Scratch Disk Set Up

[felix5616]

Can anyone tell me how to set up(including parts/components) an external scratch disc for my powermac dual 2.5 G5 computer > i am running large files on photoshop CS3

[Marko]

You can connect an external drive through either Firewire or USB, but you would be much better off adding an internal SATA (or SCSI if you have the controller built in) drive.

Either way, once you connect the physical drive, open Photoshop preferences and under Performance section select your new drive as the only scratch disk (your main disk will mostly likely be checked by default - uncheck it).

Also, make sure that your new scratch disk is dedicated - don't use it for anything else.

Hope this helps.

Marko

[Don Hutton]

You really want a high speed internal SCSI drive. If you're messing with big scans, it is the only way to go. I have a small (34 Gig) 15000 RPM SCSI drive as my scratch disk and it works a treat. As Marko pointed out, it needs to be dedicated.

[felix5616]

an i put a scsi drive in a Mac G5?
how about a 10,000RPM SATA drive?

[Don Hutton]

You'll need a SCSI controller, but sure, it can be done.

Try your SATA drive first - make sure it's dedicated - if you still need more speed, you could throw money at something else...

[Marko]

I wouldn't be spending too much money on improving a G5. There is a point of diminishing returns compared to the performance of new IntelMacs - even a new iMac which has pretty limited expansion abilities will run circles around it.

As Don says, try adding another internal SATA drive and perhaps even some RAM, they're both cheap these days. But if that's not enough, you might, IMO of course, be better off considering a new Mac.

[Sevo]

You really want a high speed internal SCSI drive.

These days, a fast SATA drive is more advisable - good SATA drives are about a magnitude cheaper, and they can do native command queueing, which used to be the last reason to get SCSI for workstation type computers.

Besides, hooking up SCSI is not easy any more, as computers have made the step to PCI-E, where only server grade SCSI cards followed, at a price - a contemporary SCSI card can cost more than as a good laptop, while cheap old cards off ebay are bus-bound and would be outperformed by any cheap SATA drive.

Sevo

[Athiril]

I have a pair of WD 640GB's in SATAII running in RAID0 for a dedicated scratch/page file.

Runs a treat with the Quad Core, and GTX260, 4GB ram :) built the whole thing last year for $800 AUD, CS4 runs wonderfully with huge images :)

[bernal]

I don't think is practical to add a SCSI drive to a G5. But I'd go with the advice to add as much RAM as you can afford in addition to installing a second small internal SATA drive to be used as a dedicated scratch disk.

I don't know how much memory you can install on your Mac, but I have 8GB on my G5 (the maximum it takes), which is plenty for my large files. Because I don't use all the memory, even when working with the largest of files, I installed a 500GB internal drive with a 50GB first partition for use as a scratch disk, just in case, and the second partition for backup, a $60.00 set up.

[oris642]

Best guide to computers (Macs) and Photoshop that I have come across:

http://macperformanceguide.com/

[Peter von Gaza]

Go 64-bit Photoshop and buy lots of RAM. I'm running an overclocked quadcore intel core i7 120 at 4 GHZ and have 12 GB of ram (6 slots). I'm just waiting for cheap 4GB sticks then I can have 24 GB of ram. So why bother with scratch disks???? I work with satellite imagery and have loaded 10GB images into memory. I suppose if your in the Mac world this might not be possible :confused:

Peter

[Marko]

Go 64-bit Photoshop and buy lots of RAM. I'm running an overclocked quadcore intel core i7 120 at 4 GHZ and have 12 GB of ram (6 slots). I'm just waiting for cheap 4GB sticks then I can have 24 GB of ram. So why bother with scratch disks???? I work with satellite imagery and have loaded 10GB images into memory. I suppose if your in the Mac world this might not be possible :confused:

Peter

Not really, but neither are the blue screens... ;)

The reason why NOT to set up scratch disks in RAM is that that can actually make everything slower. 64-bit OS requires more RAM than 32-bit one to begin with. And even 24GB can easily get filled up as scratch.

When that happens, RAM starts getting paged to the HD and RAM disks are the first to go, so it's double-trouble.

[Athiril]

A 64-bit OS doesnt actually require more ram than a 32-bit OS.

[Marko]

All the instructions are double the size, qwords instead of dwords, etc. System overhead oughta reflect this in some way. I'm not saying that the increase is double, but it should still be there.

This, however, was just a side quip. The real point was to NOT use RAM disk as scratch disk regardless of OS. The reason behind this is that even the biggest RAM disk runs a good chance of overflowing and causing the memory to start paging to the physical HD. When that happens, RAM disk is the first to go because it is already data that is not immediately needed.

The net effect is slower performance because the scratch data (photoshop) gets swapped twice in and twice out.

Better performance gain could be realized by using a dedicated SATAII RAID 0 pair (as you are doing) and leaving available as much memory to Photoshop as it can use.

[Athiril]

They could use one of those internal (or two in RAID0) controllers that you put memory in that acts as a HD, thus its outside of ram. :)

[Brian Ellis]

I'm no expert but based on my experience I'd strongly suggest an internal drive rather than an external. When I set up an external drive as a scratch disc it slowed everything way down so I quit using it. Now I have an 8 gig PC with Vista and it flat out flies so I don't worry about a scratch disc any more.

[Marko]

They could use one of those internal (or two in RAID0) controllers that you put memory in that acts as a HD, thus its outside of ram. :)

RAIDed solid-state RAM disks? Yeah, that does sound interesting. :cool:

I'm just not sure if it can (yet) be cost-effective enough.

[Athiril]

It is as much as the memory is.

Think it's the iRAM or something, us PC users have had it for a long time :)

Here it is:
http://en.wikipedia.org/wiki/I-RAM

[Doug Dolde]

I have three WD 1TB RE3 drives in raid 0, with the outer partition setup for scratch, remainder for data. 64 GB per drive, way more than enough. My OS X drive is an 128 GB Intel X-25M solid state drive. Needless to say my Mac Pro flies and reads/saves files extremely fast.

The only thing that slows me down if I haven't used the data drive in a while and it's in energy saving sleep mode. I'm careful to back it up to an external drive at least once a week. (I just use SuperDuper to back it up).

[jim kitchen]

There are some interesting articles here, that I referenced in the past:

http://www.macgurus.com/guides/storageaccelguide.php

and here, along the bottom left side for "Photoshop Acceleration:"

http://www.macgurus.com/index.php

jim k