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A little scsi help please

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September 25, 2006 2:12:15 AM

I know nothing about scsi so i am just starting to read about it. I got my hands 2 scsi 73gb 10k rpm seagate cheetahs they are 80pin (scsi 160?) but have an adpater to bring it to 68 pins.So my main questions is about the pci card i need (most likely will use the hdd with a asus p5wd2-e) now would it be worthwhile to raid the two hdds? I assume a raid scsi card is expensive but raid is not totally necessary does anyone have any ideas on what card to get, Is there something else i should lookk into? looking at the prices i might go used (ebay)

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September 25, 2006 3:23:02 AM

I think an 80 pin connector might be an SCA which is used for hot swap trays - here is some pictures:

http://www.scsita.org/aboutscsi/Pictures.html

You also mentioned an adapter, does it have a breakout for power? hot swap connectors have data & power so your adapter would need to address that.

As far as the PCI card goes, Adaptec is probably the most widely used brand.
September 25, 2006 4:33:15 AM

Quote:

You are going to need a PCIe U320 SCSI RAID card if you plan to RAID.
Most findable and cheapest so far is LSI MegaRAID SCSI 320-2E.
You're going to have to fork out at least $250 for one on eBay(brand new) otherwise it's over $500 retail.



Its going into my desktop and was planning to put the windows installl and games only on these drives.

Ok raid might be out of the question as its a bit pricey


Quote:
I think an 80 pin connector might be an SCA which is used for hot swap trays - here is some pictures:

http://www.scsita.org/aboutscsi/Pictures.html

You also mentioned an adapter, does it have a breakout for power? hot swap connectors have data & power so your adapter would need to address that.

As far as the PCI card goes, Adaptec is probably the most widely used brand.


yea they are like the one in the pic "New SCA 80-pin"

the adapter to 68 pin does have the molex connector.

this brings me to another question i just found 2 more 36gig ibm 10k rpm drives, that have 68 pin connectors , i asssume from your question that this 68 pins need a powerplug plugged in to work? (i know it sound like a stupid question)

Quote:
Quote:

Power connector is on every 80->68pin converter. Quite logically really and wouldn't exist without one.

Adaptec doesn't make any PCIe parallel SCSI cards.
LSI has been in the SCSI bussiness a lot longer than Adaptec and only makes hardware solution for enterprise. No kiddie playing host stuff.


So whats the difference from pcie and pci and parallel? I assume that pcie has better data throuput?


Thanks everyone for the help and speed responses , shedding some light on it for me.
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September 25, 2006 5:12:36 AM

Quote:
So whats the difference from pcie and pci and parallel? I assume that pcie has better data throuput?


Theoretically, yes, but it really isn't. THG actually just did a test on the benefits of PCIe vs. PCIx, and the difference is negligible. Don't bother spending extra.

Congrats on the SCSI drives, wish I was that lucky to just have them fall into my lap...but I'm quite content with my single Raptor :lol: 
September 25, 2006 5:26:37 AM

I wonder if anyone can give a real world impression of SATA vs SCSI in a server application. I have two web / db servers load balanced that take a pretty good load almost 24X7 and they are RAID 10 SATAs (Raptors) - I think they perform great, I don't have SCSI envy!

But, I read something recently that suggested that SCSI could perform multiple I/O's simultaneously and ATA can not - anyone care to comment?
September 25, 2006 6:01:50 AM

Quote:
So whats the difference from pcie and pci and parallel? I assume that pcie has better data throuput?


Theoretically, yes, but it really isn't. THG actually just did a test on the benefits of PCIe vs. PCIx, and the difference is negligible. Don't bother spending extra.

Congrats on the SCSI drives, wish I was that lucky to just have them fall into my lap...but I'm quite content with my single Raptor :lol: 

Well now I am getting all turned around i know pci , pci 1x, pci 4x , and pci express (video card slot). Pci express is the fastest correct? I was looking for a controller card for pci It looks to be more popular i actually have not looked for any thing else.

Quote:

You are going to need a PCIe U320 SCSI RAID card if you plan to RAID.
Most findable and cheapest so far is LSI MegaRAID SCSI 320-2E.


