From mboxrd@z Thu Jan 1 00:00:00 1970 From: gtaylor@tnetconsulting.net (Grant Taylor) Date: Mon, 23 Apr 2018 22:32:26 -0600 Subject: [TUHS] /dev/drum In-Reply-To: <9a5e49bb-f235-4b87-445b-1532d8facd2f@update.uu.se> References: <9a5e49bb-f235-4b87-445b-1532d8facd2f@update.uu.se> Message-ID: On 04/23/2018 05:44 PM, Johnny Billquist wrote: > But this whole optimization for swap based on transfer speeds makes no > sense to me. The dominating factor in spinning rust is seek times, and > not transfer speed. If you place the swap at one end of the disk, it > won't matter much that transfers will be faster, as seek times will on > average be much longer, and that will eat up any transfer gain ten times > over before even thinking. (Unless all your disk ever does is swapping, > at which time the heads can stay around the swapping area all the time.) I wonder if part of the (perceived?) performance gain was from the likelihood that swap at one end of the drive meant that things could be contiguous. Seek, lay down / pick up a large (or at least not small) number of sectors, and seek back. I had always assumed that the outer edge (what I thought was the end of the disk) was faster than the inner edge (what I thought was the beginning of the disk) because of geometry. However, as Ronald stated, hard drives were constant angular density. Thus negating what I originally thought about speed. -- Grant. . . . unix || die -------------- next part -------------- A non-text attachment was scrubbed... Name: smime.p7s Type: application/pkcs7-signature Size: 3982 bytes Desc: S/MIME Cryptographic Signature URL: