View Full Version : Sound Stuttering - ATA in older Macs

01-13-2002, 09:41 AM
I have been researching all morning whether to get an ATA and an IDE drive. After reading through the Gurus comments and a lengthy collection of readers comments on XLR8yourmac.com, I am left with a major question. Apparently the ATA IDE cards seem to cause audio drop out (stuttering) on 90% of older Macs (73/75/76).

http://www.macgurus.com/ubb/confused.gif The commentator could not determine the rhyme and the reason for the sound stuttering problem. I was wondering if getting a Granite cable from Gurus might help? They seem to think it the result of the speed of the ATA but I am wondering if better cabling might be the cure. I also need a CD player (posted elsewhere) and I read in one forum conversation that keeping a SCCI CD would still not be any slower or faster than an IDE CD, so that may not be my concern for getting the ATA over the "better" and much more expensive, Ultra SCCI set ups.

But that assumes relative parity in quality. As in, going ATA should not be at the expense of not being able to make a movie or to record mp3s (both reasonable goals).

And so, looking at the cheapest ATA66 (with good reviews) and going up to one with Soft raid and stripping, and wanting to put in system 10 at some point, what is the truth of these ATA66 or ATA100 cards?

Are all ATA cards now compatible with system 10? Are some of them, not? Is the VST compatible with system 10? Is raid compatible with system 10? Does the ATA100 eliminate the audio drop out problem (stuttering) that happens so often with the ATA66? What are others experiences in stuttering - or not, in older Macs? Inquiring minds want to know?


01-13-2002, 12:15 PM
Hi levelbest,
You mention ATA and Softraid in the same sentenece. Software RAID doesn't accomplish anything with ATA drives for some reason. Hardware RAID does. In fact an ATA hardware RAID card will DOUBLE your performance over a single drive. The price of an Acard ATA133 Hardware RAID card is around $150, it's also fully OSX compatible. That is the way to go.

ATA100 drives are getting cheaper, they will very much increase the performance of your drives over the ATA66 drives that you mention. I don't think anyone is currently manufacturing an ATA66 drive so you would be buying old stock and frequently the same drive manufactured to a slower spec as todays drives.

Acards RAID offering has good cables, I have never heard that better cables solved the stuttering issue. One of the forum members who speaks audio did mention slowing down the burst rate on the drives as a solution, hopefully he will post here as I don't know whether this is a perfect fix or not.

If you are aiming to add a PCI ATA host card and then RAID the drives on it you will not want a CD-Rom on the same bus. Speed is not the issue as you already mentioned. Firewire,USB,SCSI or ATA are all the same in that the bus is much faster than the slowness of the CD-Rom.

One of the Audio folks ought to be able to detail more on this.


01-22-2002, 01:02 PM
Hello, i just happened along and saw "sound stuttering" and since i've experienced this myself, thought i would throw in. I encountered stuttering on a 7500 with powerlogix 220 G3 upgrade, overclocked to 300 mHz, and 256 mb RAM. the drive was a 10000 rpm cheetah with miles2 and although i had the burst rate, at least i think, set to default, i never expected stuttering when i played back mp3 audio. i am playing mp3 audio on a powermac G4 now and there is no stuttering - ATA100 drives i believe. i have concluded that it is more a factor of processor speed and maybe system bus speed than drive speed.

01-22-2002, 01:22 PM
I appreciate your input. This topic fizzled rather quickly and I have not been able to resolve my question. You are saying that you got the stuttering on a fast (miles2) SCCI? Hmmm. Maybe I should just take my chances with the ATA 100. I do read that the ATA drives (from several comments on xlr8yourmac.com) seem to put out a lot less "white" noise than do the higher RPM cheetahs, etc. I have to say, that is a least partially a factor.

But not being able to try out the macs audio and video capabilities, once I finally get hard drive space? That doen't make much sense to me. Surely accelerating these old macs (mine a 7300 and a 7600) wouldn't be at the expense of stuttering sound?

