KVR Audio

monsterbeetle · Post by **monsterbeetle** » Fri Aug 20, 2004 2:00 pm

Hi!

I will shortly (hopefully no later than this weekend) move all my DAW on a 1.4 PM w/ centrino laptop.

All my projects are currently stored on a 7200rpm Maxtor IDE drive inside my desktop.

I will turn this drive into a modile drive using an enclosure. However before I buy the enclosure, I need to know which from the USB 2.0 or FW connection can handle my needs:

My projects usually have 16 to 22 tracks of audio at 24/48 (we might want to round that up to 25 tracks). I use close to no midi at all. I'd like to keep the HDD and live audio streams on two separate controllers (logically more chances to get a trouble free low latency performance).

If you tell me the USB can stream 25 24/48 tracks, I'd go for it rather than for Firewire, because my upcoming audio interface will most probably be using the FA-101.

But if you tell me USB cant stream 25 24/48 tracks , then I would rush for a firewire drive and switch to a USB 2.0 interface such as the UA1000.

All these questions because I don't want to spend 30 extra euros for a enclosure that can do both USB 2.0 and FW if either one of these fits my needs.

Thanks guys, I'm waiting for you now!

DevonB · Post by **DevonB** » Fri Aug 20, 2004 2:14 pm

Can you tell me real quick how many megs a minute 24 bit 48khz takes up?

Devon

monsterbeetle · Post by **monsterbeetle** » Fri Aug 20, 2004 2:41 pm

errrr I don't know 32*2*48000*25=76800000 bits per sec, but latency is not only about bandwith, but also about timing, protocol overhead, etc...

Devon, what are you using as live external storage?

DevonB · Post by **DevonB** » Fri Aug 20, 2004 3:03 pm

I'm not, internal only. Keep in mind FireWire has less overhead than USB. I just know that 8 tracks of 44.1k 16 bit is the max you can hope for on USB 1.1 in normal mode. If we know the throughput for 24 bit/48khz, we can do some rough calculations.

If I am right, (and please someone correct me if I'm wrong here) 24 bit and 48khz, should be about 16.5 megs a minute. 25 tracks would yield an approximate thorughput need of 6.875 megs per second. USB2 is supposed to do 60 megs per second. So the USB2 wouldn't necessarily be the bottleneck here. Other things come into play here, like fragmentation, and the like, and USB's overhead....

Short answer, I don't know, but it looks possible at least. I would need to do more google searching.

Devon

Stupid American Pig · Post by **Stupid American Pig** » Fri Aug 20, 2004 3:38 pm

Well I have a USB2.0 audio interface (edirol UA-1000) and the performance is great, latency can run as low as 3 ms on most projects @24/96 or 16/44.1. The bandwidth is there for USB2 and I have no complaints about it. However, I have read that USB in general is less suited for streaming than Firewire. Further, Firewire is nice and mature, so it should be reliable.

so I guess my point is, get whatever is easiest for your setup. If you already have USB2, get that, if you dont have either, firewire may be the better choice. However I doubt that there would be anymore than 5% difference between the 2 in practice.

rockstar_not · Post by **rockstar_not** » Fri Aug 20, 2004 3:48 pm

Monsterbeetle,

Please post back here on your success/failure and which enclosure you ended up using.

I'm about to buy a HDD and firewire enclosure to replace my 'music' hard drive on my PC, since it's so honking loud.

I want to remotely mount this drive and keep it quiet, since I track and mix in the same room where the PC is.

-Scott

DevonB · Post by **DevonB** » Fri Aug 20, 2004 4:29 pm

double...

DevonB · Post by **DevonB** » Fri Aug 20, 2004 4:30 pm

I found one USB2 enclosure that was doing 19Mb/sec. Not incredible, but a starting number.

Devon

jdg · Post by **jdg** » Fri Aug 20, 2004 4:39 pm

my firewire benchmarked at 26MB/s

interesting.

what drive was in there?

i had the 7200.7 seagate thingy with the 8mb cache

jdg · Post by **jdg** » Fri Aug 20, 2004 4:40 pm

also how did u benchmark?

i used sandra

DevonB · Post by **DevonB** » Fri Aug 20, 2004 4:51 pm

Looks like this was Sandra too.

http://www.short-media.com/review.php?r=250&p=4

Devon

monsterbeetle · Post by **monsterbeetle** » Fri Aug 20, 2004 9:44 pm

Happy to see some feeback.

the 19MB/s is not an unusual figure, but you'll find out that most often thos cheapo USB2 enclosures can't get past 15MB/s.

The theoretical 60Meg/s see far out from reach.

I found a pseudo benchmark for a globalwin USB 2.0 enclosure that claimed a 32Megs per sec. sustained transfer rate on a 1Gig File. I'm really doubtfull.

The consensus is on the Icy Box enclosure, with a blistering 25 Megs per sec on firewire, and a lesser 17 megs per sec on USB 2.0.

I'll report to you guys as soon as I get the damn box! I think I'll just go for a higher quality USB/FW combo, you never now...

Crackbaby · Post by **Crackbaby** » Fri Aug 20, 2004 9:54 pm

I dont know if this would be helpfull.

I have an external 20Gb USB2.0 harddrive. It is not using an enclosure, its a *pure* external.

If i use loops from a samplecd, will that do for streamingtest? I dont know if cubase will load those to memory since the loops are short .. is there anyway i can test trackcount with loops here?

Perret · Post by **Perret** » Sat Aug 21, 2004 8:27 am

Well, 25 mono tracks of 48kHz/24bit audio consume 25*48000*24 = 28.8 megabits per second of bandwidth. This is equal to 28,8/8 = 3.6 megabytes per second (1 byte = 8 bits). The USB2.0 specification is 480 megabits (=60 megabytes) / second. So from a bandwidth point of view there is no problem. However, my understanding is that USB devices consume more CPU power.

From a purely bandwidth point of view you should be able to run both the external harddrive and the soundcard through Firewire without any problems. I don't know whether there are any specific reasons not do to this though. Both the USB2.0 and the Firewire controller end up on the PCI bus anyway, and this is probably the major source of latency issues. PCI sucks

raw track count : USB 2.0 vs FW external drive