Scratch Disk on External USB 2.0 Drive?

From: "Robert E. Williams"

Can I put Scratch Disk space for PS 7.0 on a dedicated, 20 GB external USB 2.0 H.D.?

Yes, I did this for a while, trying two different externals, one a 160 GB Firewire drive and later a 120 GB USB 2 drive.

However, I found that having the scratch disk on my C drive was actually faster than using an external.

FWIW I ran a couple of tests, comparing various scratch disk options.

With a lengthy action that did some common tasks on a 555 MB drum scan here’s what I got using CS, with RAM allocation set to 50% on a 1.5 GB RAM system …

2nd hard drive as scratch — 321 secs
C drive as scratch — 411 sec or 1.28x longer
1394 external 7200 rpm — 522 sec or 1.63x longer
USB 2 external 5400 rpm — 745 sec or 2.32x longer

So you’re better off with a 2nd internal drive or just using C, if you have the free space on C. Now I just use the externals for backup storage.

I also ran the same action on two test cases with the RAM set to 86% or 1205 MB (my normal allocation)…

2nd HD as scratch — 205 sec
C drive as scratch — 303 sec or 1.48x longer

So increasing the memory allocation speeded it up quite a bit more than anything else one might do with the disks, given the same CPU etc.

Thanks for any input.

Hope this helps. You can pick up 180 GB Hitachi HD’s for around $80 after rebate at your local Frys (or at least around here) and it just takes a few minutes to add one, plus formatting time.

Bill

Bill Hilton wrote:

From: "Robert E. Williams"

Can I put Scratch Disk space for PS 7.0 on a dedicated, 20 GB external USB 2.0 H.D.?

Yes, I did this for a while, trying two different externals, one a 160 GB Firewire drive and later a 120 GB USB 2 drive.

However, I found that having the scratch disk on my C drive was actually faster than using an external.

FWIW I ran a couple of tests, comparing various scratch disk options.
With a lengthy action that did some common tasks on a 555 MB drum scan here’s what I got using CS, with RAM allocation set to 50% on a 1.5 GB RAM system …
2nd hard drive as scratch — 321 secs
C drive as scratch — 411 sec or 1.28x longer

How much space did you allow on the C drive for scratch? Was the scratch on a separate partition of the C drive or was it in the same Partition as Windows?

1394 external 7200 rpm — 522 sec or 1.63x longer

USB 2 external 5400 rpm — 745 sec or 2.32x longer

Interesting Result…. Looks like most of the improvement came from the 7200 RPM Disk speed rather than from the Firewire interface itself. IF improvement in speed is linear with disk speed, Firewire with a 5400 RPM drive would give 696 seconds instead of the actual USB 2 speed of 745. Not a whole lot of difference due to the interface (as expected).

So you’re better off with a 2nd internal drive or just using C, if you have the free space on C. Now I just use the externals for backup storage.
I also ran the same action on two test cases with the RAM set to 86% or 1205 MB (my normal allocation)…

2nd HD as scratch — 205 sec
C drive as scratch — 303 sec or 1.48x longer

So increasing the memory allocation speeded it up quite a bit more than anything else one might do with the disks, given the same CPU etc.

Thanks for any input.

Hope this helps. You can pick up 180 GB Hitachi HD’s for around $80 after rebate at your local Frys (or at least around here) and it just takes a few minutes to add one, plus formatting time.

Isn’t that incredible? Less than 50¢ per GB, WOW!!!

How do you format a new USB 2 drive.
Do you have to hook it up as an IDE drive to format it?
Do you use the Fdisk and Format utilities or a special Floppy or CD provided by the manufacturer of the drive?

Bill

Thanks for that valuable and interesting input.
Maybe I’ll just add another 512 MB of RAM to my existing 512MB. I dont have an open bay for a second drive and I don’t deal with files nearly as large as yours, so maybe 1 GB of RAM and a separate 5 GB partition on my main drive will do well for me.
Bob Williams

Using USB for data transfer is not a good idea when the data is in constant use (like a scratch disk) USB 2.0 and Firewire are a little better than straight USB 1 but not by enough.

An EIDE mode 4 drive can transfer data aproximately twice as fast as USB 2.0 can. If you have a physical limitation on how many drives you can use in your PC, install an after market SATA, PCI card and use a Serial ATA drive. Daisy chain them too! You’ll get the speed then and PS won’t crash from lack of data feed.
The Yowie
——————–
"Robert E. Williams" wrote in message

Can I put Scratch Disk space for PS 7.0 on a dedicated, 20 GB external USB 2.0 H.D.?
With Win Xp (Home Ed.), can (should) I leave the entire drive a single partition and assign the entire 20 GB to that partition? Or should I create a bunch of partitions on the drive and divvy up the 20 GB space between the various partitions?
Is there some maximum number of GBs that I can I assign to any given Partition?
Thanks for any input.
Bob Williams

Bill Hilton wrote:

With a lengthy action that did some common tasks on a 555 MB drum scan here’s what I got using CS, with RAM allocation set to 50% on a
1.5 GB RAM system …

2nd hard drive as scratch — 321 secs
C drive as scratch — 411 sec or 1.28x longer

From: "Robert E. Williams"

How much space did you allow on the C drive for scratch?

