View Full Version : Serial ATA

09-04-2003, 03:52 PM
Just built a new computer for a friend and it has Serial ATA controller on the mother board and WOW I am impressed
I connected 2 new 120gig 7200rpm serial ATA dirves and striped them together and WOW the newtek DISK TEST tool gave me a reading of 117megs per second.
That is pretty impressive is anyone using these new drives with the VT3 yet


09-05-2003, 05:43 PM
FYI. Includes notes on SATA:


09-05-2003, 08:00 PM
Hey Don,

I just set up VT3 on a brand new system and it has on-board Sata connectors. Right now I have 2 WD 160s (8MB) buffer stripped as my video drives and they purr nicely. Mind you these are being run off one of the Promise TX 100 cards that came with the drives.

I was just curious as to what brand the drive were that you put in the system (the SATA drives that is).

I'm still learning about all this SATA stuff.


09-06-2003, 03:36 AM
Serial ATA is heating up!

The first generation of SATA is capable running at 150Mbps (Mega Bits). In real life, disks can operate constantly at 60% of their peak transfer rate, thus giving only 11MB (150/8*0.6 Mega Bytes) of data per second. This can only bring you 1 stream of uncompressed video provided you stripped 2 SATA disks.

Data transfer rate would NOT be doubled by stripping 2 HDD.
(Only 50% more on transfer rate, I guess.)

My best bet is to try the 3ware Escalade 8506-8 controller.

09-06-2003, 05:25 AM
Originally posted by JesusLovesU
....thus giving only 11MB (150/8*0.6 Mega Bytes) of data per second. That doesn't seem to correspond with Don's test, though, does it...

09-06-2003, 11:05 AM
I think it is megabytes not bits. Many now seem to ignore the distinction between MB and Mb. For example the VT documentation is always talking Mb but means MB.


09-06-2003, 12:20 PM
ok here it goes
The drives that I hooked up to that machine are
2 Segate SATA120/720 ST312023/26AS

so that is 2 120 gig dirves and they are stiped together

When I run the newtek drive test on them they give me back a reading of 117 Mb/s

soon I hope to hook up 4 of them to see what I get


09-06-2003, 12:35 PM
Hey taiji,

That was a good post
I think JLY should go there and read the specs on Serial ATA

because in there it says that the max transfer rate of SATA is 150MB per sec that is how fast the bus can transfer the data

and if you hook up more dirves I do agree that you can not exceed that transfer rate but to me that is pretty dam fast

I have a IDE setup on my VT3 that is hooked up to a promise controller and not a fast Promise controller and with 4 80gig 7200 ata drives attached I am getting only about 79 MB/s but this is fast enought to do 2 and maybe 4 streams on the Ted time line and so yeah maybe it does take a few seconds after I make my edit to build it in the background I can wait a few seconds

Pete Draves
09-06-2003, 05:11 PM
with the 64 bit 8drive 3ware controller using 4 drive raids
normal ide 120 ata100
I am getting a speed of 115 mega bytes / sec
I started using this type of raid on the digisuite le
transfered to the Targa 3000 .
On the T3k I was getting 4 streams realtime
I think serial ata is good but yet no worth the price.
It will come down soon.


09-06-2003, 11:33 PM
I only spent $120.00 each on those drives and I am talking about 2 dirves at 117 Mb/s with a serial ata controller

09-07-2003, 06:27 AM
what controller

09-07-2003, 09:07 AM
It is built on the motherboard
but it is the promise controller

so if you buy the promise Serial Ata Controller card and put it in a 66mhz slot it would work just the same they sell a 2 port and a 4 port and they are around 50 to 80 bucks

09-07-2003, 12:40 PM

What's the motherboard you're refering to?

09-07-2003, 03:20 PM
try 4 drives yet ??
Hurry!!!! I need the data before I decide which way to go.:)

10-02-2003, 01:46 AM
SATA rocks - I'm able to sustain a 180mbs rate off raid 0.

10-02-2003, 07:49 AM

How many drives are you using to get this performance??
Are you software striping or using a hardware card??

I am sure there are plenty who would like to know...

10-02-2003, 08:06 AM
now I see Sata drives with 10,000 rpm (usually 7500)
and seek times of 5.5 (usually 9)
this puts it in the same speed and seeks as Scsi

Altho still limited to 150 MB/sec (can you say scsi 160?)
for like half the price of scsi.

So how do you get 180 off drives that are only built to go 150
at optimal performance in labratory conditions?


10-02-2003, 12:23 PM
the 150 is per-channel. For RAID you're running multiple channels.


10-02-2003, 03:15 PM
I realize that.
I run Ide raid now, but there is no way that I know of to add all the drives to get 1 MB flow rate.
Like my 4 drives that theroetically can get 100 MB/s each will never get a theroetical 400 MB/sec rate.

I have never gotten over 79 so that's only 20 megs per drive.
that means I would need to put 5 drives in to get my 100 meg flow given 20 megs per drive.

Even scsi, running 7 drives on 1 channel at scsi 160, should by that example give me 1.120 Gigs/sec.
even a 50% return flow is 600MB/sec.
10% gives 112 MB/Sec

So given the 20% efficiency of my drives (which seems to be the average of Ide drives from posts seen here), is this tew best effiency that hard drives have?(well Ide anyways).


given 20 % rate of effiency that means he is using 6 drives at 30 MB/sec rate each.

Ok figured it out....nevermind