Thoughts on Serial ATA

[Butcher]

Better to save your cash and just run normal IDE IMO, IDE RAID is just a way for a few card makers to make a fast buck.

[Brad]

but if it's integrated into a board, no reason not to use it.

if I never get a board without raid on it, I'm going to get a 15k rpm 18gb hdd. Which may be happening very soon, the iwill and abit boards neither have raid

[Jason711]

any mATX boards with ultra160?

[Brad]

there are 1u boards with scsi, but no matx's

[Jason711]

im willing to bet those cost a bit much..

[warp_zero]

BUT if you need cheap capacity, and you have a raid card... WHY NOT?

[Leuf]

Can't the highpoint controller used for most onboard raid be used as a regular ide controller? So, it's really a question of is it worth using it for raid in a desktop?

Aren't we at the point where hdd capacity has surpassed what is needed by the average user? I know people always think that, but honestly how much more bloated can windows get? No matter how big the drive is we can still find ways to fill it, but if you have 100+ gigs of space are you really feeling pressed to upgrade? The smallest drive you can even buy now is 20 gigs, and excluding my machine that is more than the other 3 pcs here combined. The only reason I have more is for video work, otherwise my old 8.4 gig is fine spacewise. But I would upgrade it because it's slow by comparison to a new drive. My point being that faster, quieter, more reliable seem like the best selling points now (side note: this makes the new ibm drives all the more mind boggling). I would love to have a smallish 10k rpm drive for the system and a slower drive for general storage, without having to go the scsi route.

[Butcher]

I have an 18G IDE for bulk storage and an 18G SCSI for my 3 OSes and most of my programs. It works well and I don't feel short of space in particular.

[Cyph3r]

ok... We all know that scsi has lower seek times and a bunch of other things that make it a lot better that ide.
I'll grant u all that.

<Disclaimer>
I do not work for any hw companies.
Opinions are my own.
I like SCSI.
I'm not advocating any hardware specifically
sorry for the long post
</Disclaimer>

the one thing that IDE has it's the only cheap solution we have vs scsi. IDE Raid makes things a little better but has these down sides

- More CPU Util
- Doesn't help seek times

Down side to scsi raid (other than cost)

- Doesn't help seek times

ok... for general reference scsi has ~ half the seek time of ide. I'm not being exact and i didn't go try to find the fastest seek times for both tech. this is just avg times.


we have scsi which is relatively expensive, but has very fast seek times and when combined into an array hands down the fastest sustained xfer rates.

ide is cheap... has relatively slow seek times and does fairly well during sustained xfer esp in an array.

SCSI = Performace platforms
IDE = everything else

some price comparisons... I didn't go find the largest SCSI u160 drive cause that's a moot point as far as expense. I did go find a 120gb for ide only for a price comparison. everything else is based upon some ppls perception that u don't need that much space. so i found the lowest price for some of the better hardware out there. notice i didn't claim the best.

seagate 18.4gb 10k rpm $145 1mb cache
fujitsu 18.4gb 10k rpm $153 8mb cache

adaptec aha 19160 u160 $147
mylex accelraid a352-2-32nb u160 raid 32mb cache $598
adaptec ada-2100s u160 raid 32mb cache $393

$292 for 1 drive and 1 controller
$683 for 2 drives and 1 raid controller

wd 120gb 7200rpm $177
seagate cuda 20gb 7200rpm $60
wd 20gb 7200rpm $62

HighPoint RR100 $35
Tekram DC200 $27
Promise FT100Tx2 $69
Adaptec 1200A $85

$177 for 1 drive (generally all mobos have ata100) or
$60 for 1 drive (for those who don't need 120gb)
$147 for 2 drives and 1 raid controller


ok it's 2 drives for the smallest array u can have.
i took the price of the cheapest controller so that way u have at least some kind of intro price to raid.

as far as serial ata goes, it's hard to say one way or the other... It'd be pure speculation on my part. There is the point that u have to run at much higher frequencies to get the same amount of data over a serial connection as u get over parallel. however, it'd seem really foolish to try to bring in a new tech that'd be slower. It has been shown that serial can compete with parallel (i.e. rambus) when used creatively (i.e. the quad pumped bus or whatever they call the bus for the P4). The only thing that comes to my mind as being a problem would be the cable length. I'm not sure how well high frequencies are preserved over long distances but then again how high will the frequency be for serial ata? it still has to travel at most 18(?) inches.


Just some things to think about.

Cyph3r

P.S. sorry about the long post

[Leuf]

Pretty timely article over at hardware central

http://www.hardwarecentral.com/hardw...inions/4109/1/

[Kevin]

Originally posted by Butcher
Better to save your cash and just run normal IDE IMO, IDE RAID is just a way for a few card makers to make a fast buck.

I dunno... I had dual 75GXPs back when those were the shiznat, and my read/write performance was DEFINITELY hot.
-Kev

[Butcher]

Originally posted by Kevin

I dunno... I had dual 75GXPs back when those were the shiznat, and my read/write performance was DEFINITELY hot.
-Kev

Yeah for block transfers it kicks, good if you do a lot of file copying (if you do maybe you need to reorganise ), or for video editing etc. For general app use I doubt you saw a vast amount of difference.

[nuclear]

Scsi raid 5 has changed a little bit since the newest i960 pci controller and raid hashing cpu has accelerated. The disadvatange of raid 5 on the write was the hashing of the xor information for the raid 5 ecc algorithm. It should be faster than raid-3 in write since you are not limited to one disk performance as raid-3. We are currently running many db on raid-5 system and they work flawlessly running at over 10 to 50 megabytes per second (depending on the server hardware. The fastest being a compaq alphaserver gs160) Raid 5 is fast if you have a hardware processor to do the hashing. Most of the latest scsi raid card use the intel 960 cpu and some ata raid card (adaptec aaa-udma use a hardware cpu for hashing). Raid-3 is also slowly removed from the option of hardware raid controller. The latest from dell perc3 controller does not have the options to make raid-3. It is raid-0, raid-1 and raid-5.

As for serial ata. it is already replaced by serial ata2. It will support commang queuing just like scsi. It will also support hot swap. It will also support switches so you can cluster the 4 interface of the board (which are supposed to run at aroung 150megabytes per second at introduction) and connect more than 4 drives on it. It is becoming more scsi than it is ata.
Their was an image at comdex about a dell 2550 with a devellopement promise serial ata raid card connected to the hot swap bay on the 2550. Their was 4 drives running each on their channel. Their was also a demontration of serial ata switch.

As for ata raid. I am currently running 2 quantum fireball as. their is 1 advantage in file copy and the other one is lower load time for apps and games. Running the game server. it does make a difference in the load time for the next map or the next chapter of the game

[Brad]

my new promise sx6000 has the i960 and raid 5 support