SCSI vs. IDE/UDMA...Why pay more?

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drjay

New Member
Hey guys, been building up my system a bit and I'm running into instances where I need to edit upwards of 225,000 files, 2-8gig, all in one folder. My current drive setup just isn't cutting it and I'd like to upgrade a bit but I'm wondering if it's going to be worth it.

I was just reading a bit in the HDD 101 thread and seeing as my current PCI system is limited to 133m/sec and so is UDMA Mode 6, why pay extra for a scsi controller and HD? I've benchmarked my file system and I'm getting just under 40meg/sec and I believe it's set to UDMA5, at least according to Windows. Slower than spec on that, but then again I doubt I'll honestly see 133m/sec even with a scsi drive.

In anycase I'm looking at the Maxtor Atlas 15K 18GB Ultra-320 SCSI Hard Drive and, as a secondary question, am wondering what the fastest I could expect from this considering I don't have a pci-x slot. First really, can I run an ultra-320 HD without an ultra-320 interface plugged into a pci-x slot? IIRC that would limit me to 160m/sec, but further limit me to 133m/sec, but then further probably only realize <??>m/sec.

Sorry for all the questions, I've never really wandered away from IDE.
 
Cromewell

Cromewell

Administrator
Staff member
That Atlas should get upwards of 66MB/s but you're right, no drive will even approach the transfer rate limit.
 
Modoman

Modoman

New Member
scsi is the fastest interface for hd am i correct? not to mention the most expensive... 15k rpm 150gb scsi is like $1200
 
Cromewell

Cromewell

Administrator
Staff member
True, I wouldn't recommend SCSI for a home user. I probably have taken your post out of context, I thought you were saying a SATA drive would get close to the spec limit.
 
Chris Chan

Chris Chan

New Member
I'd not recommend SCSI either, get a Western Dig WD2500KS. Sata2 and benchmarked to have best speed out of all drives Maximum PC magazine has tested iirc.
 
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drjay

New Member
Ahh thanks for the responses so far. The computer I have is only a "home computer" because of location. It's really a workhorse for me. It's a P4 2.8 with 4 gigs of pc3200 and about 350 gigs of HD space but no video card to speak of. I use it for all my business related needs and the AMD 2.0 next to it for any 'home' computer needs.

I really only need to access about 8 gig of files but I need it to be incredibly fast. I thought a good 15k rpm SCSI drive would do the trick but if Cromewell is right I'm already decently close to the 66meg/sec to not really bother. I'm open to spend $4-600 on a hard drive solution and would settle for only 10gig of space if it could transfer at 100meg/sec or faster. Is there something like this out there or is this all just a pipe dream? I recall some time back when I benchmarked mine there was an option to compare it to others. I saw a few that seemed to crack the 100meg mark but who knows what they did to get it.

Thanks again!
 
Cromewell

Cromewell

Administrator
Staff member
Where you see >100MB/s you could be seeing the end result of RAIDing, where that speed is spread across multiple harddrives
 
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drjay

New Member
yeah I'm vaguely familiar with the RAID setup. I've considered it but wasn't sure if just one powerful arse HD would be able to match it. In that case, would it be possible to set up a RAID system with 2 of the scsi atlas 15k hd's? Potentially doubling the speed, correct? Or is RAID an ATA thing only?
 
Cromewell

Cromewell

Administrator
Staff member
No, RAID works with SCSI, it wont double the speed but it will make the net result faster. A SCSI RAID would be very expensive, SATA/PATA is more economical and will be fairly fast.
 
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drjay

New Member
Thanks for keeping with me on this.

I'm not quite as concerned with being economical as I am about getting maximum performance. You somewhat contradicted yourself so I'm a little curious. Is a SCSI raid system not possible, or just expensive? I'm barely grasping it but as I understand it there is a 'software raid' setup that's possible. Heard it's not as fast as a hardware raid, but it's faster than nothing. Would it be possible to get two SCSI HD's and do a software RAID setup? Could I get 100meg/sec+ from something like that?

I'm going to get something along those lines and I"ll be happy to post benchmark tests for those that might be curious about the setup. Thanks again.
 
jesbax

jesbax

New Member
with the right software/ hardware you can set up a scsi raid. that is how the big severs work by useing a scsi raid to turn a bunce of small hdds in to one big one. with one card you can hook up at least 7 devise to card. some cards can have up to 15 devices on them. in the mid to late '90s mac used only scsis in the computers. with introducion of the imac is when they started to go with ide. scsi has a trasfer rate of 400MB/sec. Lot of servers use scsi instead of ide becuase of its fast tranfer rate. scsi also has the largest hdd out on the market. 8 years ago you could pick up a 500GB scsi hdd for about $1300. ther was one sever that i worked on which the company had that they used for a file server and it had 15 hdds in it with close to 800gb of storage space on it and at the time that was a lot of storage. now 800Gb is just child's play. but any way scsi raid is very posible and is done that way on most network servers.

edit: i do have a 15 device scsi raid card out of an old server. it does require an iso slot to use it.
 
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Cromewell

Cromewell

Administrator
Staff member
Sorry that was contradiction was unintentional, I'm missing a comma :eek:

As long as you are buying a SCSI card you migth as well get one with hardware RAID
 
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drjay

New Member
jesbax said:
with the right software/ hardware you can set up a scsi raid. that is how the big severs work by useing a scsi raid to turn a bunce of small hdds in to one big one. with one card you can hook up at least 7 devise to card. some cards can have up to 15 devices on them. in the mid to late '90s mac used only scsis in the computers. with introducion of the imac is when they started to go with ide. scsi has a trasfer rate of 400MB/sec. Lot of servers use scsi instead of ide becuase of its fast tranfer rate. scsi also has the largest hdd out on the market. 8 years ago you could pick up a 500GB scsi hdd for about $1300. ther was one sever that i worked on which the company had that they used for a file server and it had 15 hdds in it with close to 800gb of storage space on it and at the time that was a lot of storage. now 800Gb is just child's play. but any way scsi raid is very posible and is done that way on most network servers.

edit: i do have a 15 device scsi raid card out of an old server. it does require an iso slot to use it.
Click to expand...


400MB/sec sounds right up my alley. But then, aren't I limited to 133mb/sec by the pci bus? Either way sounds like a hardware SCSI raid system is what I'm after. Since I don't have an ISA slot I'm off to price some upgrades! Thanks again and please let me know if there's anything I'm missing with this :D
 
jesbax

jesbax

New Member
im glad to shed some light on it for you. now if i can find a computer that can use it.:rolleyes: plus i have about 30 scsi hdds with the biggest at 1.3GB and the smallest 40MB.
 
randruff

randruff

New Member
If you want to go with a more economical approach, invest in two WD Raptor 10,000rpm drives and run them in RAID 0. That is what I have for my current setup and it is EXTREMELY fast. I'll give you a couple examples for reference and these are all true, no exhaduration...

-Windows Installation (point right after HDD format, instal gui says "initializing installation" or something like that to when you're in Windows): 12-13 minutes.
-Service Pack 2 Installation, begining to end: about 5 minutes
-Average scan time for 72gigs of data (out of about 135) with MS-Antispyware: 2 min 50 sec.

Hope these help.
 
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