Messages in this thread | | | Date | Thu, 10 Dec 1998 19:59:45 GMT | From | "Stephen C. Tweedie" <> | Subject | Re: SMP 2.1.131: SCSI performance extremely poor vs. IDE |
| |
Hi,
On 08 Dec 1998 16:31:07 -0800, Ben Gertzfield <che@debian.org> said:
> I've received a report of extremely poor SCSI performance in the late > 2.1.x kernels and verified this under 2.1.131.
> I tested this by untarring the mozilla source onto the local hard > drive, syncing, and rm -rf ing it.
> The mozilla source is 91.6 megabytes untarred.
> The results are astounding:
This "benchmark" is so full of variables that it is utterly meaningless on its own. You are running on two different systems. Is performance repeatable or not? How much memory is in each system? How fragmented are the existing disks? How much of the data is in the buffer cache when you do the rm?
> This is, frankly, terrible. Since when is IDE three times faster than > ultra-wide SCSI?
IDE command setup latency is a _lot_ lower than SCSI's, especially with UDMA. If all you are measuring is random read seek rates, then yes, IDE can quite easily be faster than SCSI.
--Stephen
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/
| |