Ultra DMA 33/66/100

[Guest]

what is the difference between those three bus speed 33,66 and 100?my Asus p2b motherboard supports till 66 Mhz so what does it mean?

 

[Lars_Coleman]

What's 66MHz? Your Front Side Bus?

That mother board supports DMA 33 and a FSB of 100 or 66MHz.

The difference between the three are the burst transfer rate. For Example :::
DMA 33 = 33MB/sec
DMA 66 = 66MB/sec
ATA 100 = 100MB/sec
ATA 133 = 133MB/sec

<font color=red>1GHz AMD x MSI K7T-Turbo x 512MB PC133 x 2-Maxtor 30GB/RAID 0 = Stream Line Butterfly</font color=red>

 

[Crashman]

The fastest, UDMA 133, will give your system about a 5% boost over the slowest, UDMA 33. This is because most drives can't tranfer above 40MB/s anyway, except in burst from the drive's cache, which is very small for most IDE drives.

Back to you Tom...

 

[Arrow]

The difference between the ATA standards themselves is the <i>ability</i> of a device using that standard to transmit at that speed. Whether or not the internals of the device itself allows it to provide a sustained speed of a certain ATA standard is another matter.
ATA standards are backwards compatible - ie. you can use a higher standard motherboard with a lower standard HDD and vice versa.

Rob
Please visit <b><A HREF="http://www.ncix.com/canada/index.cfm?affiliateid=319048" target="_new">http://www.ncix.com/canada/index.cfm?affiliateid=319048</A></b>

 

[upec]

ATA 133 also allow hard drive with capacity over 137 Gig.

 

[Guest]

well today i experienced somethign weird..since the mobo and the HDD is backwards compatible..
here is the story. my fren bought a maxtor 40 gig 7200 rpm
and installed into his machine!it CANNOT be detected then we went to the shop again to change for maxtor 30 gig 7200 rpm and it CAn be detected..
anyway his pc spec is a K6-3 450 and his motherboard maximum UDMA 33 i think.. and the shop worker told us that maxtor 40 gig 7200 rpm must have 66 and above..is that true?

 

[Toejam31]

No. That's not true.

That sounds like more of a Mobo or a BIOS issue, if the drive could not be detected. That has nothing to do with the ATA standard.

You do have to use an 80 conductor <i>cable</i> for a device to run at ATA-66 or better. But a 40 conductor cable won't keep the drive from being detected correctly, even if the drive is running at ATA-33.

ATA standards are backwards-compatible ... the shop worker didn't know that he was talking about. Why am I not surprised?

<A HREF="http://www.seagate.com/support/kb/disc/ata_to_ultraata66.html" target="_new">http://www.seagate.com/support/kb/disc/ata_to_ultraata66.html</A>

The information in the article also applies to newer standards, such at ATA-100 and ATA-133.

Toejam31

<font color=red>My Rig:</font color=red> <A HREF="http://www.anandtech.com/mysystemrig.html?rigid=6847" target="_new">http://www.anandtech.com/mysystemrig.html?rigid=6847</A>
____________________________________________________

<font color=blue>"Does history record any case in which the majority was right?" ... Robert A. Heinlein</font color=blue>

 

[Guest]

oh i see..thank you but anyway why maxtor 30 gig is detected and the 40 gb not?
why must i get a new cable for 40 gig?

 

[Arrow]

If your motherboard is ATA33 only anyway, then there isn't really a point in getting a newer (ATA66) cable. As Toejam said, the reason as to why the 30GB may be recognized and the 40GB may not is probably due to a motherboard or BIOS limitation. Some boards or BIOSes will have trouble recognizing drives beyond a certain size. There are ways around this, such as utilities to enable support of larger disks, from the manufacturer of the hard drive.

Rob
Please visit <b><A HREF="http://www.ncix.com/canada/index.cfm?affiliateid=319048" target="_new">http://www.ncix.com/canada/index.cfm?affiliateid=319048</A></b>

 

[lhgpoobaa]

many older bios'es cant detect new large capacity drives.
i came accross this problem when i tried putting a 40gig drive into a 440LX mobo.
apparently anything over 33.8Gb cauzed it to lockup.

also, if you have a fast drive on a ata33 cable the MAX data flow rate is 33mb/sec, so if for example your drive is transfering at 25-30mb/sec, that only leaves a few mb for the other device (if any) attached to the same cable.
so if you are going to use a new fast drive on an old ata33 controler, it would help if its alone on an ide channel.


OEMs selling "High End"PCs with integrated video will be forced into Q3tournaments using a TNT2M64!

 

[Guest]

oh i c..thanks a lot..
the myth is solved hoho