Why is Backup to External Hard Drive so Slow?

dan239 · 15th January 2005

I recently installed an external hard drive that is USB 2.0. When I try to backup my system using Ghost and put it on this drive it will take 45 minutes or more.

I can do a system backup using Ghost and put it on my second internal hard drive and it will take about 6 minutes. I can then copy or move this backup folder to my external hard drive in less than 5 minutes.

This is not a major problem, but I would like to know why the difference in the backup time between the two drives.

Thanks

Daniel

surferdude2 · 15th January 2005

The USB port just won't transfer data as fast as a hard drive. Without getting deeply into why and revealing that I don't really understand all that, let's just say a 40 wire cable has more possibilities than a 6 wire cable. Who knows, maybe 6 2/3 times the possibilities.

Nah, too simple.

Let's see now...45 minutes divided by 6 minutes equals a ratio of 7 1/2 : 1

Close enough!

**charlesvar** · 15th January 2005

Hello dan,

See what the policy setting for your USB drive is.

Bring up the drive > right click > properties > hardware tab > hightlight the drive > properties button next to Troubleshoot > Policies tab > tick "optimize for performance.

This should not be done IMO if this drive is constantly uplugged/plugged back in. If it is and is being used that way, uninstall/re-install procedure has to be followed each time. For reference USB Connection Interrupted and lost

Regards - Charles

dan239 · 15th January 2005

Surferdude2;
I may not have made myself clear that the external drive appears to transfer data as fast as the internal drive. It is just much slower than the internal when doing a backup using Ghost.

Charles;
I looked at what you suggested under Policies and "Enable write caching on disk" is checked. The "Optimize for performance" is ticked and grayed out. The " Optimize for quick removal" is not ticked and grayed out.

I should point out that I turn this drive off when not in use and and it has not caused a problem.

Thanks

Daniel

surferdude2 · 16th January 2005

The actual across the board comparison of the ratio between the speed of a Eide HD drive using DMA and a USB drive is approximately 8:5. That doesn't totally explain your greater ratio but there may be other factors at work also.

I would suggest checking with Symantec for any new drivers that might be helpful.

Have you tried running the Ghost program from different source media? From within Windows (causes reboot to command mode) - from a boot floppy - from a boot CD. Your results may vary. If not, then all modes are using the same driver and that's where Symantec comes in again.

dan239 · 17th January 2005

After doing some reading on the Symantec site, it appears that the way Ghost is functioning in my machine is normal. They are a little vague about my particular situation, but I did conclude that Ghost will work with some external devices through USB only at USB1.1 speed. I think this answers my question.

Thanks Surferdude2 for suggesting that I check with Symantec.

Daniel

**Zander** · 17th January 2005

If Ghost runs in DOS I would guess it has something to do with memory management. Windows does a lot better job of it than DOS and can do things much faster than DOS. An example: In Win9X I used to boot to Dos to delete the temporary internet files so as to also do away with the index.dat. If there was a large amount of files to delete you could delete them in Windows and it would take a matter of a few seconds. Doing the same amount in Dos without smartdrv loaded could take minutes (sometimes 10-15 depending on the size of the folder). Loading smartdrv helped but it still didn't do the job near as fast as it would in Windows. I would guess that what you're seeing is as they say, perfectly normal. Job for job you just aren't going to get it done as fast in DOS as you will in Windows.

Also, the way your hardware performs in the two different operating systems may be a factor in DOS vs Windows.

dan239 · 17th January 2005

Zander;
Ghost does run in DOS no matter which drive I am storing it to. As far as I know, Ghost cannot be run in Windows because it is doing a complete image of that drive.

Daniel