SCSI or DMA100???

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A friend of mine has an IBM ultrastar 9.1 gig Ultra Wide SCSI drive and Adaptec AHA-2940. He said he would sell it to me for a ballpark of $100. My question is: would an ATA-100 drive outperform that? Which do you think is more cost effective? I already have ATA-100 controllers on my board, so I wouldn't have to buy that. I am running a 30.6 gig Seagate ATA-66 drive right now that is constantly fillng up. I was thinking of getting another drive to load my OSes on that would be faster and boost my overall performance. Tell me what you think, and thanks!!! = )
 

LTJLover

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SCSI is faster than IDE eventhough now a days new IDE devices are closing the gap. I have never felt the need to deal with SCSI because they are a bit more involved to deal with. The cables need to be terminated in a special way, the controller card is separate, things like that. It is up to you if you want to try somehting new or not. SCSI is more $$$ than simple IDE stuff. Sounds like that 9gig might not be enough for you anyways. For a little more than 100 bucks you can get a 30-45 gig IBM ATA100 drive. If you want some super hard drive action, pick up a RAID controller and RAID up a few IDE drives. Good luck.

Jon
"Water-Cooled CPU Runner"
 
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I have had experience with this exact thing, except my SCSI drive was a Seagate Cheetah 9.1Gb, 10k rpm Ultra Wide. The SCSI will definitely seek faster, meaning that you could possibly start doing something with the data faster, plus is multiple things are happening on the SCSI drive at the same time, the SCSI will finish faster, but that perticular IBM drive will not perform better that the latest IDE drives on the market. A couple of drives stick out that will perform better, the IBM 75GXP's, WD400BB, Seagate ST340824A 40Gb. The reason they will perform better in most cases is density. The IBM SCSI drive in question probably has 4 or 5 platters, containing at most 2.2Gb's per platter, the IBM 75Gxp's have 15Gb per platter, the Seagate and WD drives have 20Gb per platter. Why this is better is that the drive does not have to moves the drive heads all the way across the drive, plus the data is more tightly packed on the platter. The newest SCSI drives have at most 10gb per platter, operate in the 10k to 12k rpm's with 4mb to 8mb of cache on a SCSI 160 setup. The problem with these, COST!!! Spend the $100.00 on a new drive. You can get a IBM 46.1Gb 75GXP model for $149.00 on Mwave.com.

<P ID="edit"><FONT SIZE=-1><EM>Edited by kn7671 on 01/03/01 03:24 PM.</EM></FONT></P>
 
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Thanks for all your help, guys. I get a lot of mixed answers on this one. I thnk that I am more concerned about how the drive performs than anything else. Sure, I have filled up a 30 gig drive already( edu connection : ) ), but I can always burn off junk. What I want is a drive that I can put my OSes on for really fast access, and then a massive drive (30 gig ) to store all my crap. I currently have both OSes (win98 & 2k) on their own partitions so I can format anytime I want. So how do they stack up, pure performance??
 
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Depending on which 9.1 ultrastar (as that is there server line of drives and just about every model has been released in a 9G flavor since 9G drives have been around), it may or may not have a seek time performance comparable to the newer 75GXP IDE models. I don't think any of their 9.1G ultrastar drives (unless it happens to be a 73LXP 9G flavor which I doubt) have sustained rates that'll beat that of the 75GXP although their newer 9.1G models have better seek times and I guarantee you it will outperform the newer IDE drive in some areas where sustained transfer is far less important (like just the average use of the system on a daily basis). But still..it's only 9G. So if it happens to be one of these newer models, the Gig per buck just doesn't matter to you, and that tiny increase in seek time compared to a 75GXP ..we are talkin 2-3 ms on average is worth it, sure. But it's probably not one of the newer 9G models and therefore not worth the 100$ (even with the card which is probably just an UW) since for a little more you can purchase an IDE 75GXP that's twice the size, a better performer, and unused! True that SCSI drives can handle IO better than IDE, which is important on a average day to day usage of the machine.. And though I've read in reviews where benchmarks showed older SCSI drives (old 7200 drives) even beat out newer IDE drives in this area, I doubt that shows in real performance. Moreover you probably can get better performance than top of the line IDE of the day, but to do that you undoubtedly have to buy top of the line SCSI drives of the day, which is not the case here.

