SCSI vs ide HD's

[edhensley]

Ok, i need to find information about the benifits of scsi vs ide hd's. I got a department trying to spend too much on workstations due to their belief that scsi hd's are better than ide hd's.

Personal I know that there is very little difference unless you count that you can chain drives together. But I need 3rd party information to save $$$ so I can spend more on additional machines.

Arguement is:

1) that scsi HD are more stable.

2) that scsi HD have a longer MTBF

3) that scsi HD are more compatible with scsi tape drives

The systems are used to push data to tapes and carts.

Damn scsi drives are expensive and smaller. Just can't see how ide hd will negatively impact their operations.



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If Compaq can build a computer then anyone can

[GHz]

Depends on what these workstations are for. Seeing that they are workstations you will probably be better off with SCSI as I guess you will be using programs that will acess the HD a lot. SCSI has no real use in a home PC as people using home PCs do not acess there HD and move or work with large files where the HD is constantly busy. Some might say what about games? Well games dont constantly acess the HD because once a level is loaded into memory it no longer needs to transfer files from the HD. But if you plan on doing stuff like video/audio editing or plan on working with large files I would suggest SCSI. If not IDE is good enough.

[gaffo]

I hate IDE, but I don't need SCSI due to slow cpu and no video editing. But if you have to do audio/video or a lot of multi-tasking, then SCSI is lightyears ahead of IDE. Sure as hell my next system will be SCSI (not crappy/kludgy IDE crap ). But if your workstations are not for video - get IDE drives (cheaaper and no SCSI card needed).

[SkyDog]

It all boils down to a decision on whether the extra performance is worth the price. SCSI really is better than IDE in many ways, especially when transferring a lot of data or using multiple devices.

Anyway, they're pretty much right in two out of three of their arguments:

2) SCSI drives do generally have a higher MTBF, especially the drives aimed at the server and high-end workstation markets. Somewhere around here, I've got a couple old Micropolis 1 GB drives made in something like 1987. If that date's right, that means they were in a server running 24/7 for about 10 years!

3) In reference to working with a SCSI tape drive, I might not use the words "more compatible," but a SCSI hard drive would be a hell of a lot more efficient. For starters, data could essentially move straight from the SCSI hard drive to the SCSI tape drive, never having to leave the SCSI bus. And the SCSI controller could handle this without much CPU intervention. With an IDE drive, the data would have to be moved from the IDE drive to system memory via the IDE controller, then moved via the PCI bus to the SCSI bus, and finally to the SCSI tape drive. IDE on its own is somewhat more CPU-dependent than SCSI, even without moving data from one bus to another to another.

[nick1983]

Ofcourse SCSI is still more stable and faster then IDE. But also much and much more expensiver then IDE! I would recommend a 7200 rpm harddrive from IBM. The best IDE-harddrives in the world! But if you work with highly advanced 3d programs (like Lightwave) then it is better to use SCSI-drives (because of their faster rpm 10000).
But I would self never buy SCSI-drives!

[100%TotallyNude]

Originally posted by nick1983:
Ofcourse SCSI is still more stable and faster then IDE...
<snipparoo>
But I would self never buy SCSI-drives!

Your not making any sense. Why in the world wouldn't you buy something more reliable?

Hres my take/experience: 1) SCSI drives are more expensive, but no THAT much more. 2) In IDE's court, I don't know that they are any more reliable than SCSI's today. I use ATA/66's in my main workstation and they seem fine for what I do. 3) SCSI I/O systems have tended in the past for me to be easier to configure, and even to the present. I just put a a new 20Meg WD ATA/100 in my wife's old non-ATA mode board becuase thats all that was available on the shelf, not that is should have mattered, but to get the thing active I had to run WD's included software, which for some reason insisted on backing up the existing data on the old drive, and the software errored out on doing that. Finnally I ended up with a 10 Meg drive. What happened to the other 10 Megs??? Now I have to sit down tonight and figure out what the deal is with this drive that did a back up of the old drive that I didn't want it to do in the first place and find the missing 10 Megs.

This wouldn't happen with a SCSI drive. I guarantee it. You slap the drive in to an empty slot in the chain, and boom, its there. No mess no fess.


[This message has been edited by 100%TotallyNude (edited November 20, 2000).]