Say it ain't so?



01-22-2002, 09:32 PM
This is very odd. I have learned a great deal from these pages about my 7300 series Mac. The legendary Bam Bam and all... But here is a rather large problem that I never heard about prior to searching the xlr8yourmac.com archives.

I would like to know that this problem will be solved with some choices. But it seems, not. I see this machine being my first test platform for getting 10 eventually. And after I tire of that, it will likely be time for a new Mac. My 2 and my 4 gig drives are at capacity already. And I haven't even started to play with movies or sound files. Just a few Photoshop files.

And so I can get a $50 ata66 card, or I can spend $150 for the ATA100 with a hardware raid. I wonder if it makes sense to get the ATA 100 if they both stutter? Heck, even the well touted Miles stutters. That's a real surprise after hearing it spoken of in such glowing terms around here.

Of course, going cheap is not always the best solution. So maybe the ATA100 is a better upgrade? Sadly, the ripping of tunes and videos etc, with a messed up audio playback and record, seems a waste of a good Mac. So I would hope that the ATA100 and a compatible drive would work? If not, then, functional but cheap.


01-23-2002, 01:08 AM
Here's my experience with ATA-PCI cards. My machine is a late generation 8500 (180 MHz 604e - now G3 upgraded), and I've had 2 ATA-PCI cards in the past: a TurboMax ATA 33 and my present Sonnet Tempo ATA 100. With my TurboMax card, I would get no stuttering when playing MP3's provided I did nothing else at the computer. However, if I turned on virtual memory, my AV stuff worked perfectly fine. With my Sonnet Tempo card, I no longer have to enable virtual memory to eliminate stuttering. I think my situation is more the exception than the rule though.

Both Acard and Sonnet have released software that will slow down their ATA-PCI cards but will eliminate AV stutter. I've not used the software myself as I don't need it, but reports I've read indicate that it works. I don't remember the hit in performance, but I'm thinking that even with the AV-slowing software, the drives were still getting ~10 MB/sec (check xlr8yourmac for the numbers). Just for reference, my 8500 (upgraded to G3/400) can sustain >20 MB/sec using a 7200 RPM 40 GB Maxtor drive (not slowed down).

My understanding of AV stuttering problems is that the controller card (either ATA or SCSI) is running faster than the computer can handle so they need to be slowed down in order to fix the AV issue. Hopefully someone can chime in to either support my claim or educate me on what I've derived from my readings.

01-23-2002, 01:19 AM
Oh, I forgot to mention the OS X compatibility. With my TurboMax ATA 33 card there is no OS X compatibility. However, with my Sonnet Tempo ATA 100 card there is very good compatibility. I can't cold start my computer into the OS X partition of my Tempo-connected hard drive, but I'm using an unsupported Mac (8500) so it might not actually be the card which is the problem here. My understanding is that the Sonnet and Acard's 66's are both OS X upgradeable (although they may need firmware updates) and that both companies' current offerings are all OS X compatible as is some other companies card (Miglia?? are something or other). More often than not, if it works with OS X, it'll be mentioned in the products description. Another thing, I'm not sure if the AV slowing down software is available (or necessary) under OS X - perhaps a quick email to the companies' support staff can answer that.

01-23-2002, 01:51 AM
The Miglia card is identical to the Acard. Acards raid looks the same as the Sonnet although no-one has come out and announced that it's the same.

01-23-2002, 05:54 PM

I have a 7500 with the XLR8 G3 400MHz upgrade, 288 megs RAM, Miles2 + 10k Cheetah, OS 9.1.

The only time I experience any stuttering is opening the Netscape app. while iTunes is playing and it is minimal. After Netscape is open I can surf without any problems/stuttering. I always have Netscape, iTunes, AppleWorks, Eudora at a minimum open.

My friend has a stock PCI G4 350/400? and it stutters the same way as my 7500.