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scsi hard drives

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August 30, 2002 2:34:04 PM

i have just bought a seagate cheetah 18.2gig scsi hard drive and a Advansys adaptor card from ebay, for which i have paid £70 for the two items.
now i believed that scsi was a lot faster than ide, but i was proved wrong..
when i benchmarked the drive, the score for the drive was 15,000 in sandra 2002 for the scsi and 30,000 for the ide ibm ide drive i have.
the scsi drive spins at 10k, is a 50pin drive (if that makes any difference) and is getting rather red hot too..
firstly, is this drive connected and setup correctly? and if so, why is it half the performance of a ata 100 7200rpm ide drive?
im new to scsi drives and it has seemed to have 'gone in' perfectly and easy.. the only thing im not sure about is the termination side of things..
as far as i know, im not sure whether or not i need to have it terminated or not, or whether its self terminating.
please could someone help me, as this is the first scsi drive i have had, and so far not that impressed with its performance.
thanks for any help guys and gals..

if all else fails... kick it and if it goes wrong, say it wasnt you...

More about : scsi hard drives

August 30, 2002 3:16:10 PM

just found some more information about the card / hard drive etc..
the model on the card says Advansys ABP-940/70UW68
the model of the hard drive is seagate cheetah st118202lc..

if anyone can enlighten me, i would be most appreaited..
thank you all

if all else fails... kick it and if it goes wrong, say it wasnt you...
August 30, 2002 10:04:29 PM

For one you are comparing a new generation Ide drive to a Scsi drive that is several generations old...hardly apples to apples. Just because it is SCSI in and of itself does not make it faster.

It's not what they tell you, its what they don't tell you!
Related resources
August 31, 2002 12:22:56 AM

im having problems with my drive now..
i have low level formatted the drive and when i come to fdisk the drive, it comes up with no space to create a dos partition.. why is this happening?
there are no other partitions on the drive, the drive is completely emtpy and its still not allowing me to partition the drive.
i wasnt sure whether or not the drive was brand spanking new, but if i bought a brand new scsi drive, be it a seagate or what have you, what would the performance be like compaired to what i have now? ie the obm 80 7200 ata100 drive i use...
please help me this is driving me mental...

if all else fails... kick it and if it goes wrong, say it wasnt you...
August 31, 2002 1:34:27 AM

Quote:
i wasnt sure whether or not the drive was brand spanking new, but if i bought a brand new scsi drive, be it a seagate or what have you, what would the performance be like compaired to what i have now?


It all depends on what drive you are talking. The latest and greatest Scsi drive that is about to hit the market ( 3rd gen seagate 15k) has a sustained transfer rate of 79,000 KB/s. Yes sports fans it lays waste to the WD JB.

It's not what they tell you, its what they don't tell you!<P ID="edit"><FONT SIZE=-1><EM>Edited by ncogneto on 08/30/02 09:35 PM.</EM></FONT></P>
August 31, 2002 1:35:48 AM

First here is some helpful information about FDISK, FORMAT and other troubleshooting tip <A HREF="http://www.compguystechweb.com/troubleshooting/hardware..." target="_new">HDD Troubleshooting</A> I also, suggest you read the articles in this sector’s <A HREF="http://forumz.tomshardware.com/hardware/modules.php?nam..." target="_new">FAQ</A> in regards to SCSI. Very helpful info there.

The HDD you have <A HREF="http://www.seagate.com/support/kb/disc/howto/interpret_..." target="_new">ST118202LC</A> is rated at 80 Mb/sec transfer rate, the LC means that it is an 80 pin SCA drive, so you have a 68 pin adapter to run it or else you have a SCA backplane. The cable you should be using is LVD 68 pin with terminator (not the 68 pin Ultra2), it should be printed on the cable end connector going to the controller card. Make sure you are using the correct cable.

I could not find a match to the model #: <A HREF="http://www.advansys.com/products/index.htm" target="_new"> Advansys ABP-940/70UW68</A> you mentioned. What is the transfer rating of that card? Are you sure it is not 20 Mb/sec? If that is the case, then your HDD will default to the controller’s bus transfer rate.

Also, since that is an older card, make sure the BIOS are current. I remember you were considering a different setup, so if you card is under rated in comparison to your HDD you may wish to consider updating the card. Although, I maybe wrong because I couldn’t find the spec’s on that card.

Yes I also recommend Seagate seatools. Good luck.

