Power settings & CPU Throttling

[ltdan81]

I was having very frequent game stopping lag when I dock or leave stations, or moving the ship after setting still for a few moments.

Once I recognized the pattern I took a look at my power options and they were set to balanced... I know I've changed this before, but I think it gets reset sometimes with windows updates.

I switched to maximum performance and made sure that all options were set correctly and it has given the game a much needed boost!

This is not a fix all as I still have stuttering and occasional lag down moments, but it's a start.

This tells me that the game is missing CPU instructions to keep the processors throttled up.

[KlintusFang]

There are no instructions a game (or any other program) can issue to "keep the processor's throttled up". That's not how throttling works. You simply didn't have the OS configured for max performance. There is nothing the application can do about that.

[ziporama]

This is probably more applicable to mobile devices that tend to come factory configured with very aggressive power saving states enabled. Some BIOSes let you turn off some of these thus theoretically ensuring better performance. This incurs increased power usage, thus shorter battery life, and your mileage may vary.

You can look at disabling speed step for example. Such settings are in the BIOS and won't be in the power management screens as they are hardware settings.

In my experience, laptops benefit a lot more from this for game playing that desktops do.

Z.

Z.

[Sam L.R. Griffiths]

This is probably more applicable to mobile devices that tend to come factory configured with very aggressive power saving states enabled.

This used to be the case but not any more really... modern desktop CPUs implement Cool 'n' Quiet/SpeedStep and have done for several years now. In addition they implement a form of factory endorsed on-demand over clocking technology (e.g. AMD Turbo Boost).

You can look at disabling speed step for example. Such settings are in the BIOS and won't be in the power management screens as they are hardware settings.

Power saving and clock boosting technologies can be influenced by the OS. Putting the OS into Maximum Performance mode locks the CPU Cores into nominal maximum clock speed and prevents technologies such as Speed Step from kicking in.

On my FX-8350 as I write this post the CPU is currently idling at ~1.4GHz with an occasional pip up to ~2.2GHz and even rarer pip up to >4 GHz. This is because the OS is letting the CPU idle when it can since it is set to Balanced mode.

Now I switch the OS to Maximum Performance mode and the CPU is kept locked at 4.1GHz (half way between the 4.0GHz to 4.2GHz that the CPU is rated at - 4.2GHz being the maximum Turbo Boost speed).

I have had similar behaviour with my old Phenom II X6 1055T but the Turbo Boost technology in that processor was so broken that I had to switch off 3 of the 6 cores (via the BIOS) in order to ensure that I got the most stable performance out of the CPU.

On each of our individual systems (Desktop or Laptop) some BIOS settings may need to be tweaked if there are issues with the technologies implemented in our CPUs but setting the OS power management settings Maximum Performance can possibly mitigate most of the issues.

For Example: Some older implementations of Hyper Threading for instance had to be disabled to ensure you got reliable performance out of the CPU (Intel appear to have resolved this with the implementation of in the i3/i5/i7 series processors though).

For Example: AMD TurboBoost v1 processors can benefit from having half the cores disabled.

The only caution about the Maximum Performance setting is ensure that the CPU has sufficient cooling capacity otherwise you could suffer from system stability issues.

[BigBANGtheory]

I allow my i7 4770k to use speed step, but using a program called CPU-Z I can see in real-time the clock speed of the processor as the multiplier is changed by the system.

At idle it tends to run at about 800MHz
Under load it is 4800MHz (or 4.8GHz)

If I watch CPU-Z on a 2nd monitor when X Rebirth is running it maintains a constant max clock speed as you would expect. The game unfortunately remains very unplayable for me atm.

So "This tells me that the game is missing CPU instructions to keep the processors throttled up. " I would dispute.

If you suspect your CPU is effected by Power Management, Thermal throttling etc load CPU-Z and see what it is up to in real-time. FYI Intel Turbo Boost is only applied to the first core, not all cores. Speed step however is applied to all cores and depending on your system can change these setting from the system board BIOS or windows power management. Check first though if its not a problem then don't go changing things.

[AnarkistUK]

Something I forgot to do when I last re-installed Win 7 was to make sure I unparked the cores on my CPU, doing this and setting V-Sync to Adaptive (Half Refresh Rate) in the Nvidia control panel has smoothed things out a lot with regards to stutter.

[ziporama]

...

So "This tells me that the game is missing CPU instructions to keep the processors throttled up. " I would dispute.

....

Agreed. From what I can see from MSI Afterburner's logs is that the game is actually not well served by very high speed video cards because the video seems to move past the CPU's ability to feed it. What I'm finding in that regards is that the experience is actually smoother at higher resolutions / higher graphics settings (stresses the GPU more) than at lower res. So, if I set my resolution to full HD and crank up AA and other quality settings, I actually get a better experience, keeping everything else equal, than tuning things down.


Unless this has changed, there can only be one rendering (UI) thread anyway feeding the GPU so I suspect the bottleneck is the first CPU core regardless of how many you have. Also, this is a DX9 title so it probably does a lot more pre-processing on the CPU than the GPU compared to what DX11 can do for example. DX11 can move much more stuff to the GPU to handle.

My theory anyway.

[BigBANGtheory]

...

So "This tells me that the game is missing CPU instructions to keep the processors throttled up. " I would dispute.

....

Agreed. From what I can see from MSI Afterburner's logs is that the game is actually not well served by very high speed video cards because the video seems to move past the CPU's ability to feed it. What I'm finding in that regards is that the experience is actually smoother at higher resolutions / higher graphics settings (stresses the GPU more) than at lower res. So, if I set my resolution to full HD and crank up AA and other quality settings, I actually get a better experience, keeping everything else equal, than tuning things down.

You know what that does actually help.

So at x4 AA I am seeing a much smoother frame rate at the cost of lower average frame rates, which makes the game much more playable now.