High Buffer Size Needed

dpv

New member
Hello everyone,

Here is my issue, I've recently acquired a iMAC G5, with the following characteristics:

Mac OS X Tiger 10.4.3
1.8 GHz PowerPC G5
1.5 Go DDR SDRAM

I know it's old, but still, its only purpose is audio production and it won't be polluted by anything else. Indeed, the first things I've done were formatting the Disk and installing REAPER v4.32/PPC that I use with a TASCAM FireOne audio interface.

On my first session to test how things were running, I've recorded 2 guitar tracks. Everything went well with low latency, and then I've added 2 buses tracks (one for reverb and one for delay). Both guitar tracks are sent to the reverb (ReaVerb) and one is sent to the delay (ReaDelay). During playback, "crackles" and "drops" are heard until I increase the buffer size higher than 1028 (that then puts the latency around 25/30ms)!
When I run the playback at 128spls (Buffer Size), full of drops, the CPU Usage shows ~55%, shouldn't it be way higher for the bad quality I get?

So I have a few questions:

Could this be linked to anything else than the processor (or RAM)?
Could using ASIO driver instead of CoreAudio change anything?
Is there anywhere I could get a Reaper Demo Session to try playback on a normal sized session?
Is there an older Reaper Version available, on which things could run smoother?
Is that because the Mac is getting physically old? Knowing that back in 2006/2007 my actual configuration was around the best possible (I guess there already were home studist at that time ^^

Anyway, thanks for you answers
 
Hello everyone,

Here is my issue, I've recently acquired a iMAC G5, with the following characteristics:

Mac OS X Tiger 10.4.3
1.8 GHz PowerPC G5
1.5 Go DDR SDRAM

I know it's old, but still, its only purpose is audio production and it won't be polluted by anything else. Indeed, the first things I've done were formatting the Disk and installing REAPER v4.32/PPC that I use with a TASCAM FireOne audio interface.

On my first session to test how things were running, I've recorded 2 guitar tracks. Everything went well with low latency, and then I've added 2 buses tracks (one for reverb and one for delay). Both guitar tracks are sent to the reverb (ReaVerb) and one is sent to the delay (ReaDelay). During playback, "crackles" and "drops" are heard until I increase the buffer size higher than 1028 (that then puts the latency around 25/30ms)!
When I run the playback at 128spls (Buffer Size), full of drops, the CPU Usage shows ~55%, shouldn't it be way higher for the bad quality I get?

So I have a few questions:

Could this be linked to anything else than the processor (or RAM)?
Could using ASIO driver instead of CoreAudio change anything?
Is there anywhere I could get a Reaper Demo Session to try playback on a normal sized session?
Is there an older Reaper Version available, on which things could run smoother?
Is that because the Mac is getting physically old? Knowing that back in 2006/2007 my actual configuration was around the best possible (I guess there already were home studist at that time ^^

Anyway, thanks for you answers

ReaVerb is a convolution reverb plugin and is quite intensive - that might be causing your issue. Probable options are: record at one latency setting, then up the buffer size when mixing; upgrade your Mac; use less intensive plugins.

Even with high latency, you can record just fine as Reaper will automagically align everything up - just play along as you hear it.
 
Hi there,

The first things to do would be to update the OS to the maximum within 10.4. I think 10.4.11? Can't remember.

Hit the Tascam website and make sure that you are using the most up to date driver that's available for your OS.
Don't get anything for leopard or whatever. It' wont be better.

If you still have grief it wouldn't be a bad idea to rule out hardware issues.
Do you have an apple hardware test CD?
If not, at least download this and let it run a good while.
It'll test your RAM.


It's hard to say but it could just be how things are. Maybe the DAW + plugs are just too intensive for your machine?
I'll have a google for older versions later.
 
Hi,

Thanks for the quick answers. I'm still wondering why I get these results for a ~40/50% CPU usage. Shouldn't things start to crack somewhere over 80% CPU Usage if it was linked with the processor or the RAM?

Anyway I'll try this OS update and memory check (coz' it seems I already have the latest drivers for the FireOne). I'm not sure I have an apple hardware test CD but I do have the installation CD for sure, is that what you're talking about?

I'll give more news later concerning the results I get.

Thank you again for your help
 
Anyway I'll try this OS update and memory check (coz' it seems I already have the latest drivers for the FireOne).
Cool, do that. They release the .4,.5,.6 updates to address isues so it's definitely worth doing.

You have the latest drivers, or the latest drivers for your OS? That's important.

I'm not sure I have an apple hardware test CD but I do have the installation CD for sure, is that what you're talking about?
Yeah, If I remember correctly it's built into that disc. You hold down a key at boot to load it up.
To be honest you'd be better googling that because I'm not even sure if apple did that in PPC days. I'm a newcomer. :p




If it was a ram issue then CPU usage wouldn't necessarily peak out.

Just for arguments sake, if the CPU was overheating if wouldn't show high % use....It would just crap out.

In fact, a hoover never goes a miss on an old computer. ;)
 
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