<font color=purple><b>Listen twice as much as you Speak. Better yet, Think twice. :wink: </font color=purple></b>
August 31, 2002 9:22:22 AM

hi and thanks for all the information..
i have it connected using a 50 pin cable. the card supports a 68 pin connector as well but the cable wasnt supplied. i have a small 'board' that connects into the back of the drive that converts it from a 68pin to a 50pin connection.. could this be why it seems a little slow?
the model advansys card i have been supplied with is called a ABP-970UA & a ABP-970UW-68. i believe it to be for the mac, as it has mac installation help as supposed to a windows help.
im not sure on what the card is, but the hard drive seems to be fast enough at 80mb/sec so you say!!! but im sure that the card is holding back the drive, so im lead to believe.
i picked the card and the drive for £70, i thought it was a bargin, but its just slowly turning into a nightmare!!

i have since then low level formatted the drive and its coming up with a problem saying that there is no space for dos partition. its just been low level formatted and theres no space, rightttttttttttt. anyway, i have downloaded a various amount of tools from seagate.com all they dont seem to have done any good. i have used discwizard 2002 which seemed to have done something, but when i was trying to partition it, it just kept coming up with the same problem as before, ie theres no space for dos partition.
please can someone help me?????

if all else fails... kick it and if it goes wrong, say it wasnt you...
August 31, 2002 2:38:53 PM

Quote:
The HDD you have ST118202LC is rated at 80 Mb/sec transfer rate


You should clarify this comment. The drive he is using uses a 80 MB/s interface. That does not mean it will transfer at 80 MB/s not on a good day down hill with an 80 mph backwind. Much like an IDE ata 100 drive will not transfer at 100 MB/s. This drive will at best transfer at around 25,000 KB/s.

I too have had simular difficutly cross referencing the card he mentions

It's not what they tell you, its what they don't tell you!
August 31, 2002 2:58:20 PM

At this moment you have nothing to loose, so with Seagate's DiscWizard 2002 try to Low-Level format the drive again, then let DiscWizard FDISK & Format the drive with it's diagnostic utilies. Hopefully, this will correct the error. <A HREF="http://www.ameriwebs.net/groupworks/george/llf.htm" target="_new">more info</A> I hope you get things turned around.

Yes, the SCSI Controller card and the 50 pin (Narrow-SCSI) adapter is the cause of you 80 pin HDD to under perform. You need a (Wide-SCSI) <A HREF="http://www.starmount.co.uk/sca_2.htm" target="_new">SCA adapter</A>, with <A HREF="http://store.yahoo.com/directron/ultra160.html" target="_new">68 pin LVD Ultra160/320 68 pin cable</A> (not the Ultra2 68 pin cable), then a better affordable choice would be an <A HREF="http://search.ebay.com/search/search.dll?cgiurl=http://..." target="_new">Adaptec 2940U2W SCSI Controller Card</A> or <A HREF="http://www.axiontech.com/quicksell/moreinfo.asp?prdtcod..." target="_new">retail OEM</A> (connector on it: 68-pin LVD-80 Mb/sec, 68-pin wide-40 Mb/sec, & 50-pin narrow-20 Mb/sec), three seperate SCSI buses for backward compatibility. Update the BIOS of you M/B & SCSI Controller if necessary, and thing will be better.

<font color=purple><b>Listen twice as much as you Speak. Better yet, Think twice. :wink: </font color=purple></b>
August 31, 2002 3:12:08 PM

Ok, to clarify the 80 Mb/sec tranfer rate; means that the HDD is capabale of 80 Mb/sec under the conditions that the HDD is configured with compatible interface hardware (SCSI Controller, proper Cable on an independent SCSI bus, and an optimized HDD, i.e., optimum size partition/scandisk/defrag). All things considered tranfer rate is at best a optimal spec.

<font color=purple><b>Listen twice as much as you Speak. Better yet, Think twice. :wink: </font color=purple></b>
August 31, 2002 5:05:50 PM

well firstly..
the scsi drive that i bought was a apple mac model, so i had to use the 50 pin cable, so its not really as good as it could have been anyway..
as for the drive, a friend has it and i should have it back by tomorrow.
with the discwizard, nothing worked on it because the low level format i did wiped out the master boot record..
i dont think that there are any adaptors that fit a 68pin mac connection and then convert it over to a pc model.. apprently..
also the card is a direct clone from one of the more expensive scsi cards that adaptec do.. it was a copy of the 29xxx model or something..
im pretty sure that it will work when i get it back, the only problem is, what do i do, do i keep the drive and try and find an adaptor to convert from mac to pc or do i just get another drive altogether?
please advise!!

if all else fails... kick it and if it goes wrong, say it wasnt you...
August 31, 2002 7:49:52 PM

Oh, wait a minute I just noticed that your HDD is an Ultra2 wide LVD, so you can use the the Ultra2/Ultra160 cable. Best to stick with the Ultra160 LVD cable, because it can be used with either.

