IBM 34L7702 SCSI Hard Drives 1

[skildner1]

I have a bunch of these hard drives. They were pulled from an old server. They are 9.1GB each. I was wondering if I could get a SCSI Card and run 4 of these in a RAID 0 Array. I also wonder how my computer would/could power these hard drives. Besides the part number of 34L7702, the only other numbers I see on the drives are: DMVC IEC COMP-950. Any help would be appreciated.

 

[wahnula]

The answer is yes, but you would not only need a SCSI controller card, it would have to be a RAID controller card as well. That could get expensive, and the dollar/GB ratio is pretty bad, as with all 4 drives (which only draw about 25 watts-30 watts each) you're looking at ~30 GB. And spending a lot on a controller/RAID card would commit you to that interface as the drives fail. Now SCSI is wonderful, don't get me wrong, but it's meant for servers and many of the cards are PCI-X 64 bit. Plus, these drives are old and will fail.

I would buy an old Adaptec 2940

http://www.gearxs.com/gearxs/product_info.php?products_id=2306

and play with the drives individually; you will see that a 10K SCSI drive many times is as fast as a slower IDE RAID 0 setup. Use one for XP, one for Linux, one for Win98, etc., and a sub-$100 ginormous IDE or SATA drive for data.

Have fun, but don't invest a lot in these drives.

Tony

 

[skildner1]

Wow, thank you for the thorough answer. I have a couple of options at the moment. I figured I could get 3 160GB hard drives and run them in a RAID 0 Array for about the same price as a 160GB Raptor. Then I remembered that I have these sitting around. Would it be worth it to try and make use of these, get a Raptor or get the 3 WD1600YS 160gb hard drives. I do a lot of gaming on the computer so performance really matters.

Thanx in advance,

Yona

 

[wahnula]

Just remember for every RAID 0 array that you have, you MUST have a backup drive equal to or greater than the size of the array. This is because RAID 0 has NO resiliency or fault tolerance. My choice for a RAID 0 is smaller, faster hard drives like 36 or 74 GB Raptors that keep the data close together. If you stripe (3) 160 GB drives w/o partitioning them first you could end up with a performance drop, as data is strewn from the outside edge (fastest) to the inside edge (slowest) of the platters. In my world RAID 0 arrays are used for OS and apps, and other things I have CDs for, unless they are backed up at least once daily.

Nowadays the 7200 SATA drives are are closing in on the Raptors, but at $100 each if I were building a machine for speed I'd take two smaller Raptors for the RAID 0 array, plus a $100 400-500 GB SATA II or more for data.

Tony

 

[skildner1]

I think your solution sounds best. I can get 2 36.7gb Raptors and run them in a RAID array. I've given up on the 9.1GB SCSI drives, but I am now intrigued with the SCSI interface. Why do we not use it? Why have we switched to SATA or even IDE for that matter which was much slower than SCSI when it first came out? Also 15000RPM SCSI Ultra160 or even Ultra320 drives are available for relatively cheap nowadays. Why not use those? Or better yet set a few of those up in a RAID array (I know a SCSI RAID controller card is expensive, but the drives themselves are so cheap and so incredibly fast). I'm just curious. Perhaps it would be more economical for me to get a SCSI controller card and a 15000RPM SCSI hard drive to use as my Windows drive.

Thanx again,

Yona

 

[wahnula]

Why have we switched to SATA or even IDE for that matter which was much slower than SCSI when it first came out?

Great question. The main reason is/was cost. SCSI drives are built like tanks and initially the price difference between them and consumer-grade IDE drives was stiff. Plus the IDE bus was capable of handling ATAPI devices, so that one's easy.

Fast-forward ahead to SATA. A serial transmission protocol unlike SCSI (parallel) but without the strict manufacturing standards set by ANSI for SCSI. Also, implementation was easier, as you did not need to number each device and terminate the bus, nor set up master/slave scenarios.

It was also simple for manufacturers to change the backplane and PCB and use IDE drives for SATA. Hot-swapping was now possible too.

Many people still swear by SCSI, as do I for servers (all I will use), but they add a level of complexity (and noise) to provide a more durable and robust interface. Most consumers want things easy and cheap, and that's SATA.

I'm glad you're pursuing this, knowledge is a good thing and SCSI is a professional bus, plus it's fun to say.

Tony

 

[wahnula]

For further reading:

http://www.pcguide.com/ref/hdd/if/scsi/index.htm

 

[wahnula]

One more note if you do decide to get a SCSI RAID controller and play in the SCSI sandbox then two of those drives in your possession should be all you need for a RAID 0 OS array. I would keep the others for spares.

Tony