Overcoming the bottleneck: HDD's

[Con]

Hi, im starting to get a bit of cash together now im w orking again! I was looking at my system and was thinking i should be speeding up my hard drive because its the slowest thing. I am thinking the only way to do this and keep the costs down is going to be an IDE RAID 0 striping array.

This is what i propose:

Some RAID card? (help)

2*80GB WD 7200RPM IDE disks w/ 8mb cache

Now, i know the problem with raid 0 in that its only really AID (no redundancy) so if a disk dies im screwed. How reliable are these arrays? how much can i get a decent sized IDE tape drive for? or should i stick to CDR for backups. And suggestions on a raid card?

Cheers

Conrad

[Daniel ~]

I've found Promise to be as reliable as the hard drives you use with it. BUT... Other than for bench marks, don't look to see a big increase in speed doing day to day things. Photoshop and it's ilk are said to get a boost, but for most things...well I use RAID O to string smaller drive together, which it does nicely.

You might consider a new MB with on board RAID, you'll probably be happier with your gear in the long run":O}

[mookydooky]

The price of a RAID card lately is almost the price of a motherboard with RAID built in...so I would take Daniel~'s suggestion and seriously consider a new motherboard. As for reliability, perhaps you may want RAID 1+0, redundancy and speed. Reliability issues are also more significant if you seriously overclock your PCI bus. Just something to consider. Personally, I would never go with IDE tape. Tape just takes waaaaaaayyyyy to loooonnnnngggg to back up a decent size drive nowadays.

[Áedán]

Originally posted by Con
This is what i propose:

Some RAID card? (help)

2*80GB WD 7200RPM IDE disks w/ 8mb cache

Now, i know the problem with raid 0 in that its only really AID (no redundancy) so if a disk dies im screwed. How reliable are these arrays? how much can i get a decent sized IDE tape drive for? or should i stick to CDR for backups. And suggestions on a raid card?

A RAID 0 array is as reliable as the drives. If you put two IBM 75GXPs in the array, you'd expect it to be pretty unreliable! Basically, you can divide the reliability by the number of drives. How quickly do you think one or both of the drives will fail?

In terms of decent sized tape drives, they're not cheap, and generally, they're not IDE. If you wanted a tape drive that could back up all 160Gb on a single tape, you'll be looking near the £2,000 mark. A 15Gb IDE tape drive will cost about the £250 mark, with the tapes around the £30-£50 mark. As capacity goes up, price goes up rapidly. At these prices, it's cheaper to buy more hard disks and run a RAID 10 array (two RAID0 arrays in a RAID1 config). Of course, if you don't have that much to backup, it's not a problem.

In terms of IDE RAID controllers, 3Ware seem to be the most highly rated. They're intelligent hardware RAID controllers, rather than dumb software driven RAID controllers (A la Highpoint and others). They come in a range of sizes, supporting from 2 drives up to 12 drives.

If you're not serious about RAID, then a highpoint controller will probably do. If you're serious about RAID, or really do need the performance, then ignore onboard controllers and look at fully hardware based ones.

AidanII

[Con]

Cheers for the help guys.

Aidan, i know a bit about expensive tape drives ;D our servers at work that i control have Seagate/Sony AIT drives cost like 1500 quid for 70gb compressed!

[Áedán]

Originally posted by Con
Aidan, i know a bit about expensive tape drives ;D our servers at work that i control have Seagate/Sony AIT drives cost like 1500 quid for 70gb compressed!

What's the Sony AIT format like? I've been stuck with Quantum for too long (DLT), as most people seem to use that.

AidanII

[Con]

Its very fast! the tapes are extremely expensive tho! we were using 30/70's, and then got some 40/90 (i think) tapes and it wouldnt run compressed so i had to flash the firmware which took ages, as the drives are manufactured by sony and seagate and i was being bounced from company to person to company on the phone! bah@support! got a job tho!