You said that the HDD model you have is <A HREF="http://www.seagate.com/support/disc/specs/scsi/st118202..." target="_new">ST118202<b>LC</b></A>, so it doesn't matter if it came out of a Mac, the SCSI connector for that model <font color=red><b>LC</b></font color=red> is 80 pin SCA, and the <font color=blue><b>LW</b></font color=blue> model is 68 pin. So the adapter I posted above should work, but here is another choice <A HREF="http://store.yahoo.com/directron/cables---adapters-scsi..." target="_new">Cables & Adapters</A> (sorry no picture for the adapter). I suggest you keep the HDD. You can replace/repair MBR with the DiskWizard 2002 and get your HDD back in working order. As for the controller, I've never seen that type and can't say good/bad about it. If the controller gives you the desired throughput you you expect...then keep it, but I perfer Adaptec or Tekram. I think your problem has a reasonable solution, so don't loose heart. You learn more with problems like this and with experience there is no price tag.

<font color=purple><b>Listen twice as much as you Speak. Better yet, Think twice. :wink: </font color=purple></b>
September 1, 2002 7:18:25 AM

Quote:
Ok, to clarify the 80 Mb/sec tranfer rate; means that the HDD is capabale of 80 Mb/sec under the conditions that the HDD is configured with compatible interface hardware

I keep telling you the bast that hard drive will do is a sustained transfer rate of 25,000. Please stop saying it will do 80,000 it can't, it won't, it just not possbile.

Quote:
but I perfer Adaptec or Tekram.

Ughh! Neither are very well thought off in high end SCSI. Mylex or LSI would each be better choices.

It's not what they tell you, its what they don't tell you!<P ID="edit"><FONT SIZE=-1><EM>Edited by ncogneto on 09/01/02 03:22 AM.</EM></FONT></P>
September 1, 2002 9:47:13 AM

hi again!
i think that the site that you posted in reply to, was the best bet, i have since been there and emailed the custome service desk about it just to make sure of what it is and whether or not it would be the one i would be looking for.
a friend is re-doing the mbr for me, so the drive should be back up and running today! i have my hopes as the drive is meant to be very fast (80mb/sec) and i would really like to see this as i havent used scsi before!! but i know now not to low level format the drive!! in diskwizard, how would i have repaired the mbr? i didnt see an option to do that.. sorry, maybe im just blind and stupid!!
well i was told that the card i have is a clone of one of the adaptec card, i think it was the 29160 or something.. apparently the money i paid for both the drive and the card, the card was worth the £70 i paid alone!! so i feel i really did get a good deal..
you said about the ultra 2 /ultra 160 cable, but does it matter about the drive being a non standard connection? the card i have got can use 50 pin or 68 pin connections, but i dont think over in england there are any converters from a 80 to a 68. im using the 50 pin connection and that was rather painfully slow... dont really want to go there if i can help it.
if i was to sell both card and drive and get replacements (as and when i might need to) what drive/adaptor would you recommend? i believe that the seagate drives are meant to be the best when it comes to scsi and the adaptec cards are meant to be the best, but they carry a very heavy price tag. i read that the tekram was as good a card, but just costed less.. any thoughts?
i thank you from the bottom of my heart for all the help i have had, i think its great when someone you dont know can be this good to someone, once again, thank you!

if all else fails... kick it and if it goes wrong, say it wasnt you...
September 1, 2002 6:11:16 PM

Ok, I did some reading and you are correct in regard to a single disk moving data. The real data rate would be approx. 15-25 Mb/sec for a single disk, but the maximum transfer rate of the host adapter's capability of moving bytes across the SCSI bus is characterized by it's own interface specifications (20, 40, 80, 160, 320). However, RAID 5 offers a better performance utilization of the data transfer rate as characterized by it's host adapter interface. Thanks for the correction, I'm never too bigheaded to learn.

Quote:
Ughh! Neither are very well thought off in high end SCSI. Mylex or LSI would each be better choices.

If you Mylex/LSI is your choice and it suits your wallet, go for it. But I was stating only my personal preference Adaptec/Tekram, because it suits my wallet.


<font color=purple><b>Listen twice as much as you Speak. Better yet, Think twice. :wink: </font color=purple></b>
September 1, 2002 7:32:07 PM

No, my friend you are not blind/stupid I checked out the contents of Seagats DiscWizard 2002 and it didn't list that capability. I have a different version of the Seagate DiscWizard on CD that came with one of my drives. It includes other special utilities, such as, "Drive Installation Software" So, I have that capability of replacing/restoring a MBR with this CD.

You are absolutely correct, SCSI is not cheap. So, what I was mentioning about the cables is that the Ultra160 LVD is backwards compatable, and the Ultra2 LVD cable can only work properly with an Ultra2 LVD drives <A HREF="http://adaptec-tic.adaptec.com/cgi-bin/adaptec_tic.cfg/...*&p_li=" target="_new">Compatibility</A>.