***Hey I run Intel... but let's get real***
 
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Exactly, at what expense would one have to layout to get a SCSI drive that can perform as well as the newest IDE drives, around 5:1, so if you spend $200 for the IDE drive, expect to spend $1000 for the SCSI drive and Controller card. Not worth it at all! If all you had was $1000.00, you could buy the newest IDE drive every year for 5 years, or be stuck with the SCSI setup for 5 years. Your choice. If you got money to burn, than get the SCSI, be prepared for the noise, and expect to cool those 10,000rpm drives in some way, but the performance will not sustain better than IDE drives for long, because something better is right around the corner.
 
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Yeah.. I sometimes kick myself for setting up SCSI because it is quite an investment for minimal or no gains on a desktop system when looking at how IDE has improved today. Maybe not $1000 dollars but somewhere between there and $500 dollars for a high end scsi drive and controller with far less Gig. I guess if you add in moving other drives you want on the bus it could easily hit over a $1000. Oh maybe there is a part of me that gets some Tim "The ToolMan" Taylor kind of pleasure having all my drive, removable, etc running off their own 32 bit synchronous bus as opposed to the the typic 16 bit ISA IDE channel. But with today's add-on or integrated controllers running off the PCI bus and handling DMA on the card (opposed to Southbridge+OS combo) and the improving performance of the drives (all of which was not quite where it is today when I setup my home system on SCSI), it's just not worth it unless you got more money than brains.

SCSI still and remains to shine the best where it belongs. On the Server with multiple drives and multiple controllers handling high IO traffic.



***Hey I run Intel... but let's get real***
 

rcf84

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hmmm i just got ibm 9.1gb scsi3 harddrive. well if you have nt4 or win2000 get scsi cause "scsi and ntfs are a good combo". if you have 95 or 98 or ME get IDE. very simple.

note linux users get scsi

ATI RADEON 32MB DDR RULE!!!!!!!!!!!!!!!!
 

jstoorvo

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Another option: use 2 deskstars and a raid controller for striping. Is very cheap. You'll still be stuck with the 'slower' access time of the IDE disks, but for streaming, this is really fast. SCSI disks are too expensive
 

WildRhino

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This is one of the most laughable posts that I have raed so far.

I've had a Fujitsu MAG3182 10k SCSI, it needed no extra cooling and it's performance was first rate.

There will always be "something better is right around the corner", all the time so don't listen to this nonsense.
 
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With the new 7200 rpm drives that are out , the scuzzy is still faster, but marginally, scsi as people have said is a little more complicated, but terminating it is easy, you require terminators at each end, thats all, I guess you have to consider also where scsi technology is going, is it still being developed, ultra wide has been around for a while now, dont want to get stuck with old technology.

Life is a lesson, You learn it when youre through
 

Crashman

Polypheme
Editor
Ultra Wide is 50 pin right? That is an old standard, I believe it only supports 10MB/s. The 2940 is the cheaper version of the 2940UW, which supports up to 40MB/s. So $100 is a good deal to someone who needs it but not to someone who doesn't. Go ATA100

Suicide is painless...........
 
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>>but terminating it is easy<<

Of the majority of problems I've seen, termination is one of the leading causes of an ill-behaved SCSI bus.

>>I guess you have to consider also where scsi technology is going, is it still being developed, ultra wide has been around for a while now, dont want to get stuck with old technology.<<

SCSI is not going anywhere and certainly is still being developed. Ultra technology isn't the latest development in SCSI.

