Messages in this thread | | | Date | Wed, 2 Jan 2002 18:21:25 +0100 (CET) | From | Krzysztof Oledzki <> | Subject | Re: Two hdds on one channel - why so slow? |
| |
On Tue, 1 Jan 2002, Brian wrote:
> This is an inherent quirk (SCSI folks would say brain damage) in IDE. > > Only one drive on an IDE chain may be accessed at once and only one > request may go to that drive at a time. Therefore, the maximum you could > hope for in that test is half speed on each. Throw in the overhead of > continuously hopping between them and 12MB is no surprise.
So?!? This ATA100 and ATA133 standards do not make any sens? It is not possible to have more than 66 MB/sec with on drive and is seems that it is not possible to use more than ~30MB/sek of 100 or 133 MB/sec ATA100/133 bus speed with two HDDs. Oh :(((
Another question - why ATA100/ATA66 HDDs are so slow with UDMA33? With new IBM 60 GB IC35L060AVER07-0 I have much more than 33 MB/sec with ATA100 and only 24 MB/sec with UDMA33 (Asus P2B with IntelBX). New 80GB Seagates (Baracuda IV) have the same problem.
Best regards,
Krzysztof Oledzki
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |