RAID on all 4 channels?

IvanLofgren

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I'm looking for a raid-motherbord that can raid all 4 ide-channels. Do they even exsist?

Specs: ATA/133, RAID 4 channels, pref. AMD XP ok.
 
There's Abit's AT7 or IT7 (AMD or Intel). They have 4 x ATA/33 & 4 x ATA 66/100 RAID.

Not sure if they're good though. Check for reviews.

<b><font color=blue>~ What do you mean "It isn't working!"...Now where's my sonic screwdriver? ~ </font color=blue></b>
 

poorboy

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Don't do it, Unless you only use 1 HDD per channel. IDE RAID is notoriously bad using both Slave and Master on a single channel. If you need that many HDD RAIDed, maybe a Promise or Adaptec card, or even SCSI, is worth looking at?

<i>I used to have a girl, but then I got my CS degree...</i>
 
Notoriously bad in what way?

I'm running master/slave set-up. Have been for months. No probs, and good benchmark scores.

I do want to try master/master to see if there <b>is</b> any performance difference, but I'll wait until I change to W2K.

<b><font color=blue>~ What do you mean "It isn't working!"...Now where's my sonic screwdriver? ~ </font color=blue></b>
 
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What do you mean "don't do it" I am thinking about this scenario for myself: I have 4 maxtor D740X hard drives and two Promise Fastrak 100 IDE cards. I want 2 separate RAID-0 arrays and I cannot use WIN XP software raid becasue my onboard IDE channels have backup harddrives and cd-rw etc. Should I set up 2 arrays on one card, or one array on two cards? In terms of system resources and transfer rates and simultaneous accessing, what would be better? I just read you said not to use master/slave, I was thinking of going master/master, slave/slave? Can anybody help?
 

poorboy

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Ok, what I mean is that performance isn't as good when using Master/Slave configurations. SCSI can do it well because the drives can disconnect from the bus and let others do some work while they're seeking or whatever, but IDE can't (que flames fom ppl saying some new IDE drives have "limited" diconnect features), so a concurrent read from both drives is actually a case of read from one, wait till done, read from the other. I'm not saying Master/Slave on one channel doesn't work, just that it's not the best option. Check out the manufacturers sites: The High-End IDE RAID cards support 1 drive per channel, not 2 like the lower end ones.

For Pzero, Fastrak 100 LP/TX2 have 2 channels anyway, so if you have 2 cards, plug one drive into each port and go for it (run both as Master). 1 Array per card, with 2 cards should run pretty nicely.

<i>I used to have a girl, but then I got my CS degree...</i>
 
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Thanks poorboy. My only worry is oversaturating the pci bus. With two raid cards, a nic serving my lan, tv tuner and sound card, I could end up causing a bottleneck! One last question: If I did setup two arrays on the same Fastrak card, with 4 drives master/master, slave/slave, would they run optimally with large file transfers between the arrays?
 

poorboy

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I really don't think so, but I'm guessing now... Depends how smart the controller is (can it actually do a drive to drive transfer without going through main memory?) and if there's going to be any data processing going on or if it's really a pure file transfer. You'll still have the Slave/Master problem, as it's an IDE Controller channel thing, not just an Array thing. The question is, does the PCI limit get reached with it all running, and if so, is that worse than the IDE controller delay? I'd be surprised if it does saturate during normal running, but there's only one way to find out: Spend an hour or two testing it and see what happens (time large copies, with and without other stuff going on, for both configurations).

<i>I used to have a girl, but then I got my CS degree...</i>
 
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Well poorboy, what you said about the "does the PCI limit get reached with it all running, and if so, is that worse than the IDE controller delay?" that was my question all along. BUT it turns out its all fruitless, I just got off the phone with Promise tech support and they say you can't run two Fastrak cards in the same system anyway, because the bios's will conflict, not knowing which to load first. SO my only option is to put all 4 on the one card as master/master, slave/slave.
 

IvanLofgren

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Tada! :)

Another way to fint the fastest way would have been to run a benchmark-program, but you wount need that now...

In Toms Hardware/How-To's you can find a couple of benchmark results on raid. win2000 software raid how-to game me some new knowledge... Check it out.

Another quastion is: If the motherbord got 4 raided IDE channels and I raid 3 master disks on 3 channels and let the fourth channel serve as an systemdisk/CD-R. Would that work? I mean - can i stripe three channels and put the forth channel out of the entire raid thing?
 

poorboy

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So that's 1 channel with Boot disk and CD-R, and then software RAID-0 across the other 3 channels on the master disk. That should work fine. The reason I wrote it in that order is to keep BIOS happy booting "C:" drive, so maybe you want to put it on the first channel, then RAID the rest. As far as the BIOS knows, it's just got 4 regular disks attached. You boot up the system disk (C:) and then Windows loads and does its thing with the other 3 disks.


<i>I used to have a girl, but then I got my CS degree...</i>
 

poorboy

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That's a Wise Thing tm. I don't suppose it's possible to disable a/the card BIOS is it, and just run it as a regular IDE controller? Alternatively, (and I acknowledge what Promise tech support said) Pzero, you've got the parts, so what happens if you plug them in? It just seems strange to me that they wouldn't work...

<i>I used to have a girl, but then I got my CS degree...</i>
 

IvanLofgren

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Inte the howto's here at toms hardware you might find a benchmart that have tested several raid configurations where, offcource 4 drives on 4 channels is the fastest and 3 drives on three channels comes next.
To benchmark this you must offcource hace a 4 channel system. Is this possible with pci cards at all? Can you combine a raid- and a controller-card to achieve a 4 channel raid system?
 

poorboy

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Combining a RAID and a regular controller isn't going to work so well - You'd be mixing software and hardware raid together. It *might* work, but I wouldn't expect great results.

Better would be using regular controllers with software raid on all 4 disks, or setting the RAID BIOS so the card operates as a regular controller (if that's an option). Most RAID Mobos can be set to operate in either mode. Remember that for *Software* RAID all you really need are disk controller channels with disks plugged in. Doesn't matter too much if they're PCI cards or the onboard controller.

It would of course be easier if you used a true 4 channel PCI RAID card, such as those offered by Promise (LP100 TX4) or Adaptec (2400A).

<i>I used to have a girl, but then I got my CS degree...</i>
 

Kennyshin

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Hm. I have been considering ABIT IT7 with 4-channel HPT-374 RAID controller onboard. That makes 6-channel ATA-133.

Six master drive ATA-133 Maxtor 7200rpm drives would make some difference in software RAID0?

<b> Searching for the true, the beautiful, and the eternal </b>
 

poorboy

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Looks like a pretty cool board. Except how you gonna boot if all your drives are *software* raided? I guess you could run 4 of 'em on the hardware HPT controller, and 2 on the regular controller under software if you wanted, as long as you boot off the HPT array. But damn, how many drives do you guys need?

Here's a little review with a disk benchmark <A HREF="http://www.hardocp.com/article.html?art=MjkzLDU=" target="_new">http://www.hardocp.com/article.html?art=MjkzLDU=</A> Not as fast as I though it would be, but nice none the less.

<i>I used to have a girl, but then I got my CS degree...</i>
 

Kennyshin

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Hm...

Thank you. Not as fast as I have expected either. Maybe its 4-channel RAID0 configuration does not offer any serious advantage over 2-channel configuration.

<b> Searching for the true, the beautiful, and the eternal </b>
 

poorboy

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Yeah, I suspect the HPT controller is limiting throughput. Those Maxtor D740X drives are spec'd for over 20MB/s minimum sustained transfer. I've got 2 running mirrored on a promise chipped Gigabyte motherboard, and it looks like it pulls 40MB/s too. (I'll do a decent benchmark this weekend for those interested). Perhaps there is a benefit with using a PCI card running a different chip?

<i>I used to have a girl, but then I got my CS degree...</i>
 

poorboy

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FYI, I got an overall sustained 35MB/s read, and sustained writes were down to about 17MB/s using bonnie++ under RedHat Linux 7.2. Running 'hdparm -t /dev/sda' told me 40.0 MB/s. System is an Athlon XP 1600+, 512MB DDR, Gigabyte GA-7DXR+ running 2 Maxtor D740X 40GB (7200rpm, ATA133) in RAID 1, using the Promise supplied kernel driver.

That's about right for this system (maybe just slightly low, as the box was running normally at the time of test), but makes me think something is capping the 4 drive setup mentioned above.

<i>It's all the same with the lights off</i>