Ableton Forum

This post is addressed to anyone who can help using the Realtek High Definition Drivers in XP or who uses a Santa Rosa MBP with Live in Xp via bootcamp.

i have just upgraded my original 2.0gh core duo to a new 2.4gh santa rosa Macbook Pro. Although the performance from Live in OSX has improved... I cannot get the same performance from this machine as my last.

I predominately used XP via bootcamp on my last machine as I was able to achieve stable performance at a buffer of 64 samples using the internal sound card with asio4all (freeware). This was much faster than the minimum 256 samples I was getting from OSX and still faster than the ~100 I'm getting now.

Now that I have upgraded to a Santa Rosa MBP, performance in XP is horrible. When I press on the test tone in live, the performance meter jumps straight to 50% (irrespective of the sample rate) and I cannot get it below 800 samples without the audio glitching (even when using asio4all).

On the XP side the most noticeable change to the MBP is the sound card driver. The Intel HDA (sound card) was previously driven by Sigmatel but now it has changed to Realtek. I have tried to force the MBP to install the old driver but the device will not function correctly with it.

I am mostly interested in the difference between Sigmatel High Definition Audio and Realtek High Definition Audio drivers. I'm lead to believe there is a problem with Realtek's drivers from reading the following post at the asio4all forum:

http://mtippach.proboards40.com/index.c ... 1117561217

Are there Live users out there getting good performance from Live (i.e. low latency/sample rate) using the Realtek HDA driver in XP? Has anyone got it working at 64 samples with asio4all?

Has anyone successfully replaced the realtek driver with a better working alternative.

Obviously I could get around this by using an external interface but I don't think I should have too. Also, I am well aware of the benefits of both operating systems and am not looking for a mac v windows debate.

Thanks in advance for any info you can give me.

I found the exact same thing - my old Macbook (non-Pro) was amazingly agile with the internal soundcard on ASIO4ALL... I upgrade to a 2.4 Santa Rosa and *bam* I can't use anything under 1024 samples, either on MME or ASIO4ALL...

I think these "HD" soundcards themselves are crap, not just the drivers... judging from the ASIO4ALL forums, people with laptops of almost every brand are having major difficulties with *any* "HD" internal audio chipset, regardless of whether it's Realtek or Sigmatel, and anyone using a non-"HD" internal chipset (e.g. Macbook users) never seems to have any problems...

Thanks Vance. Glad to know I'm not alone,

I'm not yet prepared to blame this on the HD sound card for a couple of reasons. Firstly, this sound card runs at very low latency using OSX. Secondly, my last MBP also had an Intel HD card and had great performance in XP.

Previous macbooks listed the audio card in device manager (XP) as Sigmatel and there was Sigmatel software in the control panel. Now both of these have been replaced by Realtek and I have much less control over the audio settings... and horrible performance.

Does anyone know the difference between Sigmatel and Realtek? Do they even make hardware? Why would Apple chose one over the other?

The 'HD audio bus' is part of the Intel chipset - you still need a codec chip to get any sounds in and out. Most notebooks have used Sigmatel or Realtek chips for years. Your problem sounds like a crappy Realtek driver, so you should try the latest driver from the Realtek site:

http://www.realtek.com.tw/downloads/dow ... Down=false


(p.s. as ASUS makes these things, it's actually them that chooses the chips - it's pretty random what they use, my ASUS notebook uses an Analog Devices HD codec)

Thanks. I have already installed the latest drivers but don't get any increased performance.

Am I wrong in blaming this on realtek drivers? Do these drivers run well on other machines?