The PC Gods have graced us with Serial ATA

[groth2757]

Who needs round IDE cables anymore? We got Serial ATA coming and I'm sure all of us can't wait to get our hands on boards that support this new interface. It seems the first hard drives will be out in a couple of months. OOooohhhh my hands are shaking, I NEED SERIAL ATA!!! What are your thoughts???

:tongue: <font color=red>Is it a bad if your memory module looks like a piece of fried bacon?.</font color=red> :tongue:

 

[camieabz]

What's the speed of serial ATA gonna be?

Characteristics?

Price?

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

 

[groth2757]

Well for starters the wire goes from an 80 wire 5cm ribbon to a 7 wire 8mm cord. The speeds are going to either remain the same or get even faster. Check out the link and look at the pics <A HREF="http://www.tomshardware.com/mainboard/02q3/020720/sis648-04.html" target="_new">http://www.tomshardware.com/mainboard/02q3/020720/sis648-04.html</A>.

:tongue: <font color=red>Is it a bad if your memory module looks like a piece of fried bacon?.</font color=red> :tongue:

 

[Crashman]

You really want to know my thoughts? Let's go through a history of this garbage:

Once upon a time there were two standards: SCSI and Winchester. The controller chip on the SCSI drives cost about $15 at the time I think, so cheaper computers came with "Winch" drives.

Later the IDE standard was developed to replace Winchester. AT the time, it still cost maybe $10 more to make SCSI drives. IDE interfaces started to be built into chipsets, reducing cost of IDE even further. Had SCSI been built into chipsets, it would have been a good deal for us all.

Now, the controller chip on SCSI drives cost around $3. SCSI has always been superior to IDE, offering connectivity for everything from drives to scanners, even cameras, but it never caught on because of those early price differences. The MAIN reason why new SCSI drives are still more expensive is because they are made in lower quantities.

So a few years ago, someone invented Fibre Channel. This is the idea that fostered Serial ATA. Fibre Channel was a subset of the SCSI specification, while Serial ATA was a new IDE standard. If SCSI would have been allowed by Dell to become a more common standard, we wouldn't need Serial ATA, USB, or Firewire, new SCSI standards wouldn have been developed to handle the connectivity of such devices.

So now we have 6 interfaces instead of one. IDE, Serial ATA, USB, Firewire, FDC, and SCSI. All of those COULD have been integrated into Fibre Channel. Imagine if your computer would have had only 1 data connection type instead of 5 or 6?

Serial ATA does adequately as an IDE replacement for Fibre Channel.

<font color=blue>At least half of all problems are caused by an insufficient power supply!</font color=blue>

 

[groth2757]

Is there any explaination as to why SCSI was kept down by the proverbial "MAN"? Was it because companies realized that they could make more money with more interfaces than just one? Or did they simply want to give people a choice? You made some very good points but do you think the Serial ATA will become the new standard and do you think it is a good choice? I for one love how much smaller the cords got....7 wires!!! That will really clean up the inside of your computer case dramatically.

:tongue: <font color=red>Is it a bad if your memory module looks like a piece of fried bacon?.</font color=red> :tongue:

 

[Crashman]

As I explained, initially it was much more expensive. By the time SCSI became a cost conscious option, IDE had already become "the" standard by being integrated into chipsets. At this point, companies could have switched back to SCSI without a significant price difference, but changing over would have resulted in short term cost. I am lamenting the loss of a superior standard.

Serial ATA could become the "one" standard, but never will because the other standards are so well established. It looks like a nice progress from parallel ATA anyway.

<font color=blue>At least half of all problems are caused by an insufficient power supply!</font color=blue>

 

[r2k]

The first hard disks and controllers will have maximum burst transfer rates of [up to] 150 MB/s (SerialATA/150 if you like).

But remembering that today's 7200rpm HDs (even the WD JB models with 8 MBs of cache) can't even transfer at 100 MB/s (hell, most of the time not enough to saturate even ATA/66) I think general users won't have ANY USE for the added bandwidth (remember ATA/133?). Although I'd say the space saving aspect is nice: I hate ribbon cables for cramping my case so much!

Anybody knows if SATA devices will have other performance increasing tune-ups to help them reach their theoritical speed? Also how big can the drives be? Does SATA use 48-bit or higher LBA addressing or is it completely different?

