Semmel

Atlas 15K on Adaptec 29160N -> 40MB/s !?

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I AM SCSI NOOB ! :D

I have got this: (it was very cheap)

- Maxtor Atlas15K 36GB U320 SCA 80 pin with adapter to 68pin

- Fujitsu MAN... 36GB U320 SCA 80 Pin with adapter to 68pin

- Adaptec 29160N with two 68pin cabels and two terminators

OK....

I tried more combinations of adapter/cable .... but I have never got more than 40 MB/s like!!!

Why?

Whats wrong?

Adapters = crap ??

SCSI Controller Settings = default

SCSI Boot-Screen:

Slot 2

Ch 1

ID 1

LUN 0

Vendor Maxtor

Product ATLAS15K_36SCA

Size 34GB

Sync 40 ---->> !!!!???

Bus 16

HELP PLEASE :(

atlas15k5zf.jpg

fujitsuman1pe.jpg

Edited by Semmel

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When the SCSI bios description appears on the boot up screen press ctrl + A and enter the configuration utility where you should then enter the scsi settings area and set the transfer rate to 320 with wide negotiation.

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In the bios I cant choose U320, only U160, but this is choosed!!

1 terminator is rated u160

the rest don't know....

but one cable is original from adaptec

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That leaves the 80-pin adapters then. Try to look for a picture on google resembling your adapters, and then look up the specs for that; might be SE only. And U160 in the BIOS is correct for a 29160N.

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The 29160N in is an ultra 160 adaptor, therefore no setting for 320 will be available. Further, I assume that you have the card plugged into a 32bit PCI 33MHz slot which will limit your data transfer to below the 132MBs theoretical limit. Since I don't know what else you have sharing the PCI bus in your computer, I have no idea if 40MBs is a good number or not, but it does seem a bit low.

Just don't expect to see anything near 160MBs.

Edited by ho

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Almost 100% sure it's the adapters. Most of them are crap. Get some decent ones from mcpricebreakers or scsi4me on ebay. Very affordable and guaranteed to link at U320 !

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The 29160N in is an ultra 160 adaptor, therefore no setting for 320 will be available. Further, I assume that you have the card plugged into a 32bit PCI 33MHz slot which will limit your data transfer to below the 132MBs theoretical limit. Since I don't know what else you have sharing the PCI bus in your computer, I have no idea if 40MBs is a good number or not, but it does seem a bit low.

It is damm low, around 110MB/s (Burstrate) are possible via the 32Bit PCI Bus, except you have a crap Chipset. ;)

Best regards,

Swen

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Sounds to me like he's in SE (Single-Ended) Mode. Check jumpers and SCSI bios settings.

I believe the N of the controller is for Narrow SCSI or 8 bit wide. This would reduce the speed to half of the speed possible, hence 80 MB/s.

The speed seen of 40 MB/s seems to be a hard set speed of ultra2 narrow (80MB/s /2 = 40) in LVD mode

It could be due to a speed negociation at power-up, not able to max out for some raisons already mentionned : cable or terminators (double make sure the drive does not have a jumper set somewhere...)

Good luck,

MEJV

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Sounds to me like he's in SE (Single-Ended) Mode. Check jumpers and SCSI bios settings.

I have 8 jumpers on the 80-68pin adapter:

LED

SYN

DLY

MTR

ID3

ID2

ID1

ID0

only ID0 jumper = enabled

@mejv:

I got this from adaptec homepage:

29160 = 64bit 66Mhz pci / 2-channel

29160LP = 64bit 66MHz pci / 1-channel

29160N = 32Bit 66MHz pci / 1-channel

@ho:

my pci bus is only used by SCSI!

100 MB/s burst and ~60mb/s seq. read should be possible

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Most definitely the SCA adapter, I have had the same problem with the older 1.5" high units but the newer 1" high units seem to do a good job even up to 320 !

Sometimes even the newer 1" high units have trouble with some drives so it is really pot luck unless the adapter is clearly marked for 160/320 operation.

Good luck.

Sounds to me like he's in SE (Single-Ended) Mode. Check jumpers and SCSI bios settings.

I have 8 jumpers on the 80-68pin adapter:

LED

SYN

DLY

MTR

ID3

ID2

ID1

ID0

only ID0 jumper = enabled

@mejv:

I got this from adaptec homepage:

29160 = 64bit 66Mhz pci / 2-channel

29160LP = 64bit 66MHz pci / 1-channel

29160N = 32Bit 66MHz pci / 1-channel

@ho:

my pci bus is only used by SCSI!

100 MB/s burst and ~60mb/s seq. read should be possible

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Start by removing one of the drives from the bus. This will reduce loading and let you know if you have a signal integrity problem. If that increases your bus speed then your next step is to get better adapters to improve the signal integrity.

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Most definitely the SCA adapter, I have had the same problem with the older 1.5" high units but the newer 1" high units seem to do a good job even up to 320 !

Sometimes even the newer 1" high units have trouble with some drives so it is really pot luck unless the adapter is clearly marked for 160/320 operation.

Good luck.

I have 2 drives and 2 different 1" adapters.

I tried all combinations, but I never get over 40 MB/s.

@hddmaster: I only have two drives and I have always run ONE drive.

Then I tried different ports, bios-settings etc., but nothwing helps.

On the host adapter, there are twi jumper:

LVD-TE

SE-TE

They are opened by default.

But I have closed the two jumpers separatly with no effect.

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I would try another scsi cable, i have the 27160 - the n is for 32bit pci, the 27160 supports up to 64bit pci. The flat cable that originally comes with the card is next to useless - i guess maybe if you install it one time it might be ok, but any changes and it seems to fall apart.

worse of all is that the terminator seems to be faulty - mine would sporatically fall to 40MBs sync and then next boot up it would sync at 160 (the default for atlas 18G).

It got so bad that ultimately it would not recognize the drive.

I replaced it with a LVD SCSI round cable and it fixed all the problems.

SCSI cables are unfortunatly not cheap, so it helps if you know anyone who has one that you can try or maybe if a local shop could try it for you. Anyways that was my experience with that setup (I actually had the Quantum atlas 18G (v2 i think) and then got it replaced with a Maxtor Altas 18G (v3 i think) when i RMA the drive because i thought the drive was faulty).

ANyways i hope this helps

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I would try another scsi cable, i have the 27160 - the n is for 32bit pci, the 27160 supports up to 64bit pci. The flat cable that originally comes with the card is next to useless - i guess maybe if you install it one time it might be ok, but any changes and it seems to fall apart.

worse of all is that the terminator seems to be faulty - mine would sporatically fall to 40MBs sync and then next boot up it would sync at 160 (the default for atlas 18G).

It got so bad that ultimately it would not recognize the drive.

I replaced it with a LVD SCSI round cable and it fixed all the problems.

SCSI cables are unfortunatly not cheap, so it helps if you know anyone who has one that you can try or maybe if a local shop could try it for you. Anyways that was my experience with that setup (I actually had the Quantum atlas 18G (v2 i think) and then got it replaced with a Maxtor Altas 18G (v3 i think) when i RMA the drive because i thought the drive was faulty).

ANyways i hope this helps

I agree. I use a 29160 and the original cable was uselss. i was fighting with the thing constantly booting at low speeds and i bought all new adapters 80>68 and it was still booting at wrong speeds frequently. Well i went and bought a U320 6 device cable and have NEVER had a problem since, all my adapters were fine even the first set and now i run 5 drives of the cable and controller. The cable LOOKED fine but i suggest you get a replacement and see if that fixes things, thats what ill bet my money on.

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