EXS 24 Logic Sampler Users Group

>> From: "Jeff Fisher" jefisher@...
>>>
>>
>>> thinking of moving from a Powerbook G4 1.67 up to a Macintel Laptop
>>> to run a huge live kit in logic. The new books still have a
>>> 2Gig Ram limit...my present live template exceeds that and memory
>>> paging begins. On the G4 this means audio glitching as OSX
>>> moves data to and from the system disk. I was wondering if the Intel
>>> boxes with their much faster buses can thus run memory-hogging
>>> setups without interrupting the flow of audio (a dual G5 with only
>>> 512 Megs of RAM was able to do this)...Not looking for  simultaneous
>>> playback of many tracks, just the ability to load way way beyond the
>>> RAM ceiling with VSL and plugs in a live situation..with no audio
>>> stuttering
>>> anybody care to test this out
>>> THX Jeff

I wrote:

>> Remember, hard disk access isn't any faster than it's been for the
>> past few years.


From: "Jeff Fisher" jefisher@...

> Hmm, don't the new Powerbooks all uses SATA drives (although methinks
> 5400RPM)? perhaps if I boot off an external drive...
> I guess I'll have to go to the store to run some tests...
> thanx   Jeff

SATA is a faster *bus* than PATA, so it can handle more data. But you  
were never saturating the bus with PATA; the important issue for  
streaming samples is how quickly the drive itself can deliver the  
data. The best hard drives are WD Raptors, which are 10K RPM drives  
with a seek time 50-60% of a regular 7200 RPM ATA or SATA drive's  
spec. They do deliver a few more voices.

However, you're asking whether a hard drive is a substitute for RAM  
access, and it clearly isn't. If EXS forces OS X to start pretending  
the hard drive is a RAM buffer for loading sample starts, you're  
going to get crashes while the machine swaps that data into RAM.

Memory is thousands of times faster than any hard disk, and the only  
way to pay samples is from RAM. Streaming samplers store the bulk of  
the samples on the disk, but they still read from the RAM buffer.

I've avoided using the term "virtual memory," because EXS uses  
(misuses?) it to mean sample-streaming. People aren't usually talking  
about EXS when the general term - they're talking about the OS  
running out of RAM and using a temporary hard disk buffer that it  
swaps out.

Nick Batzdorf, editor/publisher
Virtual Instruments Magazine - the world of softsynths and samplers
www.Virtualinstrumentsmag.com
1-877 VImagzn (846-2496)
818/905-9101, cell 590-9101




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