Quantum Atlas V + Adaptec 2940U2W Low Performance?

Hoping someone might be able to help me out here. I have a Quantum Atlas V 18GB SCSI drive on an Adaptec 2940U2W. Ive been fooling with benchmarks lately, and ive seen that my drive performs at about 25% of that of a similar IDE drive. Im not sure why that is... its my understanding that SCSI is supposed to perform at least the same, if not better. Anyway, ill post my specs just in case it is a conflict or something like that.
PIII 733 X2
ATI Rage Fury Card (being replaced soon by Radeon 64MB DDR)
D-Link 10/100 NIC
Sound Blaster 16 PCI
Adaptec 2940U2W SCSI Card
6x4x24 Ricoh CDRW SCSI
10X Pioneer DVD SCSI
18GB Quantum Atlas V SCSI
10 GB Quantum Fireball ATA66 (for storage)
hmmm, i think thats everything.

Any info or insights would be greatly appreciated.


18 answers Last reply
More about quantum atlas adaptec 2940u2w performance
  1. Please if you do find a solution to this problem let me know I have a really similar problem the HD is an IBM but I have the same SCSI card, I have tried a new set of cables another terminator I have taken any other SCSI device off the the chain but nothing... I get the same performance (according to Sandra SISOFT and other benchmarks) of a IDE drive
  2. I got the performance up to about 75% of an IDE drive by playing with the bios settings and removing my one IDE drive and disabling the IDE controllers. The BIOS setting that i change (and by BIOS i mean the SCSI card BIOS) that made the difference was the write back cache, which i switched from N/C to Yes ( or is that enabled?) Either way the write Cache is enabled from the BIOS. I assumed it was on because windows said it was, but i was wrong. I was thinking of upgrading the bios, but im not sure if i want to do that. Hopefully someone will see this and find something im doing wrong and fix it :-)
    Good luck and if i find anything out ill let you know.
  3. Can you post your bench marks? This is using PerformanceTest V3.4
    here mine
    Before I tweaked the SCSI Bios
    Disk - Sequential Read 5.1
    Disk - Sequential Write 3.1
    Disk - Random Seek + RW 2.9
    Disk Mark 29.3

    After SCSI Bios tweak
    Disk - Sequential Read 10.3
    Disk - Sequential Write 6.0
    Disk - Random Seek + RW 2.9
    Disk Mark 50.9
    So I can see some good improvements; however, benchmark with Sandra Sisoft my drive is by far the slowest compared to all
    the IDE drives
    Have you tried Sandra SISOF?
    My IBM Drive and Adaptec card were both OEM so I had to buy cable and terminator separately what about yours? I'm starting to suspect that either the terminator or the cable are not good quality ...... just don't have the $$$ to replace them....
  4. Before
    Sequential Read 8.3
    Sequential Write 4.9
    Random Seek +RW 31.
    Disk Mark 42.9

    Seq. Read 11.3
    Seq. Write 11.9
    Random Seek +RW 3.2
    Disk Mark 69.6

    I bought the card from a guy on ebay. Brand new retail box, with lvd cable included. Im redoing windows today as i have been having lockups and reboots, and beginning to suspect the card. Hopefully its just a software thing...
    good luck
  5. Please do post your benchmarks after you re do your PC
  6. Well, i moved my pci cards around so there is nothing sharing the scsi card, and the benchs are as follows:

    Sequential Read - 11.0
    Sequential Write - 13.5
    Random - 4.1
    DiskMark - 75.3

    Still Not sure why the performance is so low...
  7. Can u send me a link to the test you stated. I will post what i get with my IDE hard drive. I got a WD 15gb 7200rpm running at ata-66. Do you kno if the benchmark runs in win2k?? I got a dual boot between win2k and winME.

    Im savin up for a Cobra!! Hehe!!
  8. I bet that if you run the benchmark couple more times you will get lower scores like in my case, I just don't understand why the numbers are so low.....
  9. If i get a chance soon, im gonna test out my system with ann ATA100 IDE Quantum and see what happens.
  10. just to let you know I went out and borrowed a brand new cable and terminator that specifically said LVD run the benchmark again and got same results so it must be either the controller or the drive..... I also e-mailed IBM storage tech support asking about the poor performance they have yet to reply but I think it's going to take a while...
    I will keep you posted and if you come across anything else please share
    P.S. What Adaptec drivers are you running?
  11. Im running the standard drivers that come with win2k
    gonna try a few things soon, like updated drivers, and i still want to try an ATA100 drive and see the difference.
  12. I did run the benchmark on my other PC with a standard IDE drive and got better results than my SCSI !!! there must be something wrong with this picture..
  13. I just got an e-mail from IBM Tech Support asking about jumper settings on my drive... always wondered if I have somehow made some mistake when jumpering the drive, maybe you ought to look at your settings too
  14. hmmm, im pretty sure its right, but hey, its something i havent tried yet... and its been so long since i set it up, i cant remember exactly how i did it.

    Thanks, ill let you know how it turns out.
  15. no difference...
    i wonder if i got one of those counterfiet scsi cards...
  16. I don't think so.... I tried another Adaptec card (retail) and got the same results
  17. I'm not sure if you are even checking this post any longer but I thought I would share this with you, I purchased another IBM Scsi LVD drive (18 gig) ghosted the old hd into the new one the ran the test again and there is a huge difference I wish I had the result with me but I don't...
    good luck
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