Onboard Scsi Controllers

[ClayMeow]

As you may know, I'm building a dual-opteron webserver. We want to have scsi drives, and looking around at mobos, I've found some that have scsi controllers onboard, and some that don't. I've also found single channel and dual channel ultra320 scsi.

http://www.tyan.com/support/html/scsi_dual_single.html

from what I can gather. If I were to have 2 scsi drives on a single-channel controller, then I would have reduced transfer speeds, but if I had dual-channel and had one on each channel, then I'd have the "full" speed available. We're most likely going to have a mirrored array, so dual-channel would be best.

 

My question is, is it better to go with separate scsi controllers, or are the onboard ones fine? (I'm looking at some Tyans, maybe gigabyte or supermicro if they're any good). Is it going to be drawing some processor power? Not a big deal with dual-opts, but hey, y not squeak out as much performance as possible, right?

 

Not sure if I'll go with 10k or 15k drives. I'm guessing 10k since 15k's are significantly more money, but price isn't that much of a concern. I'll have to present options to my boss, but he doesn't know much about computers, so I can easily point him in whatever direction I want. lol.

 

and answer my previous question as well, while you're at it:

http://forums.overclockersclub.com/Fsb_Or_...zel-t61352.html

nobody seems to ever like my questions. lol. where's bigred? is he the only one with experience with servers? heh

 

Thanks!

[bigred]

there are two schools of thought on this one.

 

1st up is the onboard is cost saving and saves a PCI slot. Okay I can agree with that.

 

2nd one is also a cost saving issue, but down the road. IF the controller fails you're out a mobo with the onboard. now you say "I'll disable the onboard and throw one in". well 1 of 2 things might happen there. 1 the raid array might not like that and so much for mirroring... or 2 the onboard scsi might conflict with the card. both of these things can be very bad in a server (been here had this headache before). this is why I personally suggest getting an addon card.

 

 

Just remember these words when dealing with SCSI in severs ADAPTEC is your friend.

 

 

oh and to answer your other question about the 90nm troy core vs sledgehammer... troy is cheaper due to the suply and demand on them. they're currently the chip still in production, the sledgehammer is out of production but is still in HIGH demand. why? since many opteron motherboard FAIL to support the 90nm chips that leaves the 250 sledgehammer as the highest end chip they can use. thus places are charging what they can get for them (wouldn't you?). cooling wise the stock retail opteron fans are the 100% identical to the stock ones you're used to seeing with retail athlon 64's and semprons... no different. they work FINE stock too. sledgehammers don't get that warm overall. at least none of the ones I've got (which most of my opterons ARE) run relatively cool.

Edited December 7, 2005 by bigred

[ClayMeow]

cool, thanks bigred! I knew you'd be the one with the answers . Quick question though. I don't have time to look right now, so excuse my ignorance, but if i go with an add-on card, instead of onboard, do they make dual-channel ones? and am i right in assuming that's preferrable? We don't need much space, so I'll probably get 2 36gb 15k scsi's, and I figure I'd put one on each channel, and have the "second" one mirror the first one.

 

and I'll definitely look into adaptec. thanks

[bigred]

adaptec makes had em in quad channel for a while. plus they make most of the onboard controllers on the better boards (ie dual channel).

[BabyBalrog]

As far as I know Clay, SCSI can satuarate a drive regardless of the channel. Sounds weird.

 

say a channel is Ultra 300 k? it runs at 300 MB/s ( this will depend of course on what controlelr you get) Now say each of yrou drives can stream at 100 MB/s so if you hook both to one channel you are getting 200/300 MB'/s so you're fine, IN old Slave/Master ATA setups you would only get one drive at a time so it would still be 100 MB not 200, not so with SCSI, (I'm 90% sure) BUT IF you get a dual channel controller go ahead and put then on seperate controllers, jsut incase

 

other things

What type of server is this going to be? If it's a small file size handler, looking into onboard cache's could give you good performance. But that's not for streamers, or non-high hit ratio setups.

 

Check out storage review to pick out good drives. I thinkthe 15k Atlas V tops the charts. Storagereview.com

[ClayMeow]

As far as I know Clay, SCSI can satuarate a drive regardless of the channel. Sounds weird.

 

say a channel is Ultra 300 k? it runs at 300 MB/s ( this will depend of course on what controlelr you get) Now say each of yrou drives can stream at 100 MB/s so if you hook both to one channel you are getting 200/300 MB'/s so you're fine, IN old Slave/Master ATA setups you would only get one drive at a time so it would still be 100 MB not 200, not so with SCSI, (I'm 90% sure) BUT IF you get a dual channel controller go ahead and put then on seperate controllers, jsut incase

 

other things

What type of server is this going to be? If it's a small file size handler, looking into onboard cache's could give you good performance. But that's not for streamers, or non-high hit ratio setups.

 

Check  out storage review to pick out good drives. I thinkthe 15k Atlas V tops the charts. Storagereview.com

604663[/snapback]

It's for our webserver that runs an e-commerce site via ColdFusion MX. All the parts were purchased last week (1/4 of them surprisingly delivered before the holiday weekend), so once I get them all, I'll be building it immediately. I will make a post with all the parts when I get a chance. Last time I was in the middle of it, I accidentally closed it before posting or saving it :angry2: