ATA Hard Drive on EIDE MotherBoard?

[edmundym]

Hi:
I would like to add a bigger 40G ATA/100 to my old P2 450 motherboard w/ EIDE interface. Will this work?

Assume if it the ATA is backward compatible, what about the actual data transfer performace on this combination?

Is it necessary to add an ATA controller to fully utilize the ATA/100 performance?

Thanks in advance.

 

[CitrixEngineer]

Short answers;

1. Yes it will work.
2. The data transfer will be whatever the EIDE interface can handle (Max 30MB/Sec, although half this is more likely).
3. Yes.

Long explanation (because I like talking about this technology )

The ATA interface is kind of like a client/server environment. The client (the disk) and the server (the controller) must both know all protocol (ATA) details in order to achieve full functionality, but will perform at the lowest common denominator otherwise.

ATA stands for Advanced Technology Attachment (AT is the name originally given to IBM 286 computers).

EIDE, (Expanded or Enhanced Integrated Drive Electronics) was an extension to the ATA interface, introduced or at least adopted around 1994 (typically in 486 and early Pentium machines). It gave access to disks larger than 528Mb, using a Logical Block Address (LBA) and provided support for DMA (Direct Memory Access/Addressing) and ATAPI. ATAPI is a Packet Interface for Optical drives, like CD-ROMs and DVD-ROMs. EIDE is also known as ATA2 or fast ATA.

ATA-33 is really ATA3, and ATA-66/100/133 are simply references to the theoretical fastest possible data transfer spikes in MB/sec that the devices, together with compatible controllers, are capable of. In reality, few show sustained DTRs faster than about 30MB/sec. The UDMA (Ultra DMA) drives simply refer to the revision of the DMA protocol and, like ATA, depend on the client and server knowing all the rules in the table, otherwise they will just use the ones they can agree on.

Ultra is just a nice, buzzy word that's been linked to SCSI devices for a while, and has now been adopted by IDE drives. It's meaningless except as a marketing term.


Back to the issue;

You may notice a speed difference without the use of a compatible controller, since newer drivers spin faster, have faster access times and typically have large cache buffers.

However, a compatible controller will certainly make a difference you will notice.


I hope this helps. CitrixEngineer@yahoo.co.uk

 

[CitrixEngineer]

Addendum;

It's possible your BIOS will not recognise disks bigger than 32GB. Come to think of it, if you're using an EIDE controller, it may not recognise more than 8GB.

That doesn't negate what I said above - it will work. You just might not get to see all of the disk :-( CitrixEngineer@yahoo.co.uk

 

[cdogg]

Citrix is right that older BIOS's may not recognize more than 8GB. It has to support interrupt 13 extensions. If not, you'll need to flash the BIOS to a later version which does. I think this was mainly a problem with older chipsets dating back to early pentiums and the first P2's.

http://support.microsoft.com/default.aspx?scid=kb;en-us;Q153550

Also, make sure you format the drive as FAT32 and that your OS supports the partition size (must have Win95 OSR2 or later). More on this here:

http://support.microsoft.com/default.aspx?scid=kb;en-us;Q154997

 

[edmundym]

Thanks all for the detail info. I think this is pretty clear to me now.

Ed