One external P68 connectors (VHDC)
One internal P68 connectors (UHD)

I have been looking at this card and can figure out how raid would be hooked up if you use the 68 pin connector. Can you daisy chain (serial) on the same connector?
September 25, 2006 12:56:24 PM

sure, you can. Just get yourself a U160 Raid card on ebay.. not a problem.
You will have good performance with a $100 ebay card. Trust me.
there will be a substantial advantage over SATA. MAinly depending on your apps. With my setup, i notice the speed, when i do a number of sequential read / writes. IE multiple file copies, or when i multitask, with a number of apps, that are disk i/o hungry. playing games, you will notice. especially if you stripe the.
September 25, 2006 5:34:18 PM

Jeez this is alot of info ....................But i am getting it
I think i will go for the raid card LSI MegaRAID SCSI 320-2E. it will take one video card slot but since i couldnt get sli to work and i dont have pci-x
{asus p5wd2-e
PCI Express x16 2
PCI Express x1 1
PCI Slots 3
Other Slots 1 x Universal PCI-E (max. x2 speed)}


but couple of more q's , I assume raid for scsi is the same as for sata the drives need to be same (storage /rpm wise)
I do have the scsi cable and does have the termination ( was wondering what that was) the cable has six 68 pin connectors do i have to use all the connectors or can i leave them empty?
Thank's
whats the difference between u160 and u320?

Oh all these drives where used i bought a surplus server only because i wanted a dual p3 setup (i just like em) was not planning to do anything with it besides look at it. I knew it had the 2x 73g scsi but when i was taking it apart found the 2x 36gig and 1x 18 scsi hiding under the dvd drive
September 25, 2006 6:19:06 PM

Just a side note: PCI is a garbage bus for Mass-storage. It's a synchronous bus, meaning that if another device on the PCI bus hangs, for ANY reason, no other device on the bus can communicate until the hanging device releases the bus.

Even if you don't have any cards on the PCI bus, a lot of Integrated Mobo devices use the PCI bus.

This means if your integrated sound controller or NIC uses the PCI bus and decides to start going, it has a great impact on your hard drive performance. Also, PCI bandwidth is shared among all devices on the bus. PCIe, by contrast, has dedicated bandwidth per-channel. it's also async, meaning one [misbehaving] device on the bus won't affect another device on the bus.

In-short, don't waste your money on a PCI SCSI controller. Let us all advocate the extinction of the PCI bus :) 
September 25, 2006 6:23:57 PM

u160 and u320 are logical names, data flow is doubled and the clock speed is tweaked.

Quote:

Ultra3 SCSI-3
SPI-3 16 16 bits 40 MHz 160 MBps
Ultra320 SCSI-3
SPI-4 16 16 bits 80 MHz 320 MBps

Raid on SCSI does work the same as conventional raid, arguably more powerful. Be sure your terminators can take higher voltage 320. Not all are the same and not all are backwards compatible.
You will need on connector for the terminator, then you'll be able to populate all the open "connectors".
However, it is not recommended that you put more that four drives on a single channel.
September 25, 2006 7:05:02 PM

Quote:
You will need on connector for the terminator, then you'll be able to populate all the open "connectors".
However, it is not recommended that you put more that four drives on a single channel.


little cofusing i have a terminator, ( or i think it was a terminator), it was already attached to the cable.(just looks like a pc bord nothing else on it)
What do you mean a "connector for the terminator" , the cable i have has 6 connectors i only have 2 hdds.
September 25, 2006 8:31:46 PM

Ok,

It sounds like the cable you have was part of an oem setup. If you can trace the origin of the cable or pull some numbers off the cable to see what type of termination the terminator is capable of. (it is confusing..at first, then its gravy!) On most home setups you get a cable with around 5 or 6 68pin connections on it. AT the very end of the cable is where the terminator goes, then you just plug, raid, and play. Sorry if I confused you! I'm still nursing a hangover, f'n Giants!
September 25, 2006 9:29:01 PM

With everything thats happening concerning SAS or with SCSI vs SATA, you have a greater throughput with SCSI because of bandwidth, BUT more and more Corp. are using SAS (SATA OVER SCSI) for cost savings for non-nessisarry data.
September 25, 2006 10:19:03 PM

Quote:
Quote:

You are going to need a PCIe U320 SCSI RAID card if you plan to RAID.
Most findable and cheapest so far is LSI MegaRAID SCSI 320-2E.
You're going to have to fork out at least $250 for one on eBay(brand new) otherwise it's over $500 retail.



