• We’re currently investigating an issue related to the forum theme and styling that is impacting page layout and visual formatting. The problem has been identified, and we are actively working on a resolution. There is no impact to user data or functionality, this is strictly a front-end display issue. We’ll post an update once the fix has been deployed. Thanks for your patience while we get this sorted.

Some dumb SCSI questions :D

XMan

XMan

Lifer
I got a great deal on some 36GB Atlas 10K IV's, so I thought, what the hey, I'll buy a controller card and have a RAID 0 array for my OS.

This card seems as though it will fill my needs nicely:

http://www.newegg.com/app/ViewProductDesc.asp?description=16-118-018&depa=0

I don't have PCI-X slots, but if I understand correctly I can put it in a standard slot at the expense of speed. Or is this a bad idea? If so, does anyone know of a SCSI RAID controller in a standard PCI form factor? It doesn't necessarily have to be U320, U160 will be fine, I don't think two drives in RAID 0 will push 160.

As it's a dual channel controller, can I use two short, single device cables to connect the drives to the controller?

I also have two terminator blocks . . . is it better to use those to terminate the chain, or should I stick to the jumpers on the drives?

Thanks for any input!

EDIT - another question . . .

This card . . .

http://www.newegg.com/app/ViewProductDesc.asp?description=16-118-008&depa=0

Is only single-channel, but I'm not going to break the 15 device limit. I'd have to buy a cable, as well, which would probably eat up the savings from the other card. Any advantages to buying this over the other?
 
Both cards are a solid choice. The prime choice for SCSI on slow PCI busses, the LSI U160, has a very inflated price at Newegg though. I've seen this card go for $59 and less. Try to find a bargain on that one! The most useful cards for desktop/workstation boards are those that have one fast SCSI channel for hard disks and one slow channel for other peripherals. Tekram 390U4W, LSI 21003, Tekram 390U3W. The Tekrams come in retail packs with all the cables, bits and pieces you'll possibly need. Check for those too.

U2W and faster drives do NOT have on-drive termination capability, you MUST have terminator blocks on the cable. Cables also must be twisted-pair "LVD capable".
 
i think thats since the pci bus is limited to 133mb per second and a average hard drive tops at 60 and this is double the speed it would onlt need about 120mb so the pci bus is okay and both choices are good one's
 
Originally posted by: Peter
Both cards are a solid choice. The prime choice for SCSI on slow PCI busses, the LSI U160, has a very inflated price at Newegg though. I've seen this card go for $59 and less. Try to find a bargain on that one! The most useful cards for desktop/workstation boards are those that have one fast SCSI channel for hard disks and one slow channel for other peripherals. Tekram 390U4W, LSI 21003, Tekram 390U3W. The Tekrams come in retail packs with all the cables, bits and pieces you'll possibly need. Check for those too.

U2W and faster drives do NOT have on-drive termination capability, you MUST have terminator blocks on the cable. Cables also must be twisted-pair "LVD capable".
Click to expand...

If I don't use LVD capable cables, it will step the speed down, correct? Where's a good place for SCSI cables, Newegg doesn't seem to have any.
 
You'll risk data corruption with unsuitable cables, although the software will be doing its best running a so called "domain validation" test before going U160.
Buying "retail pack" SCSI cards gives you a basic set of cables and terminators. A good starting point for shopping is www.storagereview.com 's "check storage prices" feature.

http://storagereview.pricegrabber.com/search_getprod.php/masterid=689487 (LSI U160, card only, $50!)
http://storagereview.pricegrabber.com/search_getprod.php/masterid=306756 (Tekram 390U3W dual-channel U160/UW40, retail pack)

Current generation SCSI HDDs reach up to almost 100 MB/s _actual_ throughput, saturating "normal" PCI with just one unit.
 
Adaptec have repeatedly angered me with short-lived card support and more compatibility issues and driver problems than I find funny - something LSI has never ever let me down on. The beauty in the LSI U320 series cards is that they all use the same driver set, RAID or not, and the SCSI chip (which contains a RISC processor and some RAM) does the actual work, even in RAID 0/1.

Your entry point into SCSI RAID 0/1 is the LSI 20320R (single channel); then there's the 21320R (twin SCSI channels for full-blast RAID 1+0 performance); and finally the 22320R that offers both channels on internal AND external connectors. If you feel like spending even more, venture into the "MegaRAID" series host adapters that accompany the SCSI chip with another RISC processor and lots of RAM on the card for RAID5.

Mind that some of the "retail" kits do not include cables.
 
Looks like it's the 20320R, then. The Adaptec doesn't include cables, either, and it's more expensive. Plus I can get the LSI from the 'egg . . . I get phobias when I buy from anywhere other than them. 😀

Thanks for all the input, Peter.
 
If buying from newegg, I recommend you get the 21320R, it's only $22 more, offers twice the horsepower, and can do RAID 0+1. The 20320R can only do either 0 or 1. (RAIDing four drives on a single SCSI channel wouldn't make much sense anyway.) The only drawback of the 21320R is it's a full-height card, thus doesn't fit low-profile blade servers or somesuch. Not relevant for normal PC use.

http://www.newegg.com/app/ViewProductDesc.asp?description=16-118-018&depa=0
http://www.lsilogic.com/products/scsi_hbas/lsi21320_r.html (LSI's own product page)
Isn't it nice when careful evaluation of what you want turns up with exactly the stuff you'd originally thrown an eye on? 🙂
 
The LSI 2x320R controllers do the RAID business inside the SCSI processor alright. This isn't host CPU based el-cheapo RAID either!

http://www.lsilogic.com/files/docs/mark...Technology/Integrated_Raid_Handout.pdf

Big guns like that Mylex will do hardware RAID5, using a separate RISC processor that coordinates multiple SCSI processors on a local bus, megabytes of local RAM storage, and a large amount of your money. Not Needed Here.

And yes, Atlas 10K IV drives are fast enough to be limited by U2 bus interface, even if it's just one single drive per channel.
 
You must log in or register to reply here.

TRENDING THREADS

Back
Top