Can an UW cotroller run an U2W HDD repost

[Jimmy]

Well somehow my topic got lost and allthough I kept posting It couldn't be found on the BB.Anyway I got that reply from Quantum concerning the performance loss which although wasn't very helpful:

Dear Sir,
The Bus width will obviously decrease from U2W ( 80 Mb/s ) to 40
Mb/s ( Uw) as the drive will be forced into working in an earlier SCSI
protoccol. The reduction in performnace will further be influenced by a
number of other factors including the applications running, the number of
devices on the bus and the quality of cabling.

Tell me something I don't know pal.

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-=Jimmy=-

[Marshmallowman]

yes a UW controller can run U2W harddrives.
BUT you can only run U2W or UW on the card not a mix of both types. so if you already have UW HDD's you will have disconnect them to connect the U2W.
Well thats what I was told by a networking dude, it something about the lower voltages used by the U2W drives.

[Jimmy]

What if I run an Ultra device like the Plextor 40x CD together with an U2W device?

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-=Jimmy=-

[Guyver]

Unlike IDE your HD will not be limited to the slowest device speed on the chain. Also, SCSI supports multiple devices communicating simultaneously, whereas IDE only allows 1 device at a time.

Also, most of the UW controllers have 2 connectors on them, 1 for UW devices and 1 for Narrow SE devices. This should allow you to split them to different cables, termination, etc..

Guyv

[kelin]

I have to disagree with Marshmello...I ran both my UW IBM Ultrastar and Quantum Atlas 10K SCSI-3(160M/s) at the SAME TIME on my Initio 9100UW Controller...the only thing that happens is that both devices run at UW Speed...Now, with my Adaptec 2940U2W card...with the double bus(NOT 2 CHANNELS) I can run my Atlas 10K at U2W and my IBM at UW...IF you have UW, you can run up to 15 devices of ANY MIX of UW and U2W and still end up with UW (40 megs/sec max transfer rate)speeds...you just won't get the U2W (80 Megs/sec) max speeds...I don't know why Marsh...says you can't run both UW and U2W at the same time...BUT YOU CAN!!!
I have!!!!
Kelin

[Chucky Cheese]

jimmy,

my seagate drives have a jumper to force them to negotiate at single ended bus speeds, a big eye opener for me was to fork over the bucks for my scsi cables, i used to make my own from locally supplied connectors. same goes for the terminators, i got them from granite digital...WOW
here is my stuff....

Platform Configuration:

Motherboard: AMI MegaRUM II, dual 600Mhz Pentium III processors (installed), each with a 32/512 Cache configuration. 512 Mb of PC100, 8ns memory. Symbios Logic 53C896 U2W SCSI controllers. Intel 443GX Xeon chipset.

SCSI I/O:

Channel 1(LVD/U2): 4 Seagate LVD Cheetah 18LP, ST39103LW Ultra2 Wide SCSI-3 hard Drives, each with 1024k cache.

Channel 2(SE): JAZ 2GB internal, Plex-Writer 8/20, Pioneer DVD-303s ultra-scsi DVD reader and 2 UltraPlex-Wide 17/40 speed CD-ROM drives.

USB: USB Zip Drive, SideWinder Dual Strike 3D game controller

Networking: The network adapter is a 3Com 3C509B-TX PCI adapter and a US Robotics Courier V.Everything 33.6/28.8/x2/V.90 internal ISA modem.

Video: Matrox G400 Max with Dual Head. The primary display is a Panasonic PanaSync E21, .25-dot pitch, 20" viewable; the secondary display is a Viewsonic flat panel display model VP150.

Multi-media: Creative Labs Sound Blaster Live PCI Bus Mastering sound card. Speaker system are the Cambridge Works FPS2000 Digital speaker system.






[This message has been edited by Chucky Cheese (edited 09 December 1999).]

[Chucky Cheese]

hey marshmellowman,

the LVD(low voltage DIFFERENTIAL) designation by design means that the scsi bus uses the differences in the voltage states on any given pair of wires within the bus(i.e. 1 0 vs 0 1), the data is clocked both ways during the transition. all this is handled by the controller and is backward compatible with other scsi protocols...tell that to the networking dude.

my system specs are posted above...
U2W scsi RULZ





[This message has been edited by Chucky Cheese (edited 09 December 1999).]