I let it default to whatever Photoshop needed (I know, I’m lazy). My C drive is 200 GB so I didn’t worry about limiting the scratch size.

Was the scratch on a separate partition of the C drive or was it in the same Partition as Windows?

Same partition. In theory if you create a partition and it’s physically distant from your data such that the heads have to move far every time it switches from program to scratch it might actually slow you down. You could try this both ways (separate partition vs no partition) and time it and report back, it would be interesting to know if this theory is valid or not.

1394 external 7200 rpm — 522 sec or 1.63x longer

USB 2 external 5400 rpm — 745 sec or 2.32x longer

Interesting Result…. Looks like most of the improvement came from the 7200 RPM Disk speed rather than from the Firewire interface itself.

I don’t think so … the 7200 rpm drive has both USB and 1394 ports and I’ve run tests moving big blocks of data (25 GB) from the HD to each of the externals using USB2 and there was little difference between the 7200 vs 5400 rpm USB drives. Also, I mentioned the USB2 5400 drive took 745 sec to run this action … I ran the same action with the 7200 rpm drive connected to USB2 instead of 1394 and it actually took a few seconds longer (773 sec). This is counter-intuitive and I was going to re-run those tests to double check it eventually, but since I have to drag one of the drives from another machine I haven’t bothered (as I said, I’m lazy). All I can surmise is there’s a bit more logic in front of the transfer with the dual interface drive, which slows the transfer rate a bit.

Anyway, nothing I saw would support saying the 7200 drive is a lot faster than the 5400 rpm drive with the same port type for these transfer rates (for other types of data, perhaps it’s different), but 1394 was clearly faster than USB2 regardless of the rpms of the USB2 drive.

IF improvement in speed is linear with disk speed, Firewire with a 5400 RPM drive would give 696 seconds instead of the actual USB 2 speed of 745.

But it’s not linear with disk speed, so toss that theory. In theory USB 2 has a faster transfer rate than 1394 (480 Mb/s vs 400 Mb/s) but in practice the overhead and protocols mean 1394 is somewhat faster.

How do you format a new USB 2 drive.
Do you have to hook it up as an IDE drive to format it?

I bought Maxtors and there was an option to format NFS or FAT32 with the supplied software, you don’t have to hook up an IDE port to format it. Very easy to do. You can find these on sale at Frys occasionally for about $1 per GB after rebate.

Do you use the Fdisk and Format utilities or a special Floppy or CD provided by the manufacturer of the drive?

Supplied by Maxtor … no problems.

Thanks for that valuable and interesting input.
Maybe I’ll just add another 512 MB of RAM to my existing 512MB.

The longer you can stay in RAM and avoid the scratch disk the faster it runs, regardless of how you set up your scratch drive … I’d definitely bump up my RAM first.

Bill

The Serial ATA drive is another pretty good idea. I had completely forgot about that option.
I’ll investigate.
Bob Williams

The Yowie wrote:

Using USB for data transfer is not a good idea when the data is in constant use (like a scratch disk) USB 2.0 and Firewire are a little better than straight USB 1 but not by enough.

An EIDE mode 4 drive can transfer data aproximately twice as fast as USB 2.0 can. If you have a physical limitation on how many drives you can use in your PC, install an after market SATA, PCI card and use a Serial ATA drive. Daisy chain them too! You’ll get the speed then and PS won’t crash from lack of data feed.
The Yowie
——————–
"Robert E. Williams" wrote in message

Can I put Scratch Disk space for PS 7.0 on a dedicated, 20 GB external USB 2.0 H.D.?
With Win Xp (Home Ed.), can (should) I leave the entire drive a single partition and assign the entire 20 GB to that partition? Or should I create a bunch of partitions on the drive and divvy up the 20 GB space between the various partitions?
Is there some maximum number of GBs that I can I assign to any given Partition?
Thanks for any input.
Bob Williams

Not if the OS marks it as a removable drive (which it should). And that is going to be MUCH slower than using an internal drive (or even an ATA or SCSI attached external drive).

20GB is tiny – leave it as one partition.

Chris

In article , Robert E. Williams
wrote:

Can I put Scratch Disk space for PS 7.0 on a dedicated, 20 GB external USB 2.0 H.D.?
With Win Xp (Home Ed.), can (should) I leave the entire drive a single partition and assign the entire 20 GB to that partition? Or should I create a bunch of partitions on the drive and divvy up the 20 GB space between the various partitions?
Is there some maximum number of GBs that I can I assign to any given Partition?
Thanks for any input.
Bob Williams

Thanks for that info.
Bob

Chris Cox wrote:

Not if the OS marks it as a removable drive (which it should). And that is going to be MUCH slower than using an internal drive (or even an ATA or SCSI attached external drive).

20GB is tiny – leave it as one partition.

Chris

In article , Robert E. Williams
wrote:

Can I put Scratch Disk space for PS 7.0 on a dedicated, 20 GB external USB 2.0 H.D.?
With Win Xp (Home Ed.), can (should) I leave the entire drive a single partition and assign the entire 20 GB to that partition? Or should I create a bunch of partitions on the drive and divvy up the 20 GB space between the various partitions?
Is there some maximum number of GBs that I can I assign to any given Partition?
Thanks for any input.
Bob Williams