Audio and Sample From The SAME DRIVE Can Be Done With An SSD.

[epu]

Just confirming this. Using a laptop with two drives, you can run samples and audio from the same drive using an SSD with fast r/w speeds. My SSD does about 100 MB r/w and I am running 32 audio tracks with at least four instances of Kontakt which uses heavy streaming.

[daeron80]

If I'm doing the math right, 100 MB/s transfer rates should allow 728 tracks of 24 bit, 48 kHz audio. That ought to about do it. Of course, there's the connection rate, too. I suppose with a disc that fast, the bottleneck would be the connection between it and the computer.

[epu]

I wish Pro-Tools LE could do that many tracks. Of course, I'm able to do as much as I am currently, which is more than enough for me. Saves me from having to buy another internal drive. Now, if they only made Expresscard SSDs larger than 16GB (w/+100MB r/w speeds).

[daeron80]

On a card? Interesting. I have no idea what sustained transfer rates are for the Expresscard interface. Never heard of anyone running sessions on it. Let us know how it works for you.

I thought you were talking about something like this.

[daeron80]

Well, see, I'm confused now. Because a Western Digital Caviar Black drive - the old fashioned spinning disk kind - is said to have a sustained data transfer rate of 106 MB/s. In theory, that should deliver 771 simultaneous tracks of 24/48. But we all know from experience that when you start pushing any 7200 RPM platter much past 30-some tracks, even if it's connected via SATA, PT will begin to choke and say it can't get data from the disk fast enough. Why is that? SATA is a 3 GB/s pipe. Why can't we get the stated performance, I wonder?

[Dism]

Originally Posted by daeron80

Well, see, I'm confused now. Because a Western Digital Caviar Black drive - the old fashioned spinning disk kind - is said to have a sustained data transfer rate of 106 MB/s. In theory, that should deliver 771 simultaneous tracks of 24/48. But we all know from experience that when you start pushing any 7200 RPM platter much past 30-some tracks, even if it's connected via SATA, PT will begin to choke and say it can't get data from the disk fast enough. Why is that? SATA is a 3 GB/s pipe. Why can't we get the stated performance, I wonder?

That 106mb/s is combined, first off. All of the benchmarks I've seen confirm a 7200rpm drive as having around a 45mb/s write speed. I'm not sure how one could expect to deliver 700+ tracks to a single drive at that rate... So these "theories" sound a little sketchy to me.

At any rate... I've had a session with 60+ tracks on a 5400 drive run without giving me disk underflow errors, so you shouldn't be getting any disk errors at 30 tracks unless you are doing something unsupported, or running more than just sessions from that disk.

[daeron80]

Interesting. You do know there's a difference between Mb and MB, right? The latter is 8 times as much. The 106 MB/s is Western Digital's sustained transfer rate spec, and is backed up by 3rd party benchmarks. When I say "in theory" I'm just doing the math. One mono track of 24 bit 48 kHz audio is 24*48000 bits/s = 3*48000 Bytes/s = 144000. That's 144000/1024^2 = 0.13732910156 MB/s. If a disk can truly sustain 106 MB/s, it can deliver 106/0.13732910156 tracks, or 771 rounded down. If they could really do that, we'd have no trouble running 128 tracks plus more samplers than any available CPU could handle. We know that people who run sampler data from their session disc regularly run into trouble, showing that the spec doesn't mean what it appears to.

It's been a while since I've had a really large session at home. I'll have to give Reaper a run and see how many I can pull off of my Caviar Black. Since I'm still on 7, I can only do 32 mono tracks at once in PT, anyway.

[netnoggin]

Originally Posted by Dism

That 106mb/s is combined, first off. All of the benchmarks I've seen confirm a 7200rpm drive as having around a 45mb/s write speed. I'm not sure how one could expect to deliver 700+ tracks to a single drive at that rate... So these "theories" sound a little sketchy to me.

At any rate... I've had a session with 60+ tracks on a 5400 drive run without giving me disk underflow errors, so you shouldn't be getting any disk errors at 30 tracks unless you are doing something unsupported, or running more than just sessions from that disk.

My WD Black performs in the 70mb/s range according to HDTach. But anyway, focusing on sustained transfer rates is the problem. A typical DAW doesn't write or read to the disk in "sustained transfers", it does it in small segments. Watch your drive light sometime. And in-between those moments, the head may get repositioned, so you have to calculate in seek times as well. Add to that your interrupt acquisition time and other hardware-related delays that may be happening on your motherboard, and you have significant delays that skew your calculation. So a track count based only on sustained transfer rates is optimistic and not exactly real-world.

That said, I agree - 30 tracks is a little low for today's hardware. I can do better than that pretty much anytime, with a Q6600/P5K multiple WD Black setup.

[sunburst79]

PT is a non linear editor. The files can be anywhere on the drive. Theres a lot more going on than just writing .wav files.

[Dism]

Originally Posted by daeron80

Interesting. You do know there's a difference between Mb and MB, right? The latter is 8 times as much. The 106 MB/s is Western Digital's sustained transfer rate spec, and is backed up by 3rd party benchmarks. It's been a while since I've had a really large session at home. I'll have to give Reaper a run and see how many I can pull off of my Caviar Black. Since I'm still on 7, I can only do 32 mono tracks at once in PT, anyway.

I would like to see these benchmarks, honestly. I've seen a few for several different 7200rpm models of different brands and they all tend to avg out around 40-50mb/s WRITE speed. Typically, the spec given to you by the manufacturer is the combined read/write speed so to make it sound a lot faster.

And yes, I do know the difference between a bit and a byte.

My largest LE session is 74 tracks, mostly mono, with a couple stereo sums, and the only errors I ever saw were due to CPU use because of the 90+ plugins I have running. Even those were few and far between.