[ardour-users] Intel EM64T and Ardour+VST

[Steven Chamberlain]

Andrew Johnston wrote:
>I am currently running a gentoo 64 bit install on my AMD64 dual core
>3800+. I do agree with the replies above, however I have chosen to
>stay with 64 bit after trying to redo my gentoo install with 32bit,
>and having huge problems.

Have you tried making a 32-bit chroot? On Debian this was quite easy for
me. In /var/chroot I have a fairly minimal 32-bit Debian install in
which I can compile and run software that only works in a 32-bit
userland. But I don't believe I've ever had problems running ardour or
ardour2 under a 64-bit userland -- except VST, because I couldn't get
WINE to compile in 64-bit. Perhaps this has changed since then, or if
not, it will no doubt work inside the 32-bit chroot. But with the huge
amount of progress Linux audio is making these days, I can quite easily
live without VST.

>The only problems I ever encounter is with JACK running my kernel
>with SMP support (a well known but as of yet unfixed bug).  I also
>find the system a little more unstable as a whole

Snap!
I've been having a lot of these kind of problems ever since I got my
Athlon dual-core, but I didn't realise it was affecting other people.
I had to go back to 2.6.16-rt29 to find some stability with SMP enabled,
but I still battle with high latencies.

>On 8/24/06, George Chan <george at goodmusic.ca> wrote:
>>Most video codecs (like for mplayer, etc.) are available for 32bit
>>ONLY.

Again, I managed this with a 32-bit chroot. I'm not familiar with Gentoo
but for Debian I found this guide helpful:
   http://www.debian-administration.org/articles/356
(though there is a mistake in the guide: '-arch' should be '--arch')

>>Also, I was never able to get a low latency kernel working in
>>64bit.  I tried something like 25(!) different configurations.
>>Every single one hung at boot up.  On my single CPU, 32bit machine,
>>the low latency kernel worked fine on my first try.

Did you try a 64-bit, uniprocessor kernel? I had no problems with 64-bit
rt- patched kernels until I got an Athlon X2 and enabled SMP. I think
SMP kernels without the rt- patch were also stable.

>>Also, there were intermittent problems with my video files playing
>>back at double normal speeds.  Never was able to fix that one.

Timer problems seem to be widely reported with Athlon dual-cores, though
it's never affected me; apparently things can run at double speed (even
the keyboard), or the system clock can speed up under higher CPU load.
Your problem might be somehow related to that.

Regards,
-- 
Steven Chamberlain
steven at pyro.eu.org