From: "Richard Fish" <[EMAIL PROTECTED]> Subject: Re: [gentoo-user] SATA tuning ? Date: Tue, 15 Aug 2006 21:47:20 -0700
> Moving this back to gentoo-user, as I accidentally replied off list. > > Meino, please don't CC me directly on replies. I'll read them on the list... ...sorry...my fault...bu the previous mail was a private one to me... > On 8/15/06, Meino Christian Cramer <[EMAIL PROTECTED]> wrote: > > > > WHen doing things, which mixes higher CPU-loads with massive hd > > > > utilization, things are going slow (compilation of Blender for > > > > example). > > > > > > Ok, let's try to test that. We'll start by saturating your CPU(s). > > > On one terminal start "bzip2 -9 < /dev/urandom >/dev/null". > > > > This commandline puts a BIG SMILE onto my face ! Yes, this is as > > simple as it is genious!!! Great! Really a nice CPU barbeque ! > > > > > (If you > > > have multiple processors, start one of these bzip2 commands on one > > > terminal for each processor you have). > > > > > > Then on another, repeat the "hdparm -Tt /dev/sda" > > > > These are the results __without__ the CPU roaster: > > > > solfire:Mail/vim>sudo hdparm -tT /dev/sda > > /dev/sda: > > Timing cached reads: 2996 MB in 2.00 seconds = 1499.13 MB/sec > > Timing buffered disk reads: 174 MB in 3.01 seconds = 57.79 MB/sec > > > > and this are the results __with__ the CPU roaster: > > > > solfire:/home/mccramer>sudo hdparm -Tt /dev/sda > > solfire:/home/mccramer>sudo hdparm -Tt /dev/sda > > /dev/sda: > > Timing cached reads: 2160 MB in 2.10 seconds = 1030.12 MB/sec > > Timing buffered disk reads: 174 MB in 3.03 seconds = 57.41 MB/sec > > > > > > The chached reads dropped by ~469MByte/s. The buffered reads are > > nearly the same. > > The buffered reads are all we care about. They are the actual reads > from the disk to RAM. The cached reads is just a repeated read of the > same sector of the disk, so today is really just a test of your memory > bandwidth. Since we are loading memory and the CPU pretty heavily for > this test, and significant drop is to be expected. Ok...sounds good -- in the sense of: It seems, that I have no hardware problem anywhere in my Linux box... > So, it is not CPU utilization that is hurting your performance. ( :) imaging the above sentence *WITHOUT* the current context :) ) This is the eigth wonder of the world...the first time when CPU load does *not* hurt system performance! Oh yeah! I will send all my render tasks to the...floppy controller, hahahahahahaa :)))))) (sorry could not resist...I am a little daft this morning as it seems :O)) > You mentioned problems compiling. The most likely case I can think of > is that you do not have enough memory, and are inducing the system to > swap. Hmmm...1GByte Dualchannel-RAM should be enough for compiling Blender (for example). > Indeed when compiling most programs, you should see very little > if any disk activity. My SATA disk (Seagate ST3200827AS) is heavily shakeing its head when compiling... > This is particularly suspect if you have > something like MAKEOPTS=-j4. Yes, normally I use "make -j 4" for useing both cores. May be I foolishly forget something to switch on or off in my BIOS while migrating from PATA to SATA ? The only PATAs in my system is a Plextor CD reader/burner and a LG DVD reader/burner on IDE1 (scnd. channel). My mobo is a ASUS AV8 with AMI BIOS (upgraded to the "newest" version I could find on the net). > Regards, > -Richard > -- > gentoo-user@gentoo.org mailing list > -- gentoo-user@gentoo.org mailing list
