptop. Someone at Acer thought it would be a good idea to disable ALL of the C states. Not just the package C states but they released an update that disabled all of the core C states too. This bad idea will prevent Intel Turbo Boost from functioning correctly. The CPU speed was reduced by 900 MHz during single threaded benchmarks. The vast majority of customers will never know why their expensive CPU is not running up to spec.

 

[The red spirit]

The Intel documentation shows all of the package C states that are available but there are a lot of issues with poorly written drivers. The package power C states rarely work as advertised.

True, my i5 10400F can go into core C7 state, but only package C2 state. But to be honest, it might be Windows with 100 background tasks constantly waking up CPU. For proper C state testing I would need some really bare OS.

With Haswell CPUs, I think only the low power 15W U series support package C10. My 4700MQ mobile CPU only supports package C6. I believe package C7 was deliberately disabled to improve stability. There were a few stability issues during the early days of package C states so I think some manufacturers got in the habit of disabling these rather than waste time trying to get them to work reliably.

i7 4770K had all C states available if motherboard could handle them.

The 8th to 10th Gen mobile H series CPUs all support package C8 but this is rarely used. Laptops are shipped and no one seems to care if the package C states are working correctly or not. Review sites never check so no one is aware of this problem. I recently saw a couple of pics of 11th Gen CPUs that were finally using package C10. It has only taken 7 years for manufacturers and Microsoft to start looking into these issues.

I was helping a user earlier this week with his powerful 10870H laptop. Someone at Acer thought it would be a good idea to disable ALL of the C states. Not just the package C states but they released an update that disabled all of the core C states too. This bad idea will prevent Intel Turbo Boost from functioning correctly. The CPU speed was reduced by 900 MHz during single threaded benchmarks. The vast majority of customers will never know why their expensive CPU is not running up to spec.

That's a bad idea, but also not. Sure, you lose CPU speed, but C states seem to affect SSD speed dramatically. Some people at OCN has reported even 70% speed reduction in 4k files reads and writes with C states on. Obviously CPU speed matters, but C states aren't exactly a great solution for maximum performance. The real solution would be to raise PL values instead. I personally see no need to have anything past C1E enabled on my computer and even disabling all C states (except C1 in hidden Windows settings) isn't exactly bad. It mostly matters for laptop users, but one has to remember that C state power savings always come at a cost of performance. It may be some additional delay or loss of SSD speed, but no matter how small performance loss is, it's still a loss of performance.

Thread, where people reported dramatic reductions of SSD speed from C states:

do you have intel c state disabled or enabled?

i don't know how i feel about intel c-state, im just trying to get a consensus of how many people actually have this feature enabled

www.overclock.net

C states actually save the most power at low bursty loads. I may have only saved a few watts at complete idle, but while web browsing I noticed double digit savings. That makes a lot of sense as CPU can then manage which cores to turn on and to what state better, meanwhile at idle you only have a chance to decide how much core should be shut down.

 

[lifer16]

My desktop 10850K had this same problem. Installing the Intel IDE / ATA driver allowed me to finally use package C3.

View attachment 201016

It could be any driver on your computer preventing this. Maybe the Nvidia GPU driver is deliberately blocking package C3. If you have not seen package C3 in over a year then it is going to be very difficult to get this working again. I do not think it would be a good idea installing year old drivers trying to solve this problem.

For myself, getting package C3 working created more problems than it solved. When package C3 is enabled, I get random and continuous static noises through my speakers when listening to anything. I thought I was going to have to RMA my motherboard or else buy an external sound card. It was horrible. I used ThrottleStop to disable package C3 and now the sound is crystal clear. The change happens instantly and is repeatable. Now I leave package C3 disabled.

The difference in power consumption between package C2 and package C3 is minimal.

I see, I was hoping to see some improvement in power draw but I guess c2 hasn't brought me any issues, just wanted to see how if the 8950hk can reach c states beyond c3

 

[unclewebb]

i7 4770K had all C states available if motherboard could handle them.

The BIOS might have had an option to enable all of the C states but that does mean that all of the C states actually worked.

4th Gen Datasheet Volume 1

Datasheets and Specification Updates

Collection of Datasheets and Specification Updates for Intel products.

www.intel.com

Package C7 State
Note: C7 state may not be available on all SKUs.

Package C6 state is the deepest C-state supported on discrete graphics systems with PCI Express Graphics (PEG).

It mostly matters for laptop users

That is true. The person who started this thread has a laptop so he is probably trying to get package C3 working to improve battery run time a hair. If you have a desktop computer or if your laptop is plugged in, 1 or 2 Watts one way or the other does not make any real world difference. It would probably be more productive to eliminate as many useless background tasks as possible.

C states aren't exactly a great solution for maximum performance

The thread you posted from overclock.net is almost 7 years old so I did some quick AS SSD testing to see if these results are still valid. They are. To minimize SSD access latency time and to maximize SSD performance, you are correct, it is best to disable the C states. The difference in power consumption with only C1E enabled compared to having all of the C states enabled is minimal. If you also disable C1E so only C0 and C1 are available, power consumption will go up significantly without much change in performance.

Here is an AS SSD comparison.
Core C3 / C6 / C7 and Package C3 enabled.

Core and Package C States Disabled. Only C1E is enabled.

Big change in 4K read and especially 4K write performance.
This is probably due to the much improved access times.

Some interesting numbers but not really relevant to the original question. I quit.

 

[The red spirit]

That is true. The person who started this thread has a laptop so he is probably trying to get package C3 working to improve battery run time a hair. If you have a desktop computer or if your laptop is plugged in, 1 or 2 Watts one way or the other does not make any real world difference. It would probably be more productive to eliminate as many useless background tasks as possible.

Well, OP can always tweak hidden power plan settings and those can help to extend battery life.

The thread you posted from overclock.net is almost 7 years old so I did some quick AS SSD testing to see if these results are still valid. They are. To minimize SSD access latency time and to maximize SSD performance, you are correct, it is best to disable the C states.

Holy shit, for you difference isn't even in percents but in times. You probably can feel it in system responsiveness as well.

The difference in power consumption with only C1E enabled compared to having all of the C states enabled is minimal. If you also disable C1E so only C0 and C1 are available, power consumption will go up significantly without much change in performance.

Some people tested SSD performance with C1E only and it only lost 16% of 4K speed. C1E saves 8 watts for me, so it's pretty good. It might be due to the fact that computer uses C1 state anyway, so it may as well lower voltage too. It works really well. Still, the biggest power saving feature is Intel Speedshift (or EIST if it's an older chip or Speedstep if it's an ancient chip)

Some interesting numbers but not really relevant to the original question.

Yeah I know. It just seems that many people aren't aware of dramatic performance reduction to SSDs induced by C states. There's a huge performance cost to save few watts, imo it's absolutely not worth it and maybe even on laptop it's not worth it. Small file performance and access time improvements are defining reasons why SSDs beat hard drives and why SSDs are so fast even on ancient interfaces like IDE or SATA 1.5Gbps. To neuter it is basically as good as turning your SSD into spinning rust. On top of that, C states seem to break some older games and make them a stuttery mess. I noticed that in UT2004 and in Colin McRae Rally 2005. CPU in those games gets confused and thinks that they are background tasks as they aren't demanding and put CPU core that processes game into C state. Thus user ends up with bad experience and may even think that their new computer is a slow pos that can't even run old games properly. For all I care, it seems that having C states on is almost never truly worth it and power savings are small. On some AMD chips, C6 state made them really sluggish in everyday use. C states are just poor technology.