Again with SCSI drives using more discs, therefore more heads, and along with 10k spindle speeds. Even the older drives will offer a performance that feels faster (by small margins) in day to day operation. Though as well since the density on them is generally less, they don't have the higher STR of recent IDE drives (not a big deal with RAID arrays). You have to pay for it in any fashion though even if it's only for the higher access times. Even the fujitsu mentioned is still 2-3x as much as a relative sized IBM 75GXP. And a fairly hefty priced controller. If you want one that has improved STR along with the access times, you have to pay even more. It's all minimal gain for the price but that's probably relative as some are willing pay for the small benefit.


***Hey I run Intel... but let's get real***
 
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>>Ultra Wide is 50 pin right?<<

No. It's 68 pin. (ALL wide interface is 68pin)

>>That is an old standard, I believe it only supports 10MB/s<<

No it supports 40MB/s, and it is still used heavily with removable media drives and other periphs. It's old technology for hard drives though.

>>The 2940 is the cheaper version of the 2940UW, which supports up to 40MB/s<<

The 2940 supports up to 20MB/s using Ultra Narrow. The 2940UW (Ultra Wide) does support up to 40MB/s off the 68 pin (WIDE) connector and up to 20MB/s off the 50pin (NARROW) connector.




***Hey I run Intel... but let's get real***
 

Crashman

Polypheme
Editor
Forget the whole wide/narrow thing, the 2940 has 50 pin SCSI 2 connections only-I should know, I have one. I quit using it because I needed a 68-pin interface, so I now use a 2940UW. That's right, I have both cards, one is in use and the other is not. So at any rate the 2940 is limited by the spec of it's 50-pin SCSI interfaces.

Suicide is painless...........
 

Crashman

Polypheme
Editor
BTW, my Vendors refer to Ultra-Wide SCSI when specing 68 pin, Wide SCSI when refering to 50 pin standard internal cables, and Narrow SCSI when refering to the SCSI2 HD cable. Of coarse that means that an Ultra Wide drive would have to run an adapter to be connected to a 2940, and would therfor be limited to SCSI2 performance.

Suicide is painless...........
 
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...that sounds like the "God Box" over at Ars, but they've gone all the way and RAIDed the SCSI. Get yer wallet out...

<font color=blue>http://arstechnica.com/guide/system/godbox.html</font color=blue>
 
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Your vendor is wrong..

50pin internal SCSI cables only allow for 1 byte (8bit) bus.. (thus a narrow designator).. 68pin internal cables allow for a 2 byte (16bit) bus thus the WIDE designator. This a defined SCSI standard.

50pin internal and 50pin HD external are both narrow cables, because they only allow for 8bit bus.


***Hey I run Intel... but let's get real***
 

Crashman

Polypheme
Editor
That still validates my reasoning that the 2940 would perform much more slowely than an Ultra ATA 100. The 2940 only supports 50-pin (SCSI2) transfer rates, because it only has 50-pin interfaces.

Suicide is painless...........
 
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no doubt about that...

but that wasn't my point. I'm just trying to depetuate the confusion with SCSI.. cause it's basically simple when you understand the standard. Hard to do that when narrow is confused with wide.. and Ultra Wide is said to have 10MB/s and 50 pin, which is not the case. Ultra (SE) clearly defines it as a 20Mhz bus.. Wide clearly defines it at 2 bytes therefore it has to be 68pin with a max of 40 MB/s.

The 2940 itself is probably best left for scanners or CD media drives. I agree with that, but then again, most people willing to spend 500$ for an LVD hd won't even be considering a 2940UW much less the 2940. So they are really irrelevant to a SCSI hd comparison here.



***Hey I run Intel... but let's get real***
 

Crashman

Polypheme
Editor
At the current sustained transfer rates (between 31 and 36 MB/s for ATA 100 drives), I believe that the 2940UW with a good drive can hold it's own against a UDMA 100 drive+interface. In fact it may actually perform better if you are accessing 2 or more drive sumultaneously. But not the 2940 standard such as the one in question. So that should answer his question completely.

Suicide is painless...........
 

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