SAS Drive in home PC

[topgun23]

Hi all, Just wondered how you would go about putting 2 SAS single port drives into a normal home PC?

Cheers

[TiG]

SAS isn't designed for a home PC, i'm assuming if you wanted to go down that line you could see if there where any SAS - 5 1/4 drive bay drive trays.

But SAS is designed for high density small u servers where you are trying to stick 6 drives in a 2U unit etc

You've got a good scsi card too i assume?.

TiG

[alsenior]

sas is too over the top for home pc's not to mention expensive.

the best bet would be an array of Western digital raptors on a 3ware or areca hardware controller

[arthurleung]

sas is too over the top for home pc's not to mention expensive.

the best bet would be an array of Western digital raptors on a 3ware or areca hardware controller

If you look at ebay, you can see insanely cheap Dell SAS cards and SAS drives

They're even cheaper than software SATA RAID cards.

I'm about to buy one of those cards for external RAID since I'm planning to move to shuttle.

[topgun23]

Lets say I have the drives - what would I need to intergrate into my system?
Cheers for the replys

[TiG]

A card that can connect SAS drives into it and if you are re-installing a machine with these as the main drives the windows drivers to control them.

Then obviously they won't stay in 3.5 or 5.25" drive bays unassisted so you'd want to have some way of securing them in your PC.

TiG

[Spammy]

Beware that many of the SAS cards don't come with cables, and these cables are anything but cheap (£40+).

I personally use a Dell PERC 5/i (which is just an LSI 8404 rebadged - you can even use LSI firmware) in my home servers. It absolutely flies!

Hope this helps,

Sam

[neils58]

Just the thread i'm looking for

I set up a new fileserver this week, with a perc5/i from ebay, and could use any tweaking tips that you could give. BTW, you can get the cables (SFF8484 to 4x SATA) sata cables @£10 each from a company called Span.

Using 4x500gb seagate 7200.10's, server 2003 x64, latest drivers i could find on dell's ftp site. I made sure to remove the jumpers so the disks are running in sata2 mode.

HDTach reports this, running in Raid5 mode:
[can't post screenshot until >5 forum posts]
Burst read - 427.4
average read - 109.5, and a flat line in the graph all the way along from 0-1.5TB
Random access - 13ms

Not too shabby, but nowhere close to what i was expecting from reviews around,including a hexus review of the lsi 8408e controller that the perc is based on, and 4 7200rpm disks in an almost identical setup.
I was expecting 160MB/s + sequential reads. Have tried anything i can think of, including trying a raid0 array with the same disks, and i'm still capped at just over a hundred MB/s (although my random access times were much better ~5.9ms).
Bursts seem to be fine though, which is confusing me. Playing around with stripe size, caching and read-ahead doesn't make a lot of difference, except to burst speed.

Please throw any ideas at me, i'll give it another couple of weeks before i give up and start moving my data on.

Thanks, Neil

[Clunk]

Just the thread i'm looking for

I set up a new fileserver this week, with a perc5/i from ebay, and could use any tweaking tips that you could give. BTW, you can get the cables (SFF8484 to 4x SATA) sata cables @£10 each from a company called Span.

Using 4x500gb seagate 7200.10's, server 2003 x64, latest drivers i could find on dell's ftp site. I made sure to remove the jumpers so the disks are running in sata2 mode.

HDTach reports this, running in Raid5 mode:
[can't post screenshot until >5 forum posts]
Burst read - 427.4
average read - 109.5, and a flat line in the graph all the way along from 0-1.5TB
Random access - 13ms

Not too shabby, but nowhere close to what i was expecting from reviews around,including a hexus review of the lsi 8408e controller that the perc is based on, and 4 7200rpm disks in an almost identical setup.
I was expecting 160MB/s + sequential reads. Have tried anything i can think of, including trying a raid0 array with the same disks, and i'm still capped at just over a hundred MB/s (although my random access times were much better ~5.9ms).
Bursts seem to be fine though, which is confusing me. Playing around with stripe size, caching and read-ahead doesn't make a lot of difference, except to burst speed.

Please throw any ideas at me, i'll give it another couple of weeks before i give up and start moving my data on.

Thanks, Neil

I also got my mini SAS cables from span. They have a bizarre amount of varieties of the same product, and I managed to pick up the cables I was after for about £7 each plus postage, and they were absolutely identical to the adaptec ones @ £23 each, and they arrived the next day by RMSD

[neils58]

Quick update - In the last few hours i put the 4 disks on the onboard nvidia raid (board is nforce 570 sli based) in a raid0 stripe, and was still only managing ~100MB/s. The drives all bench fine individually at around 70MB/s, so it might be a mobo/windows issue, unless the nvidia raid is crap and couldn't manage more than 100MB/s anyway.

[ikonia]

Home raid controllers are crap - full stop.

True SAS technology is aimed at the server market.

I'd be interested in where you picked up 500gig SAS disks as I thought the max available was around 350GB.

[neils58]

They arn't SAS disks, they are Sata Seagate Barracuda 7200.10 disks.

[madman045]

Just to give you an idea, the 1st one is a raid 1 array on a perc 5i controller in a dell poweredge 2900, the 2nd one is a second array on the same controller, raid 10

All the drives are 146gb 15k sas drives

[neils58]

Thanks Madman.

When i get home i'm going to try the drives outside of my sata backplane, on the remote chance that that is causing my bottleneck.

Once i reach 5 posts, i'll post my hdtach benches, my graph is a reasonably flat line, with no dropoff in speed along the graph.

[Clunk]

Sata RAID 5 FTW

[neils58]

Nice Clunk - is that 6 and 7 320gb 7200rpm drives there?

Removing the drives from the backplane seems to have made no difference, i'm going to try a 32bit OS tommorow. I put 32bit Ubuntu on there as a dual boot tonight and was getting 800MB/s bursts and 170mb reads from a 4 drive raid0 using hdparm - which, whilst better than my server 2003 x64 install, is still not where i'd expect to be on that setup.

I also 'modded' the raid controller, noticed the heatsink was getting very hot, so i attached a 40mm fan onto it.