[Jimmy]

Pretty impressive system config Chucky.Did U have to sell your house to buy it or what?Anyway noone answered my initial question:What will the peformance loss of running an U2W device on UW operation assuming that the 40MB/S limit isn't exceeded.
Kelin U have run the Atlas 10k on both the UW and the U2W bus.Was there any noticable performance improvement in the second case?


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-=Jimmy=-

[Chucky Cheese]

jimmy,

i built this thing myself, my friends estimate the cost to be between 8 - 10K, that includes both monitors, the hp officejet, the external print server, the hub and the 1400 VA UPS...TOYS TOYS TOYS, i think it might be a little higher. but hey, i happen to have a good job and NO kids! thats the difference for me.

anyways granite digital made my scsi cables and terminators. the terminators have lights on them to indicate what bus speed the bus is terminated at. i don't know if i buy it but the sales person/techie said that their terminators could store unique information from each scsi device it sensed on the bus, like TRMPWR.

chucky

[kelin]

Actually, the only real difference I have found was average throughput running at around 23 M/s when the Atlas 10K is on the Initio UW vs 26 M/s when its on the Adaptec 2940U2W...If I run the 10K on the 2940U2W UW BUS...I still get around 25-26 megs/sec...so, no, using the same SCSI card (the 2940U2W) I don't really see that much difference whether I run on the UW or U2W bus...maybe 5% if you look at all the the tests...when I get the chance I will do am intensive test to try a get a most exact picture of how much difference in perf I get with doth busses...As far as I know, the advantage will only really show up when using a few devices...for instance...if I had 2 Atlas 10K 160M/s drives...obviously, at 26 meg/s times 2 , I would be exceeding the 40M/s limit for the UW bus...then I would expect to see a difference with the U2W...where the U2W bus would allow me to achieve the higher average of 26M/s times 2 (for 2 drives) which equals 52 M/s...I would not think that I would see any degradation in perf having 2 of the 10K drives on the same U2W bus...BUT, THEN AGAIN...I AM MAKING AN EDUCATED GUESS!!! I don't have 2 U2W drives...so I can't tell...I do know,that if I run both the UW (IBM Ultrastar) and U2W (Atlas 10K) together, I see pretty much the additive...that is, the max additive transport is equal to what each drive gets running by itself added together...it SHOULD only be a problem, when the limit of either 40 or 80M/s is approached...
Again...when I have some time(I have been setting up a network at my place...and been busy with that)I will do a more expansive test...and post some real numberz...
Kelin
Primary System(98)
K7 650 on Asus K7M
256 Megs HSDRAM PC133
Adaptec 2940U2W
IBM Ultrastar UW 4.5 Gig
Quantum Atlas 10K 160M/s (SCSI-3)
G400 Max
aureal Vortex 2 2500 SQ
3Com NIC in LAN with tbase10/100 Hub

Secondary System (NT, Linux and 98)
P3 450 on Soyo BA6 +III
128 Megs CAS-2 PC100
2 UDMA HDS (1-/33 and 1-/66)
TNT
2 V2s
Creative Ensonic
3 Com NIC in LAN

[Marshmallowman]

I stand corrected, Aparently I have been talking out of the wrong orifice.

Mind you I got a cheap UW 9G seagate barra, because the seller said it was incompatible with his U2W drive. Have put off buying U2w, might have to reconsider.

Chucky , do you have a RAID setup happening, It can be done in software in NT 4.0.
(U2W has enough band width to feed those drives, even configured as RAID)

[Chucky Cheese]

marshmellowman,

i do have the raid card for this board. i noted during win2k setup that it looked for this card. i plan on going to a raid 0 configuration after the final release of win2k. can't wait to see how autocad runs!

chucky

[Jimmy]

Thanx for going into the trouble kelin.
Anyway I initially thought of buying an Atlas IV 9.1GB.I know U think it's a pretty cheap drive but over here it's pretty expensive for a HDD and SCSI drives are rare in general.Now I'm considering to buy a Cheetah 9.1 from a guy on e-bay.We'll see how it will work out.

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-=Jimmy=-

[kelin]

Sounds good...
Have fun with it and good luck...
Kelin

[Jimmy]

I bought the Atlas IV today.That deal with ebay didn't work.Anyway I haven't had the change to try it out yet.Anyone have any ideas about a good low-cost UW controller.I was thinking about the INITIO INI-9100UW but the DAWI DC2976-UW SCSI 3 is more accesible.Is it any good?

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-=Jimmy=-