 

[Crashman]

Well, it could come in handy for RAID arrays, serial ATA can connect more drives per chain, no?

<font color=blue>At least half of all problems are caused by an insufficient power supply!</font color=blue>

 

[Vince604]

First off how does burst transfer rates really work? I mean IDE hardrives regular read/write speed is ~40MB/s down to ~20MB/s.. and then all of a sudden they can get 100MB/s?
So how much of a difference would it make with 150MB/s and 100MB/s? Can you actually see a big difference between the two?

I like the serial cable though if you were to have a RAID setup you'd probably have to wait for company's to integrate the serial ata interface..

But would anyone know when the serial ata drives come out if they would still have the regular ide interface for the regular 80 wire ribbon?

To my view I can't really see a huge jump from parallel to serial ata. Only advantage I can see is probably a much smaller wire, and hot-swappable. Other than for high-end raid servers I can't see where the rest of that extra bandwidth would go to for a regular home user... Like in the future it's suppose to be able to go up to 600MB/s burst transfer rates..

 

[r2k]

I think burst transfer rates are ones that occur between the hard disk INTERFACE and the chipset on the mainboard. Meaning if your device is capable, it can pass 33, 66, 100, 133, whatever MBs in one second. It's not the actual read perofrmance of the HD as in accessing and reading from the platter itself. I think large caches will help here very much.
I actually corrected myself by saying hard disks today cannot even reach the 66 MB/s burst transfer rate of ATA/66 (UDMA mode 4). Indeed a single HD in non-RAID0 configuration is normally doing between the numbers you mentioned. By increasing platter density (packing more data in a smaller area) and employing faster heads along with faster rotational speed, HDs are gradually moving up in performance. But I don't know when -without large caches- they can reach their theoritical maximum performance (as in peak transfer rates).

 

[sjonnie]

Yeah, that's what I had thought so I checked out the serial ATA specs at <A HREF="http://www.serialata.org" target="_new">www.serialata.org</A>. As I understood it with a serial connection you will only be able to attach one device per channel. The design specs of Serial ATA are intended to do away with Master/Slave jumper settings. This is why the new Shuttle Sis648 board had 4 IDE channels.

Having said that it looks as though Tom has it a bit confused. "In addition to a serial controller, the board offers four IDE interfaces for a total of eight devices." But if two of those are serial by my book that makes only 6.

 

[sjonnie]

SerialATA RAID cards have been available for some time now. <A HREF="http://www.highpoint-tech.com" target="_new">www.highpoint-tech.com</A> But still not a squeak about a serial ATA hardisc.

 

[PCcashCow]

Without repeating much that has already been repeated. The main issue will be price. Serial ata saddly will not be the 7th heaven weve all been looking for.

-Tim

It seems that every time I reboot my wallet gets smaller.

 

[sjonnie]

Serial ATA will not cost significantly more than the current ATA standard. This was set out in the white paper for its development. Hence Shuttle are able to offer it in addition to parallel ATA on their new MOBO.

 

[Crashman]

OMG! Simplified cabling? When you need ONE CABLE PER DEVICE? Four devices=four cables! You will need a Serial ATA router to add more drives to a single connector, and that means even more cables! SCSI makes ATA look horribly inadequate!

<font color=blue>At least half of all problems are caused by an insufficient power supply!</font color=blue>

 

[AMD_Man]

However, Crashman, Serial ATA cables are very thin unlike IDE or SCSI cables.

<b><i>"A penny saved is a penny earned!"</i></b>

 

[Crashman]

Ah, but they could at least put two connectors on each device so you could chaing them. In effect each device would have it's own router.

<font color=blue>At least half of all problems are caused by an insufficient power supply!</font color=blue>

 

[Hoolio]

The whole point of the one device per cable is so you dont need continuety devices or terminators.

Also someone mentions Firewire, this would have come about anyway, it is based around the ethernet standard but has less protocols.

Serial ATA will not be enough to get ahead of scsi or fibre channel.

I believe winchester was actually faster than scsi, that is why it was adopted but it had some huge limits.

I actually have a winchester drive somewhere with a controller, we found one in an old 286.

I found a good analogy on a website about ATA and SCSI:
------------------------------------------------------------
If you like non-technical analogies:

SCSI is like a palace, with an architecture that was well thought out from the beginning and built upon over a period of time to make it even greater than originally envisioned.

