WTB: SCSI Controller and Cables

[DarkStar02]

SCSI Ultra320 80pin

I know absolutely nothing about SCSI but I am going to be buying two 10k rpm SCSI drives and they use what is shown above. I need a controller card cable of raid and 2 cables.

[zepper]

I have a couple of cards and cables here but need more info before I'd offer them. SCSI requires more brain sweat than ATA, so are you sure you're up for it. Lack of prep before hitting the market reveals much...

1- Which drives (make, model no. and size) are you buying and why are you considering RAID?

2- What RAID level? (0, 1, 0+1, etc.)

3- Two drives on SCSI don't require two cables even for most RAID levels or JBOD.

4- Cards with 80-pin connectors are rare - 80-wire cables even more so. Better to get a couple of 80-to-68pin adapters on eBay - about $5. each - and use a standard 68-pin card and cable.

5- What types of card slots does your mobo have?

Lots of good SCSI info - http://www.scsifaq.org

.bh.

[Xaotic]

Lets hit the basics:

The 80 pin or SCA connector is primarily intended for use in hot swap enclosures. They can be run using adapters, prices range from 10.00-40.00 plus shipping. I've generally had good luck with Manhattan's 10467-320. The adapters can be dodgy and cause signal problems, it's a crapshoot. Cables are required along with active terminators. Twisted pair is best. I try to avoid rounded cables.

RAID is an expensive proposition on SCSI. The initial problem is conventional PCI architecture. The PCI 2.0 bus saturates at 133MB/s theoretical(100-115MB/s actual). This means that unless you have a PCI-X or PCI-E slot and controller, onboard SATA or PATA RAID-0 may be faster. Generally, on a standard PCI bus, there's no reason to hang a controller faster than U160.

Controllers themselves are another potential drawback and bottleneck. Faster controllers get expensive. Since you're likely to want RAID-0 or RAID-1, cheaper processors are possible. For this purpose, the LSI 21320-R is one of the better controllers(most of the U160 controllers with RAID use on controller processors and will give very disappointing performance). Prices tend to be prohibitive, they were 130.00 when they came out, but run 250.00 now.

The bottom line is research carefully before you buy. I am a SCSI fanatic, but it's more for data integrity than speed. One other thing, look at the comparative performance on storagereview.com before buying. Sometimes faster is less expensive.

[DarkStar02]

I have a couple of cards and cables here but need more info before I'd offer them. SCSI requires more brain sweat than ATA, so are you sure you're up for it. Lack of prep before hitting the market reveals much...

More brain sweat? What do you mean?

1- Which drives (make, model no. and size) are you buying and why are you considering RAID?

I can get two Fujitsu MAP3367NC's for $90.00 and I want to put them in a RAID-0 array.

2- What RAID level? (0, 1, 0+1, etc.)

Raid-0 for speed.

3- Two drives on SCSI don't require two cables even for most RAID levels or JBOD.

I'm not sure what JBOD is, but you're saying I can hook up two drives with one cable and one card?

4- Cards with 80-pin connectors are rare - 80-wire cables even more so. Better to get a couple of 80-to-68pin adapters on eBay - about $5. each - and use a standard 68-pin card and cable.

Will do.

5- What types of card slots does your mobo have?

2 PCI Express x16 slots
1 PCI Express x1 slot
1 PCI Express x4 slot
2 PCI

[zepper]

I just did some research and found that the latest rev of the Raptor will beat the Fujitsu MAT (latest) series of 10k drives on anything but the server application tests. So I'm thinking it would be less hassle and perhaps cheaper for you to get one 74meg Raptor. As to get the most out of your two SCSI drives, you'll need a PCI Express SCSI adapter card and those aren't cheap!

Now if you had a server mobo with a 64-bit/66MHz PCI slot, you could get a reasonably priced 64-bit U160 card from LSI that would do the trick (as the two MAP drives can do a bit over 70MB/sec each). It'll be a while before PCI express cards become reasonably priced.

,bh,

[DarkStar02]

Originally Posted by zepper

I just did some research and found that the latest rev of the Raptor will beat the Fujitsu MAT (latest) series of 10k drives on anything but the server application tests. So I'm thinking it would be less hassle and perhaps cheaper for you to get one 74meg Raptor. As to get the most out of your two SCSI drives, you'll need a PCI Express SCSI adapter card and those aren't cheap!

Now if you had a server mobo with a 64-bit/66MHz PCI slot, you could get a reasonably priced 64-bit U160 card from LSI that would do the trick (as the two MAP drives can do a bit over 70MB/sec each). It'll be a while before PCI express cards become reasonably priced.

,bh,

Thanks.

[zepper]

I got to thinking that if your mobo has SATA II, you could get a pair of Hitachi 7K80 drives (80 GB sata II) and have a very hot RAID 0 setup. I'm running just one 7K80 in my machine (on a SATA I controller) and it easily beats the older generation 10k U160 drives I have in here too.

.bh.

PS: I did some more thinking and wanted to remind you that if you do a RAID-0 with those two drives, be sure to keep a good verified backup (disk images are NOT reliable backups) as the odds of failure are somewhat increased in RAID-0 than over a single drive. You may also want to look at the FAQ on RAID over at storage review. Both SR and Anandtech have done articles comparing RAID-0 and single drive performance and have concluded that you only get significant performance increase with long reads/writes like happens when booting up or loading large files for video editing. The performance increase in normal applications is in the 10% area. So weigh the benefits/risks.bh.

[DarkStar02]

What makes those drives so fast? They are only 7200RPM.. ?

[zepper]

I guess the higher density platters and the large cache on the drive - perhaps they came up with a more effective caching algorithm too. Nothing much else would account for it. Perhaps they really aren't as fast as they seem - just the contrast, ya know...

You might want to check out this thread: http://www.i4memory.com/showthread.php?p=21300 - scroll down to the HD Tach graphs on the 2x raid 0 and 4x raid 0 using the 7K80s. Schweet!

.bh.

[DarkStar02]

Originally Posted by zepper

I guess the higher density platters and the large cache on the drive - perhaps they came up with a more effective caching algorithm too. Nothing much else would account for it. Perhaps they really aren't as fast as they seem - just the contrast, ya know...

You might want to check out this thread: http://www.i4memory.com/showthread.php?p=21300 - scroll down to the HD Tach graphs on the 2x raid 0 and 4x raid 0 using the 7K80s. Schweet!

.bh.

I'm not sure what that means but I think I'll buy some just because they are so cheap.