[nick1983]

I said: SCSI-drives are more reliable then IDE-drives, but in the Netherlands they arent such cheap! If I had more money I would buy definitely a SCSI-drive! But you know, no money! Although I prefer IDE-drives (only from IBM, and 7200 rpm)

[100%TotallyNude]

Originally posted by nick1983:
I said: SCSI-drives are more reliable then IDE-drives, but in the Netherlands they arent such cheap! If I had more money I would buy definitely a SCSI-drive! But you know, no money! Although I prefer IDE-drives (only from IBM, and 7200 rpm)

No you didn't. The quote is right up there. You didn't mention a thing about the Netherlands. So nyah.

[nukefault]

Originally posted by 100%TotallyNude:
Your not making any sense. Why in the world wouldn't you buy something more reliable?

Hres my take/experience: 1) SCSI drives are more expensive, but no THAT much more. 2) In IDE's court, I don't know that they are any more reliable than SCSI's today. I use ATA/66's in my main workstation and they seem fine for what I do. 3) SCSI I/O systems have tended in the past for me to be easier to configure, and even to the present. I just put a a new 20Meg WD ATA/100 in my wife's old non-ATA mode board becuase thats all that was available on the shelf, not that is should have mattered, but to get the thing active I had to run WD's included software, which for some reason insisted on backing up the existing data on the old drive, and the software errored out on doing that. Finnally I ended up with a 10 Meg drive. What happened to the other 10 Megs??? Now I have to sit down tonight and figure out what the deal is with this drive that did a back up of the old drive that I didn't want it to do in the first place and find the missing 10 Megs.

This wouldn't happen with a SCSI drive. I guarantee it. You slap the drive in to an empty slot in the chain, and boom, its there. No mess no fess.


[This message has been edited by 100%TotallyNude (edited November 20, 2000).]

1. SCSI is like twice as expensive as IDE, not even including the extra controller card. You can buy a 20GB 7200rpm ATA100 IDE drive for like $140 or less on www.pricewatch.com...SCSI may be better, but you pay for it. I myself use quad 30GB ATA100 7200rpm IBM Deskstars and sure its slower than Ultra160 SCSI, but still not too shabby and I paid under $600 for it. How much can you build a 120GB SCSI setup for? $1400?

The problem with your computer is probably that older systems have max partition sizes that really aren't sufficient anymore. A friend of mine just got a 30GB ATA100 drive and couldn't format each partition for more than 16GB on his old HP. Not the IDEs fault


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"It is better to keep your mouth closed and look stupid, than to open it and remove all doubt."

~Famous Dead Guy

[oddlycalm]

Workstations for business use can't be evaluated in the same manner as a single user home machine. Thus far everyone has focused on price. In business, one needs to focus on cost, of which purchase price is but a single component.

All the arguements given by the department are correct. In this particular application, if I understand it correctly, heavy use will be made of the storage subsystem. There should be no question about whether to buy SCSI drives. That fact that you are questioning it allows one to wonder whether your experience is sufficient for you to make a good decision on purchase of these workstations. The giveaway is that you state that you have personal knowledge that there is very little difference unless multiple drives are employed. I won't delve into the specifics of the differences between the construction of the best IDE drives vs enterprise level SCSI drives, but they are most definately not the same.

Justification:

The tape drives will require SCSI host adaptors, so you have that expense in any regadless.

HDD to tape drive interaction will be improved. As I assume that such workstations will be using Win2K or NT 4, you will be able to take advantage of the superior connect / disconnect functions SCSI offers in a multi tasking environment. While sustained data transfer rates may be similar, access time is most definatly faster for the SCSI devices. The above will result in consistent incremental superiority in time per task, which add up to lower costs when calculated across multiple workstations throughout their service life. The difference is quite significant over the life of multiple workstations.

Reliability of the SCSI HDD's is superior. The downtime, and cost of servicing just one workstation with a dead drive, will probably obliterate the price difference between the SCSI and IDE devices.

To summarize, your reasoning is correct if a single user home environment was the excercise, however it is not. Workstations in a business environment is a different application altogether, and the hardware should reflect those differences.

oc

ps As we are venders to all the drive mfg's, I can supply the specific differences in the mechanical parts employed in both the IDE and SCSI devices, but you shouldn't have to look beyond sound level and access times to realize that something very different is occurring in these two different classes of device.