SCSI CF slower than IDE CF...Why?

[Sandman]

I have a CF that I can connect to my A4000 thru:

1. CF->IDE adaptor to A4000 IDE

2. CF->IDE adaptor to IDE->SCSI adaptor to WarpEngine SCSI

3. CF->IDE adaptor to IDE->SCSI adaptor to WarpEngine SCSI w/ SCSI HD on chain also.

Sysinfo reports speed of the CF fastest on #1, next #2 and slowest #3(the actual way that I want to set it up).

This seems odd.... Why does the CF on SCSI slow down the most with a real HD also attached?

Any of you experts got any ideas?

Thanks,
Tim

[Sandman]

The rating sysinfo gives for the CF card is 3.5m/sec and 8m/sec for the 10K Quantum SCSI HD even at the best setting...... I guess I was hoping for a little more.

Maybe I would just be better off hooking the CF->IDE to the motherboard IDE and putting the Quantum SCSI HD and IDE CDRW(with the IDE->SCSI adapter) to the WarpEngine.

Just going to be using the CF to transfer files to the HD anyways.

Also, Why would adding anything to the SCSI chain slow the HD down?  I am still green to SCSI in generally.

Thanks again,
Tim

[Sandman]

Ok, here is what I got.

WarpEngine set to no delay, no LUN scan, 100ns sychronous


Case#1:
Quantum 10K SCSI HD (18gb) alone on WarpEngine.....Sysinfo says 8,738,133/sec
CF Card->CF/IDE adaptor->A4000 IDE.....Sysinfo says 2,184,533/sec


Case#2:
Quantum 10K SCSI HD (18gb) on WarpEngine SCSI.....Sysinfo says 8,738,133/sec
CF Card->CF/IDE adaptor->IDE/SCSI adaptor on WarpEngine SCSI.....Sysinfo says 1,8xx,xxx/sec


Case#3:
CF Card->CF/IDE adaptor->IDE/SCSI adaptor->alone on WarpEngine.....Sysinfo says 3,276,800/sec


And I haven't thrown my CDRW into the mix yet.....

Something seems real slow here.....Arrggh! I don't which is the best way to set this all up!:madashell:

Thanks,
Tim

[Sandman]

Thanks for all of the replies...

I know that block size for the CF is 512 and HD is 1024 thru HD toolbox.

I haven't tried switching LUN Scan from off to on... not really even sure what this is for.

I'll probably only be using the CF card for transfering files to and from the HD so maybe I should put in on the A4000 IDE anyways.  That would eliminate the A4000's boot delay also wouldn't it?

[Sandman]

The CF card that I am using is the A-Data Speedy 8GB (http://www.adata-group.com/EN/product_show.php?ProductNo=ACFCZZZBK)

It seems weird that I get the best performance with it alone on the WE SCSI first, then next alone on the A4000 IDE and worst performance on the WE SCSI along with the HD...... must be the IDE->SCSI adapter but that is rated @ 20mb/sec so I am at a loss.....
 :crazy:

Thanks for all of the replies......

[Sandman]

I am starting to think that the majority of the problem is with the CF->IDE adapter as it was a inexpensive one and I know that it doesn't do DMA.

I am thinking now that it might be best to put the CF on the A4000 ide (to get rid of boot delay) and live with a slower transfer speed since I will just use it to transfer files.  Then I could put my CDRW on the SCSI->IDE adapter hooked to the WarpEngine and then have a nice, fast burner.

Sound about right?  Any other ideas appreciated....

Thanks