Con

[Daniel ~]

God I hated the "consumer level" Tape backup drives! Slow and, for me, not all that reliable. Norton Ghost forever!

You do get stuck with your last back-up point, but it's relatively cheap, comes with several different motherboards for free and the only time it's let me down is when I've Ghosted the problem to my back up.

[Con]

try ghosting a 160gb drive \o/

[Daniel ~]

You've got a point their Loop, I've yet to hit the 4 gig mark! LOL

[Con]

Loop? Are you going Loopy ?

[spazzkid]

i think ive seen a "hard disk" that composes of sticks of sdram that u stuck into a pci slot. cant find a link of it. and yeah, its damn fast. damn, wheres that link... now i kudnt sleep tonight

[Áedán]

You be thinking of Cenatek's RocketDrive DL there then. Starts at $399 with 512Mb of memory onboard, and can be expanded to 4Gb of SDRAM. Unfortunately, it only comes with 4 DIMM slots, so I hope you have plenty of large DIMMS lying around!

Unfortunately, because it's SDRAM, it requires power all the time. An external power adaptor is provided, that plugs into the back of the PCI card to provide power when the machine is turned off.

However, if you turn the power off, even for a second, all of the data on the card is lost. A UPS is a must for this sort of card.

AidanII

[spazzkid]

ey thanks aidan, thats what i was talking about. now that "drive" wud be FASTER than any raid0 config. that might be the new standard on this coming years for all we know

[Con]

Surely PCI is only 164MB/sec isnt it? Why bother, cheaper to get an ultra-wide scsi drive

[spazzkid]

ultra wide scsi controller + drive = still expensive

btw, the rocket drive looks something like this:
http://www.cenatek.com/images/rocketdriveShot.jpg

[SteveI]

Originally posted by Con
Surely PCI is only 164MB/sec isnt it? Why bother, cheaper to get an ultra-wide scsi drive

The true benefit would be that transfer speeds would be sustained. The fastest scsi drives in a mult stripe array still could not be able to sustain... burst yes, sustain no.

[Áedán]

Originally posted by SteveI
The true benefit would be that transfer speeds would be sustained. The fastest scsi drives in a mult stripe array still could not be able to sustain... burst yes, sustain no.

PCI runs at 133MByte/sec tops (assuming 32bit and 33Mhz). The fastest single SCSI drive I know of can manage a sustained transfer speed of over 70MByte/sec. Ultra320 SCSI runs at 320MByte/sec, and Ultra160 SCSI runs at 160MByte/sec. Both of these are in excess of PCI's bandwidth.

So, two fast SCSI drives will max out 32/33 PCI's bandwidth.

Hence, most Ultra160 and Ultra320 controllers run on 66MHz 64bit PCI. (528MByte/sec transfer rate)

AidanII

[SteveI]

Originally posted by ÁedánII


PCI runs at 133MByte/sec tops (assuming 32bit and 33Mhz). The fastest single SCSI drive I know of can manage a sustained transfer speed of over 70MByte/sec. Ultra320 SCSI runs at 320MByte/sec, and Ultra160 SCSI runs at 160MByte/sec. Both of these are in excess of PCI's bandwidth.

So, two fast SCSI drives will max out 32/33 PCI's bandwidth.

Hence, most Ultra160 and Ultra320 controllers run on 66MHz 64bit PCI. (528MByte/sec transfer rate)

AidanII

I stand corrected.
So in striped array.. 2 top of the line scsi's could match the performance. (I don't even want to know what that would cost.)

BTW, did you just change your name like 2 times in the last 2 minutes?

[Áedán]

Originally posted by SteveI

I stand corrected.
So in striped array.. 2 top of the line scsi's could match the performance. (I don't even want to know what that would cost.)

BTW, did you just change your name like 2 times in the last 2 minutes?

The cost? Horrible... Ok, about $492 for the two drives.

You are indeed correct. It was done just to confuse you. I felt that perhaps it was time I went back to my roots.

Áedán