IDE/ATA is like a log cabin, with a dirt floor, built from whatever was found lying around in late fall just before the snow came. It can't be expanded because it has no foundation and would collapse under its own weight.

Both provide shelter. SCSI costs more (but not as much as a palace ).

Take your pick.
------------------------------------------------------------

I am going to go for SCSI320, fast better overall, also scsi can be used for scanner and more devices than just a HDD or CDROM.

IDE is specialise for DVD/HDD only. All the other interfaces you have mentioned support many different device types, you cannot compare them.

True drive heads cannot read the data fast enough to fill these transfer rates. I want the drives to go to static drives. I.E. No moving parts, microchips. These will be faster, why don't they work on these rather than producing faster interfaces, it should be 133MB/s sustained transfer.

 

[Crashman]

"One advantage of Serial ATA is that you don't need to configure Master/Slave jumpers". That's a euphemism for "The major disadvantage of Serial ATA is that it can only control one device per cable"!

<font color=blue>At least half of all problems are caused by an insufficient power supply!</font color=blue>

 

[lhgpoobaa]

urk... so its true then... i was hoping for at least 2 devices per cable. damn shame.

oh well. at least it solves (in a ugly way) the problem of multiple devices, device conflict, bandwidth sharing etc.

another question/query about the cables... from what ive seen they are longer (good) and thinner (good), but how flexible are they?
from the pics ive seen they dont look all that flexible. i.e. a bit stiff. will i be able to fold it up into a very tight bundle like i could with my mousecord? or is loops a few inches long the extent of its flexibility?

i hope they are cutable too! customise lengths to ones case

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[Vince604]

Ah I see. So your hardrive can actually get transfer rates of say 100MB/s for a regular IDE hardrive but only between the hardrive and the motherboard... Well right now motherboards only support a maximum of 133MB/s except for the Shuttle. But when I checked out the SIS 648 chipset there is no actual support for Serial ATA... So this would mean that the motherboard manufacture Shuttle added the Serial ATA interface feature?

Thanks sjonnie for the site. I don't think they specified what bandwidth the serial ata raid card can handle...

Would it actually be worth getting a serial ata hardrive now when it can only get up to 150MB/s or would it better just to wait when it gets up to 600MB/s?

 

[lhgpoobaa]

well i cant see any significant advantages performance wise of serial ata at the moment.

its bandwidth is starting at 150mb/sec... but one can have only one drive per cable, so the cable is hardly stretched for capacity given the best sustained transfer rates are around 50mb/sec.

maybe the interface itself will be optimised though...who knows.

probably wil have far better noise and error levels though

<b>Genius may have its limitations, but stupidity is not thus handicapped! </b>

 

[Vince604]

right. Just like ATA133 nothing really special when it became a standard for Maxtor.

Though even when the bandwidth does increase to say 600MB/s... How would anyone take advantage of that?

Right now I'm thinking about the WD1200JB as it can get transfer rates at almost 50MB/s which seems quite close to Serial ATA performance.. But for noise I'm not exactly sure but I think it'll improve a little but not significantly..

Wouldn't you think of Serial ATA right now at the moment as an little enhancement or small upgraded verison of paralell ide? I mean you can get rounded IDE cables and with a single WD1200JB drive you can get transfer rates pretty close to a Serial ata drive already.

 

[Hoolio]

Actually if the best any HDD can do is 50MB/s then they should adjust the controller to allows three devices per channel, therefore maximising the data channel.

Also why doesn't the motherboard standards allow a teriary onboard IDE controller. Maybe we will see the ability to have 6 HDD's on the serial ATA motherboards.

 

[lhgpoobaa]

3 devices per channel?
hmmm dont think that ata is set up for that...

besides, two fast 50mb/sec transfer drives is more than enough, given that even at the best of times you will never gain access to the full 100mb/sec (or 133mb/sec) due to overheads.

dont want excess competition on the cable do we?

as for tertairy controllers... well a different solution does exist with the abit KT-333 motherboard.
it has the standard primary and secondary IDE channels for 4 drives, and an onboard raid chip.
the onboard raid however has 4 channels, not the typical two! so between the 4 channel raid and the standard IDE channels you can attach up to 12 IDE devices!!!
not to mention any sub2 or firewire ones.

<b>Genius may have its limitations, but stupidity is not thus handicapped! </b>