Ultra DMA 33's and 66's

[mamehakase]

Some of the advanced MB's like the Abit ZM6 support DMA33. Does that mean that if I hook up a DMA66 HDD to it, it'll at least yield a DMA33 performance? I'm quite concerned, although it is in my future plans to go purchase a Promise 66 adapter card.

[Bleeding Edge]

Ripped from Seagate:


Is Ultra ATA/66 backward compatible with my current Ultra ATA/33 system?

Yes. Ultra ATA/66 is backward compatible with all Ultra ATA/33 systems, but it will be limited in its transfer mode to the Ultra ATA/33 (Ultra DMA Mode 2 - 33 Mbytes/sec) or PIO Mode 4 (16.6 Mbytes/sec). Ultra ATA/66 hard drives are 100 percent backward compatible with both Ultra ATA/33 and DMA and with existing ATA (IDE) hard drives, CD-ROM drives, and host systems. The Ultra ATA/66 protocol and commands are designed to be compatible with existing ATA (IDE) devices and systems. Although a new 40-pin, 80-conductor cable is required for Ultra ATA/66, the chip set pin connector remains the same at 40. Hard drives that support Ultra ATA/66 also support Ultra ATA/33 and legacy ATA (IDE) specifications

Additional information:
http://www.seagate.com/support/disc/faq/ultra_ata_66.shtml

[mamehakase]

Thanks!! That was very much appreciated. Does anyone know of any motherboards that are already out in the market or about to bust out in the market that support Ultra DMA 66?

[Bleeding Edge]

We're waiting for the Camino chipset from Intel. This will let the new motherboards support UDMA/66, AGP 4X, faster memory among other features.

I thouhght I saw a motherboard with a VIA chipset that supports UDMA/66 during my searches. I can't seem to locate the info again.

[MR COMPUTER]

PC Chips M598 and M748MR say they are. i have yet to try it. http://www.sysopt.com/forum/wink.gif

[This message has been edited by MR COMPUTER (edited 05-12-99).]

[Helly Hansen]

Hey Guys,
No one seems to know or talk about this but UDMA/66 is only available with an 80 conductor cable. Still 40 Pin! but 80 conductor! Only one company is currently manufacturing the cable. With the proper drivers and cable you can crank UDMA/66 or Ultra ATA/66 out of almost any UDMA/33 or Ultra ATA/33 controller. Of course if you got the proper controller you would probably see a little improved performance.

Brandon Sandifer
Sandifer Peripherals
www.gowiththebest.com/newsite.shtm

[steves]

Anyone ever trust anything PC Chips say http://www.sysopt.com/forum/wink.gif

80 Conductors = Normal EIDE + 40 interleaved earth cables to reduce interference.

Anand (www.anandtach.com) reckons that 66 offers very little improvement for 5400rpm drives as they can't supply the data that quick. 7200rpm drives may shown some improvement in real world terms, but the real improvements will come when 10,000rpm drives are commonplace.

[Bleeding Edge]

Helly Hanson. Perhaps you missed the link I provided above. http://www.seagate.com/support/disc/faq/ultra_ata_66.shtml
The information is good. It also leads to this link which further details UDMA/66. http://www.seagate.com/support/disc/papers/ultra_ata.shtml

[raihanan]

I just bought a retail 20.4GB Western Digital drive over the weekend. It came with an 80 conductor cable inside, but I'm still using ATA/33 until I can figure out how to get 66.

-- Jeff

[Helly Hansen]

Hey Guys,
Yes I read the link, Guy with the Western Digital, got to Western Digital's website and download the UDMA/66 drivers. (www.wdc.com)

Good Luck!
Brandon Sandifer
Sandifer Peripherals
www.gowiththebest.com/newsite.shtm

[ENVY]

the 80 pin should always come with the ata 66.there is more than 1 company that makes them.one link is www.ultracable.com (http://www.ultracable.com) .I use these on my ata33 and saw a nice performance increase plus it helps control signal interference.

[This message has been edited by ENVY (edited 05-12-99).]

[mamehakase]

Correct me if I'm wrong. UDMA66 is not supported by current motherboards. This is not necessarily a cable issue, although the special ribbon cables are necessary. Currently, the only I/O card that supports UDMA-66 is the Promise 66. From what I understand, no amount Bios flashing with updates is going to upgrade current motherboards to UDMA-66 support, so you have to be willing to spend $57-$70 on an I/O card to get UDMA-66 performance.

[BBA]

Helly, if you read the articles posted, then you would have noticed the requirements for Ultra ATA/66 UDMA2/66 are: Ultra ATA/66 MB, UltraATA/66 drive, Ultra ATA/66 80 conductor 40pin connectors and Ultra ATA busmaster drivers.

This means all the above are needed, ommit one and you only get UDMA2/33!

With the current Intel BX/GX/FX/TX/LX,etc... chipsets, you will only get UDMA2/33. Period!

If you use a VIA chipset, you might get Ultra ATA/66 but you get a cheap peice of junk mb that wont do anything but conflict with itself, not to mention any hardware you put on it!

So for now, be happy with UDMA2/33, which doesn't even perform better than PIO mode4 anyways except in rare moments when the correct data needed was 'accidentally' pre-cached and is then bursted to the mb. This is a pretty rare occurence, as attested by multiple drive testing sessions.

In other words, it wont cure the worlds diseases and it's a bigger sales promotional gimmick than performance enhancer!


BBA