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Can anybody tell me what exactly the hard drive cache affects? I'm probably going to buy an OWC elite, and am trying to decide if I should get a 8 or 2 MB cache drive.

I'm using a digi002 on a 667MHz Powerbook and Digital Performer 3. I keep getting an error when I move the latency up to an acceptable level, and I'm unsure if it's because of my internal hard drive on my laptop, or if it's something else...slightly more sinister. I'm hoping that recording to an external drive will destroy these errors. BTW, it gives me these errors when I have tracks record enabled, but no actually recording. Is this the hard drive cache, or disk speed, or does it have nothing to do with that.

Does anybody have any insight please?
Thanks! :confused:

Comments

Nate Tschetter Wed, 07/23/2003 - 17:25

Howdy

OK, there are two different things here: hard disk cache and a buffer setting. Hard disk cache (and I might be wrong here) is actual memory on the drive that acts as a buffer between the physical disk and the bus into the computer. I believe that a larger disk cache (again, I could be wrong) is better.

Buffer settings are similar in that its an intermediary place between memory and disk. With ASIO drivers, lower buffer settings reduce input to output latency at the expense of track count. The opposite is true of higher buffer settings.

So, it sounds like you're just running out of computing power. When you record enable tracks, the buffer is "activated" so that indeed could be why you get "maxed out" even if you aren't recording.

You'll have to find some sort of happy medium between the track count and latency setting.

Hopefully, someone will correct my erroneous statements.

anonymous Wed, 07/23/2003 - 18:49

Hi Jay,

I have DP3 and Digi001 (G4 733 Quicksilver) and had similar problems. They were solved once I installed and recorded to a second internal drive. I also installed more memory based on recommendations that the computer would run better with more memory even though technically I shouldn't have needed it. I now have a gig plus. Much improved performance and no error messages !!!! I mostly attribute this to the 2nd drive. I couldn't say how much the extra memory helped. I am positive the 2nd drive helped. That's because the boot drive is having to deal with the program, the performance, the memory, the DP files and everything else. In DP, your performance monitor (Windows>Performance Monitor, I believe) is probably showing that you are maxed out. The 2nd drive should fix that. If you can get a 10,000rpm SCSI drive that would be the best. They aren't cheap though, close to $1000. I got a second internal drive just like the one that came with the computer. It works just fine. I believe it is an ATA 72,500rpm drive. It was somewhere arond $250. Once you do that you should be able to bring your buffer size back down so you don't have the latency issue.

Good luck.

Cheers,
Sioux

gdoubleyou Thu, 07/24/2003 - 06:08

The default disk cache in OS 9.x is a little bit over 8Mb,
on older machines, and earlier technolgy IDE drives 512k system disk cache seems to work better.

Pops and clicks can result when an audio app requests audio and the disk cache is not full.

Smaller disk cache makes your drive work harder taking lots of smaller accesses, instead of one long access. It also ensures that the cache will be full, and data will be available for processing.

Newer G4's have faster IDE buses, newer drives may have an on board disk cache, that makes the setting a moot point. Western Digatal Special Edition drives have an onboard cache of 8Mb.

Go for the 8Mb, experiment with disc cache size in OS9, it's not an issue in OSX.
:D

Guest Thu, 07/24/2003 - 09:42

Thanks everyone for the comments, that was all very helpful. I think I'm going to just buy an external firewire drive with 8MB of cache and see how it goes. It sounds like it should make a difference.

As for ram, I've 768 running Digital Performer in OS 9.2. I have allocated 512 megs to DP, so that better not be the problem!! I actually just installed that RAM a week ago, and it didn't offer any performance enhancement with regard to my ability to have tracks in record mode.

I'll post a follow up when my OWC arrives to let everyone know how it went.

Thanks!

anonymous Thu, 07/24/2003 - 16:32

You have way too much allocated to DP. I have 1.25 gig of memory. MOTU had me take my memory down to 200 saying that I had WAY to much at 300. You need to read the Getting Started Guide regarding that. Page 35 Adjusting memory Allocation. I think you don't don't have enough memory for MAS.

"With MAS, your approach should be as follows: instead of assigning as much RAM as possible to DP, try to asign only a comfortable amount fo RAM to DP (so that there are at least a few megabytes free in DP's Performance Monitor). This frees up as much RAM as possible for MAS, give you as many audio voices as possible on your MacIntosh."

Sioux

anonymous Mon, 07/28/2003 - 07:16

Exactly my thoughts Sioux! I was curious if Jay had enough allocated to his playback engine. Pro Tools is the same way. You can allocate every byte of RAM you have to Pro Tools and it will still choke if DAE is limited.
I don't think a harddrive is the fix, but it will be nice to get the extra room!
Good luck! :c:

anonymous Mon, 07/28/2003 - 17:53

Hi Daniel,

I do think another drive will be part of the fix...it will help the performace. However, I'm not sure if the firewire drive will do it. The memory is another issue altogether. You may be right though. I suspect it was a combination of several things. I guess we'll see. I wish him luck with it all. At least it's fixable! That's always a good thing! :)

Sioux

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