View Full Version : I need help!

12-23-2001, 02:31 AM
1. My RAID array is this - 4 18 gig Seagate Cheetahs, Adaptec 2940U2W. Completely LVD all drives are external. So how come i get only 63MbPS?

P.S i did not build this RAID but ribbon cables connecting drives are pretty cheesey, look like plain old IDE.

2. Are U160 cables and terminators compatible with Ultra2 drives

3. I REALLY want to switch all my cables and terminators to MacGuru. Dumb question - do Mac Guru cables and stuff work on Windows systems?

Sorry for the long post but i need to get these drives up to at least 80 MbPS.

Thank You,

12-23-2001, 09:26 AM
First thing I would do is move off the UW card to something newer, and cables are cables are cables, yes.

U2 is limited to 80MB/s. Even a single X15 Cheetah can deliver 52MB/s sw speeds. Your cables may look like the problem but I'd start with controller, then terminator, and the drives themselves.


12-23-2001, 09:58 AM
What is the model # of your drives?

yes the Granite cables that the Gurus sell will work just fine with windows

Yes U160 are compatible with U2W

You should take Gregory's advice and start at the controller though...

12-23-2001, 02:11 PM
O.K, i will start with controller (u160). I plan on re-building complete array, from the case to cables and keep the same drives.

2 drives are ST318404LW (which i believe are U160) and 2 are ST118202LW (U2w).

So, can these drives maintain 80 MbPS - with new controller and cables?

Thanks for the info,

12-23-2001, 08:21 PM
With an U160 controller my somewhat educated guess is that the 2 ST318404LW's in a raid would maintain 80MB or greater they should do that fairly easily.

However your U2W drives MAX rated speed (In theory on paper) is 80MB a sec each expect a single drive in the real world to deliver 40MB a sec My guess in this case is that on a U160 card you would approach 80MB in a raid but I would not count on maintaining that speed in a sustained read/write

A great idea would be to get the new card and then do some bench testing to see what you get in your setup before you get in a situation where you are depending on something that may not be there. Also around here somewhere in the MacGurus site are archives of past benchmarks an various setups so you can get an idea of what to expect (I have forgotten where those are at though somebody help me out with the address of those benchmarks)