On Mon, 03 Apr 2000, Moe wrote:

Hello All, Question for the experts out there. Whats the difference between the UDMA 66 drives vs ATA 66? I picked up a UDMA 66 for $135(20GB, 2mb buffer, 7200rpm). Has anyone on this list using this type of udma drive. Is the ATA 66 better? Why or why not?

This 66 MB/sec transfer rate is similar with scsi. My purpose for this drive for webhosting small sites using the SuSe 6.3.

Any extra info will be greatly appreciated...

I use a WD 20 gig UDMA66 drive and it works fine. I can get nowhere near 66mb/sec transfers though. About 28 mb is the max. If you need the 66mb transfers without the processor overhead use scsi. Not being an expert I will let others answer the remainder of your questions ;-) -- Bob F EMail FBob@wt.net A Truly Wise Man Never Plays Leapfrog With A Unicorn... -- To unsubscribe send e-mail to suse-linux-e-unsubscribe@suse.com For additional commands send e-mail to suse-linux-e-help@suse.com Also check the FAQ at http://www.suse.com/Support/Doku/FAQ/

* Moe (dr1moe@yahoo.com) [20000404 01:20]:

difference between the UDMA 66 drives vs ATA 66? I

Not really. In essence those are two names for the same thing.

This 66 MB/sec transfer rate is similar with scsi.

Well, only if your mobos chipset does support UDMA66 *and* you use the special ATA66 cable. And even then not quite :) There's currently *no* ATA drive on this planet that even gets near that transfer rate (only between the drive controllers cache and the mobo). The best of the current drives get nearly 30 MB, but that's the most. And as ATA drives can't disconnect from the bus in order to to let other drives receive their commands, the theoretical maximum of 66 MB/sec will not be utilized for quite some time to come. So you could have saved even further if there had been an UDMA33 drive with the same capacity available. ATA66 is mainly a marketing vehicle, invented to let ATA speeds approx. match SCSI rates on paper and to get users to upgrade their hardware. Philipp -- Philipp Thomas SuSE GmbH, Schanzaecker Str. 10, D-90443 Nuremberg, Germany #define NINODE 50 /* number of in core inodes */ #define NPROC 30 /* max number of processes */ -- Version 7 UNIX fuer PDP 11, /usr/include/sys/param.h -- To unsubscribe send e-mail to suse-linux-e-unsubscribe@suse.com For additional commands send e-mail to suse-linux-e-help@suse.com Also check the FAQ at http://www.suse.com/Support/Doku/FAQ/

Hi Moe & All, Moe wrote, <snip>

Question for the experts out there. Whats the difference between the UDMA 66 drives vs ATA 66? I picked up a UDMA 66 for $135(20GB, 2mb buffer, 7200rpm). Has anyone on this list using this type of udma drive. Is the ATA 66 better? Why or why not?

This 66 MB/sec transfer rate is similar with scsi. My purpose for this drive for webhosting small sites using the SuSe 6.3.

Any extra info will be greatly appreciated...

<snip> Here is a URL with the info you are after.... http://www.tomshardware.com/ & the heading you need to scroll down & find is...... "Bus Master DMA Drivers - Just An Illusion," or... http://www.tomshardware.com/storage/97q3/970829/index.html *BFN* Greek Geek :-) Your society will be sought by people of taste and refinement. -- To unsubscribe send e-mail to suse-linux-e-unsubscribe@suse.com For additional commands send e-mail to suse-linux-e-help@suse.com Also check the FAQ at http://www.suse.com/Support/Doku/FAQ/