On 21 May 2003, Arjan van de Ven wrote: > On Wed, 2003-05-21 at 22:22, Atul Chitnis wrote: > > On 21 May 2003, Arjan van de Ven wrote: > > > /dev/hda: > > Timing buffer-cache reads: 128 MB in 0.50 seconds =256.00 MB/sec > > Timing buffered disk reads: 64 MB in 18.92 seconds = 3.38 MB/sec > > this is WAAAY too low. Should be like 10x that. I agree. I totally missed that - I ran it, cut and pasted without paying attention. Must have been some cron process smoking something potent there the first time round. I just ran it again - here is what I got: [root@xxxxxx] /etc/sysconfig# hdparm -Tt /dev/hda /dev/hda: Timing buffer-cache reads: 128 MB in 0.52 seconds =246.15 MB/sec Timing buffered disk reads: 64 MB in 2.58 seconds = 24.81 MB/sec I must admit though that in both cases I ran it under X, with Joe Satriani giving xmms something to think about. So this is not exactly a scientific test ;-) I turned on 32 bit IO (-c3) but didnt notice any difference - hdparm -Tt results are identical. Nope - unless it is something periodical that is killing disk performance, I'd still think it is something X related. Meaning that what I am *perceiving* is low performance (jerky window movement, delayed menu popup, etc.), while the machine may possibly not be running any slower otherwise. Doh! ;-) Ah, just to make sure that the problem isn't anything else, I killed xmms and anything else that could make a difference (but remaining in X) and ran tests again - no difference. hdparm -Tt gave about 4% more throughput, but that would have been expected.. Hmmm - maybe its gremlins. IAC, its not like the machine is unusable (I don't move windows for a living ;), it's just disconcerting, and so far it seems to be just me facing this (which is a lousy sample size). I am sure you guys will stumble across something over time that will make my day. Like maybe Mike getting new and improved ATI drivers into Xfree86 ;-) If you want me to run any specific tests or tweaks, let me know. Atul -- ------------------------------------------- Atul Chitnis | achitnis@xxxxxxxxxxx Exocore Consulting | http://www.exocore.com Bangalore, India | +91 (80) 344-0397 -------------------------------------------