So, if you wish to save a pound with no intent of upgrading to a Ultra160 drive, go with the Ultra2 cable.

The reason I am referencing the 68 pin LVD (wide SCSI) cables is that you will be able to get better performance instead of using the 50 pin (narrow SCSI) connector on your SCA adapter. (You did say the adapter had both 50 pin & 68 pin connector...right?) If so, 68 pin is your best bet.

In reading your post you keep saying that your HDD adapter is not a 80 pin SCA - 68/50 pin converter. If then you did state that the HDD model was a ST118202LC, then it is an 80 pin SCA <A HREF="http://www.seagate.com/support/kb/disc/howto/interpret_..." target="_new">"LC Low Voltage Differential, 80-pin SCA"</A>,and if the adapter converter you have has bot 50 & 68 pin connecter, then you have all you need except for the 68 pin LVD cable. <A HREF="http://www.scsimasters.com/cguide.html" target="_new">SCSI Connector Guide</A>

Also, if the cloned SCSI Controller has a 68 pin LVD jack connector on it, then you will not need to replace it at all. Just connect your HDD to the 68 pin LVD connection on the card. When you get you drive back I hope all goes well.

Refer to the <A HREF="http://www.pcguide.com/ref/hdd/if/scsi/cablesTerminatio..." target="_new">PC Guide</A> to read about termination of the SCSI bus.

Regards

<font color=purple><b>Listen twice as much as you Speak. Better yet, Think twice. :wink: </font color=purple></b>
September 2, 2002 4:00:20 AM

Quote:
Just connect your HDD to the 68 pin LVD connection on the card. When you get you drive back I hope all goes well.

Don't forget the tremination.

It's not what they tell you, its what they don't tell you!
September 2, 2002 4:02:45 AM

The version of the software you need is seatools enterprise. This is a windows based aplication for SCSI and FC-al devices. From here you can format your drive.

It's not what they tell you, its what they don't tell you!
September 2, 2002 9:45:37 AM

Phill, alot of good advice has been given and I would hesitate to add much more. I would suggest very strongly to get some air moving over that drive, heat will kill SCSI drives very quickly. Either rig up an old case fan or get a good hard drive bay cooler kit made for SCSI drives, the fans do not need to be high air flow either.
For many months I had a low CFM 8cm case fan suspended behind my SCSI drive bay which made a huge difference to thier temperatures, my IBM 10k were at 35-40C which is 10C below the max' stated in the specifications.

<A HREF="http://www.btvillarin.com/phpBB/index.php" target="_new">A better place to be</A> :wink:
September 2, 2002 11:02:55 PM

When u use the 50 pin connector, u are working in 8 bits mode (between HDD and CTRLR), if u move to 68 pin cable u will go to 16 bits mode thus gaining non negligeable performances (check setup of the controler to put the speed u want). If u have only this HDD on the scsi CTRLR i think it could work without termination, But termination is recommanded, i think u can activate the termination via a jumper on the disk (go to seagate's web site to find info about your hdd's jumper).
Is there 1 connector only at the rear of the HDD or 2 separate connectors (1 power and 1 data)?
For what i read in your comments, i think u already have an adapter card at the back of the hdd...can u check pls !


What make us live is HOPE, never let it flee
September 26, 2002 9:53:05 AM

parts:
it was an 18.2gig seagate cheetah ST118202LW (link : http://www.seagate.com/support/disc/specs/scsi/st118202...) the card was an adansys ABP-940/70UW68, which im told will handle 40mbs/sec.. not bad i didnt think!!

i have recently purchased (through a lot of finding) adaptors for all drives and cables too (80 pin SCA to 68pin connections, £10 each, normally about £20 + i got 4...) .. got a bargin as well as i had a u160 cable with 7 devices on it for £23 each (i bought two :)  ).. it sounded good..
i have also bought 3 more (actually 4, they sent a freebie.. £30 for 4 drives, good value? they are seagate ST19171WC, 7200 rpm (sadly) ultra wide 2 (i think) drives since the one i had low level formatted (i still havent had that back yet..)..
as for getting back the drive i low level formatted, where would i find the tools to do the job? its a beast of a drive and i would really like to get it working..
was thinking of using the other drives in the k6 2 450 i have and possibly getting another adaptor card for the intel 3 533 i have.. its dead slow.. although the intel seems a lot slower with 64mbs of ram (i know its low.. needs more!!) compared to the K6 2 450 with only 32mbs of ram.. but thats a different story..
so could you please let me know where i could download/buy this software from? id really like to get the drive up and working..
i look forward to a reply, thanks to everyone that has helped me out here.. its really appreaited

if all else fails... kick it and if it goes wrong, say it wasnt you...
!