ATA 33 / 66

3 replies [Last post]
Phil Smith
Joined: Aug 19 1999

I have just purchased the DC10 Plus. I need a decent sized HDD because 1 gig is not enough. I have a Seagate 3.2 gig (ST33210A Ultra UDMA 5400 rpm) as the master drive and use to hold all my programmes. Then as a slave, video editing, I have my 4 year old 1 gig drive. My questions are 1) I have been told that my chaintech (super socket 7 one year old) will not support ATA 66 and I will therefore have to settle for ATA 33, therefore is ATA 33 good enough for data transfer and is there a big difference between ATA 33 and 66. 2) Does it make any difference whether you choose 5400rpm or 7200rpm, or is the difference not really noticeable. 3) I have been told to have each of my HDD on master with my CD Rom drive and ZIP drive as slaves, what is wrong with having the HDD's as master and slave, if its data transfer will I really notice the difference bearing in mind a shoot in Hi8 and output to VHS.

Having tested my present drives with the DC10 plus it came up with the following results.
3.2 gig drive
write 7584 kb/s read 8947 kb/s
video data rate 4674 kb/s.

1 gig drive
write 4121 kb/s read 4118 kb/s
video data rate 2574 kb/s

Having captured using the 1 gig drive, edited and output to VHS tape the results were quite good except for a bit of jerky-ness now and then, which I assume is down to the drive and data transfer.

Any advice on the above would be most appreciated.


Joined: Jul 6 1999

ATA-66 drives are not a lot faster than ATA-33... but they were getting to the point where two drives together could exceed the capabiltiy of the cable they shared.

Of course, this weeks drive will be faster than last weeks drive; and they all seem to be ATA-66 now whether they need it or not.

As you make clear, your existing drives which are relatively small, and probably therefore quite old, are quite fast enough.

Indeed, your problem may be to find any disk that isn't ATA-66. The ATA-66 disks use a different ribbon cable (though the connectors are the same) - with extra wires to screen out crosstalk.

You should really use the new type of cable if you have an ATA-66 disk. The other problem is that your motherboard may not recognise an ATA-66 disk properly... but I am not an expert on that bag of worms.

There was a message and a whole chain of replies on this subject a few weeks ago, including some prettyu strident stuff from Bob Crabtree in person.



Joined: Sep 14 1999

I was all set to post a similar question so I'll put it here and share your replies.
I do not understand UDMA 33 and UDMA 66.
System is Pentium 2 350 Mhz 6 Gb boot 8Gb video Bx motherboard.
I am told this system is UDMA 33 and will not support 66.
Can I convert to 66 ?
Do I need to anyway ?
If so how do I convert ?
I have seen a 17Gb UDMA 66 on offer £99 + vat
Will this work on 33 ?
I didn't have all this confusion when I had a BBC 'B' and a 40 track floppy !!!
Please help.
Many thanks.

Joined: Jul 6 1999

1. If you buy a new disk it will be ATA-66, they don't make ATA-33s any more.

2. No, you don't actually need ATA-66.

3. If you use an ATA-66 drive you must use an ATA-66 cable. The new cable is plug compatible with the old type, but the ribbon has 80 wires insted of 40. The extra wires are used for screening.

4. Your motherboard will probably not recognise ATA-66 disk properly, in which case you have two choices:
a) get a bios upgrade for the motherboard
b) get a utility from the disk manufacturer
which you run to tell the disk to report
itself as an ATA-33.

I would recommend b)