scherer@dtrc.dt.navy.mil (Scherer) (05/05/90)
I have experienced a problem now over the last 6 months that I found
very interesting and wondered if anyone else has had.
I've purchase about 20 Seagate ST251-1 drives and found that they all
worked well but when I ran benchmarks on 3 of them they were really
ST251 (40ms) drives. The cases were marked as -1's though. When I
received the first drive that was marked wrong I called the vendor
and he thought I was crazy but I insisted he replace the drive. When
I received the new drive it seeked at 28ms. The vendor said Seagate
must have marked it wrong. Two days ago I bought 3 drives and ran
Checkit and Spinrite on 2 of the ST251-1's and they both benchmarked
at 48ms seek time. These drives were purchased from a different vendor
than the one I used when I had this problem originally.
What's going on with Seagate! It's one way for them to get rid of
ST251's left over.steve@wintermute.ucsd.edu ({Darkavich}) (05/07/90)
In article <1806@nems.dt.navy.mil> scherer@dtrc.dt.navy.mil (Doug Scherer) writes: > > I have experienced a problem now over the last 6 months that I found > very interesting and wondered if anyone else has had. > > I've purchase about 20 Seagate ST251-1 drives and found that they all > worked well but when I ran benchmarks on 3 of them they were really > ST251 (40ms) drives. The cases were marked as -1's though. > > What's going on with Seagate! It's one way for them to get rid of >ST251's left over. Well, there are two thing that you need to make sure that you have done. The first is to make sure you have a 1:1 interleave controller card in your computer. If you do then you need to make sure that the hard drive was low-level formated with an interleave of 1:1. If the former is not true then you need to buy a new controller card and re-low-level format the drive. (Make back-ups!!!!!). If the latter is true then all you need to do is use a program like Optune from Gazzelle software and it will re-format the drive with a inter-leave of 1:1 or tell you what the best interleave should be. (Eventhough it does it with out corrupting the data on the drive it is still a good idea to make back-ups) Know a question for those people out there that can help. BTW. I have a seagate 251 and a 1:1 interleave controller and the drive is partitioned 2 meg, 20 meg, and 20 meg. I formated it with a 3:1 interleave like seagate says. After running optune on it it still tells me 1:1 is best. I re-formated the C drive and it knows runs at (17ms) according to QAplus. I do not have benchmark so I cann't tell it that is the true ms time. Norton's (si) tells me 3.7 so it is right around 28ms or less. I keep forgetting my conversions. Anyway my question is using Optune, I try to re-tune the D and E drive but it tells me that I must turn off disk caching first! I have no disk cache, neither in memory or in set-up. I have an AT-12mhz with AMI BIOS. I have removed everything from memory except my disk manager software. The only thing I can think of is that I have a 0 wait state machine and maybe it uses cache to achive this and the software is seeing this assuming it is disk cache. Does anyone else know what may be wrong or experienced this problem?? Thanks, All help is greatly appreciated. Steve Misrack steve@ucsd.edu
scherer@dtrc.dt.navy.mil (Scherer) (05/08/90)
In article <13489@ucsd.Edu> steve@wintermute.ucsd.edu ({Darkavich}) writes: >In article <1806@nems.dt.navy.mil> scherer@dtrc.dt.navy.mil (Doug Scherer) writ >es: > >The first is to make sure you have a 1:1 interleave controller card in your >computer. If you do then you need to make sure that the hard drive was >low-level formated with an interleave of 1:1. If the former is not true >then you need to buy a new controller card and re-low-level format the Deleted Stuff Steve Misrack > steve@ucsd.edu I appreciate your response but your confusing seek time and data through put. Interleaving does not affect seek time. Seek time is how long it takes to get from cyl. A to cyl. B. All the bench mark tests I ran calculate this for you. Besides all that when I replaced the drive with another ST251-1 the seek time went to 28ms from 48 with the same controller installed.
chao@tornado.Berkeley.EDU (Chia-Chi Chao) (05/08/90)
In article <13489@ucsd.Edu> steve@wintermute.ucsd.edu ({Darkavich}) writes: >In article <1806@nems.dt.navy.mil> scherer@dtrc.dt.navy.mil (Doug Scherer) writes: >> I've purchase about 20 Seagate ST251-1 drives and found that they all >> worked well but when I ran benchmarks on 3 of them they were really >> ST251 (40ms) drives. The cases were marked as -1's though. > >The first is to make sure you have a 1:1 interleave controller card in your >computer. If you do then you need to make sure that the hard drive was >low-level formated with an interleave of 1:1. If I understand it correctly, the 28ms rating (251-1) is the average seek time -- how fast the drive can move the heads. It is the physical limitation of the drive and has nothing to do with the interleave factor, although both affect the throughput. Chia-Chi chao@ocf.berkeley.edu