Get rid of clicks/pops/dropouts (C1E, C3, C6/C7, EIST)


No, those aren’t Cubase acronyms you see in the subject. More on this later…

Like many others I’ve wrestled with clicks, pops, and dropouts in general. To fix these problems, in some cases it’s a matter of swapping out your video card or updating to the latest drivers (in some cases that’s what causes the problem) and maybe tweaking your ‘visual’ settings, registry, etc. Usually, there’s no magic bullet, however.

I own a GIGABYTE GA-Z97X-UD5H, which comes with two classic PCI slots, one of which is in use by my old-school RME HDSP 9652 PCI (slaved off a newer RayDAT). It works perfectly. I use the built in Intel graphics card to save a PCIe slot. I also own two UAD cards: a Quad and Octo-Quad

Anyhow, here’s how I got rid of my audio card problems:

Disable all of the following in the BIOS:

CPU Enhanced Halt (C1E)
C3 State Support
C6/C7 State Support
CPU EIST Function (this is SpeedStep)

After you do this, see if you still have problems. If not, you can begin to re-enable those options starting from the top-down. For me, here’s how it works:

All enabled: I get static, crackles, dropouts, etc. SpeedStep is the worst culprit. Not always, but randomly every 1/2 minutes.

ENABLED - CPU Enhanced Halt (C1E)
ENABLED - C3 State Support
ENABLED - C6/C7 State Support
DISABLED - CPU EIST Function (this is SpeedStep)

The system is much more tolerable, but I will still get random dropouts and very occasionally some crackles.

ENABLED - CPU Enhanced Halt (C1E)
DISABLED - C3 State Support
DISABLED - C6/C7 State Support
DISABLED - CPU EIST Function (this is SpeedStep)

My system runs perfectly at 32 sample buffers (0.75 ms @ 44.1)

You will want C1E on because it really helps in reducing the CPU temperature. If you must disable C1E for recording still (due to crackles, etc), then you can use RealTemp ( to disable it within Windows when needed before running Cubase.

Note 1: if you want to enable/disable C1E through RealTemp automatically, I suppose you can do this with the powerful macro language AutoIT (I’ve used it, it’s insanely good).

Note 2: maybe there are other apps that can enable C1E in Windows, you have to search for them.

Note 3: RealTemp let’s you also disable SpeedStep (EIST), but I had inconsistent results. You might want to try it though. I believe if it had to do with the fact that I had disabled C3/C6 in the bios.

Note 4: My understanding is that C3/C6-7 are deeper sleep states, which depend on C1E. So for C3 to work, you need C1E enabled, for C6-7 to work, you need C1E and C3 enabled all the way possibly too SpeedStep (EIST). With this in mind, it might be that enabling SpeedStep automatically enables all the C states. Not too sure and it might depend on the BIOS. If someone has a better understanding of this, please let us know.