Its going into my desktop and was planning to put the windows installl and games only on these drives.

Ok raid might be out of the question as its a bit pricey


Quote:
I think an 80 pin connector might be an SCA which is used for hot swap trays - here is some pictures:

http://www.scsita.org/aboutscsi/Pictures.html

You also mentioned an adapter, does it have a breakout for power? hot swap connectors have data & power so your adapter would need to address that.

As far as the PCI card goes, Adaptec is probably the most widely used brand.


yea they are like the one in the pic "New SCA 80-pin"

the adapter to 68 pin does have the molex connector.

this brings me to another question i just found 2 more 36gig ibm 10k rpm drives, that have 68 pin connectors , i asssume from your question that this 68 pins need a powerplug plugged in to work? (i know it sound like a stupid question)

Quote:

Power connector is on every 80->68pin converter. Quite logically really and wouldn't exist without one.

Adaptec doesn't make any PCIe parallel SCSI cards.
LSI has been in the SCSI bussiness a lot longer than Adaptec and only makes hardware solution for enterprise. No kiddie playing host stuff.


So whats the difference from pcie and pci and parallel? I assume that pcie has better data throuput?


Thanks everyone for the help and speed responses , shedding some light on it for me.

Don't count out Ebay... I bought a U160 LSI MegaRAID card with 32MB cache there for $25. Runs my dual 36GB 10K cheetahs pretty well (I added some cache- 128MB SDRAM DIMM), noisy though- you know those drives are enterprise class right? silence is not really a requirement when they design them. ESPECIALLY the 80pin SCA drives. The FDB does help though.

BTW, you don't really need U320 for two drives. Even at 10k, they'll max out around 150-160 MB/s which is pretty cliose to the limit of the controller. And PCI should be able to handle that.
September 26, 2006 5:06:09 AM

Yeah, if you have a dell server just lay'n round :) 

I've just aquired 4 15k 36GB Hitachi's. Not sure what I'm going to do with them. I love it when my company lets me upgrade, I get the old ones!

I can tell ya that scsi will spank sata's arse, I have one server at work with 8 wd 320's RAID edition in a RAID50 off a zero channel raid in a superserver (yeah I know it's not the fastest RAID controller) and it's slower than my dual RAID0s on 4 74GB 15k Hitachi's with another superservers integraded controller, no zero channel. Both running dual Dempsey 3Ghz's. SQL loves the scsi.

High end SAS will work as well as pure SCSI from what I've heard thou I have yet to play with any SAS stuff.

Memorize the different forms of scsi and the cables/terminations/pin counts, etc. Then SCSI will be second nature. I think I have a couple drives from every generation at this point, my 4 new ones fill the u320 gap, and my mac classic (among others) covers the original scsi :)  Gotta say for being 14-16 years old those 40mb drives still work great!

In response to wizzard9992, if you ONLY have a scsi card in a pci-x 133Mhz then you'll be fine as long as the server board doesn't have a gige nic running pci also :)  But that kinda limits expansion. PCI-e is certainly the future. My PCI-e 4x RR card has higher bandwidth being full duplex, and it's not a server board!

EDIT: Lots of gateway unlocked lsi's for $120, pci-x though,

Cheap LSI MegaRaid 320's
September 26, 2006 6:12:11 PM

that's why I wanted to do some kind of raid with it, I have a sata 8mb buffer in there now and all benchmarks for hdd testing are horrid. I am not expecting a scsi 10k rpm to compete with raptors but in a raid setup I hope it will help in benchmarks.
As far as real world performance my world consist of playing games and some DVD burning so I am not expecting much. and my pc boots to window fast enough for me so that's not a real issue.

I just went with scsi because I knew nothing about it and like to mess around learn first hand but I "bit off more that I can chew"

now do enthusiast boards come with pci x slots? or just server types and correct me if I am wrong but isn't Pcie newer then pcix ?
September 26, 2006 7:08:59 PM

Mostly serverboards, but there are a few single cpu mobos out there that lable themselves Performance desktops, which are quite expensive.
!