Re: SATA disk detected as IDE? SOLVED
On 20100702_235713, Stan Hoeppner wrote: Henrique de Moraes Holschuh put forth on 7/2/2010 9:24 PM: On Fri, 02 Jul 2010, Stan Hoeppner wrote: software... What is NCQ? (in this context, of course) What is A way to have various requests in flight and let the disk itself order them to get better performance. Whether it helps performance or not depends on the IO workload, the kind of device, and the quality of the NCQ firmware in the device. ATA_NCQ_HORKAGE list? The only hit that I get on this string in Google I was involved in this confusion at an earlier stage. I'm still confused: What, exactly, do I type into Google to gain a URL of this resource? Does it REALLY involve HORKAGE with an H? And underscores? Presumably this is a well know resource. But only to those who already know, and not to me. TIA It is a blacklist for defective products that misbehave when NCQ is enabled, or which have such a poor excuse of an NCQ implementation that one should never enable it. You mangled your quoting. I didn't ask these questions, another OP did. I answered them. Or, at least, someone else answered the first and I answered the second. And again, it's not ATA_NCQ_HORKAGE but rather ATA_HORKAGE_NONCQ. No real foul. I'm just correcting the record for the various archives. -- Stan -- Paul E Condon pecon...@mesanetworks.net -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20100704150456.gh21...@big.lan.gnu
Re: SATA disk detected as IDE? SOLVED
On Sun, 04 Jul 2010 09:04:56 -0600, Paul E Condon wrote: On 20100702_235713, Stan Hoeppner wrote: ATA_NCQ_HORKAGE list? The only hit that I get on this string in Google I was involved in this confusion at an earlier stage. I'm still confused: What, exactly, do I type into Google to gain a URL of this resource? Does it REALLY involve HORKAGE with an H? And underscores? Presumably this is a well know resource. But only to those who already know, and not to me. Review your /usr/src/linux/drivers/ata/libata-core.c and search for ATA_HORKAGE_NONCQ string to find a list of blacklisted devices in which kernel avoids enabling NCQ for some reason (slow/broken). Greetings, -- Camaleón -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/pan.2010.07.04.15.44...@gmail.com
Re: SATA disk detected as IDE? SOLVED
On Sunday 04 July 2010 16:04:56 Paul E Condon wrote: On 20100702_235713, Stan Hoeppner wrote: Henrique de Moraes Holschuh put forth on 7/2/2010 9:24 PM: On Fri, 02 Jul 2010, Stan Hoeppner wrote: software... What is NCQ? (in this context, of course) What is A way to have various requests in flight and let the disk itself order them to get better performance. Whether it helps performance or not depends on the IO workload, the kind of device, and the quality of the NCQ firmware in the device. ATA_NCQ_HORKAGE list? The only hit that I get on this string in Google I was involved in this confusion at an earlier stage. I'm still confused: What, exactly, do I type into Google to gain a URL of this resource? Does it REALLY involve HORKAGE with an H? And underscores? Presumably this is a well know resource. But only to those who already know, and not to me. Try reading the bottom of your own email (and now beneath this), where it correctly quotes Stan. He says that it should be: ATA_HORKAGE_NONCQ. Lisi It is a blacklist for defective products that misbehave when NCQ is enabled, or which have such a poor excuse of an NCQ implementation that one should never enable it. You mangled your quoting. I didn't ask these questions, another OP did. I answered them. Or, at least, someone else answered the first and I answered the second. And again, it's not ATA_NCQ_HORKAGE but rather ATA_HORKAGE_NONCQ. No real foul. I'm just correcting the record for the various archives. -- Stan -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/201007041710.44267.lisi.re...@gmail.com
Re: SATA disk detected as IDE? SOLVED
On 20100704_154414, Camale?n wrote: On Sun, 04 Jul 2010 09:04:56 -0600, Paul E Condon wrote: On 20100702_235713, Stan Hoeppner wrote: ATA_NCQ_HORKAGE list? The only hit that I get on this string in Google I was involved in this confusion at an earlier stage. I'm still confused: What, exactly, do I type into Google to gain a URL of this resource? Does it REALLY involve HORKAGE with an H? And underscores? Presumably this is a well know resource. But only to those who already know, and not to me. Review your /usr/src/linux/drivers/ata/libata-core.c and search for ATA_HORKAGE_NONCQ string to find a list of blacklisted devices in which kernel avoids enabling NCQ for some reason (slow/broken). On my computer /usr/src/linux/ directory does not exist. I do have deb-src lines in my /etc/apt/sources.list, but have not used them much. Once I downloaded source for find and made a modification and rebuilt in order to implement a personal preference. But now I'm looking at debian.org and having difficulty figuring out what to do to get my /usr/src/linux directory created and populated. Can someone recommend a howto for deb-src? Is there a distinction between sid and testing in deb-src? -- Paul E Condon pecon...@mesanetworks.net -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20100704210135.gi21...@big.lan.gnu
Re: SATA disk detected as IDE? SOLVED
Paul E Condon put forth on 7/4/2010 4:01 PM: On my computer /usr/src/linux/ directory does not exist. That's because you don't compile your own kernels (or at least on that PC). Google for ATA_HORKAGE_NONCQ -- Stan -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/4c30fb22.6070...@hardwarefreak.com
Re: SATA disk detected as IDE? SOLVED
On 2010-07-04 23:20 +0200, Stan Hoeppner wrote: Paul E Condon put forth on 7/4/2010 4:01 PM: On my computer /usr/src/linux/ directory does not exist. That's because you don't compile your own kernels (or at least on that PC). There is no reason to build kernels under /usr/src/linux. Any directory where you have write access is fine. Sven -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/87iq4vym2t@turtle.gmx.de
Re: SATA disk detected as IDE? SOLVED
On Du, 04 iul 10, 15:01:35, Paul E Condon wrote: But now I'm looking at debian.org and having difficulty figuring out what to do to get my /usr/src/linux directory created and populated. Can someone recommend a howto for deb-src? The Linux kernel is special, because the source is packaged as a regular package, named linux-source-version. Just install that. You may also want to install the corresponding linux-doc-version package. Is there a distinction between sid and testing in deb-src? Of course. The deb-src lines should be analogue to your regular deb lines, but beware: by default 'apt-get source package' will get the source for the most recent version regardless of any kind of pinning. Regards, Andrei -- Offtopic discussions among Debian users and developers: http://lists.alioth.debian.org/mailman/listinfo/d-community-offtopic signature.asc Description: Digital signature
Re: SATA disk detected as IDE? SOLVED
On Sun, 04 Jul 2010 15:01:35 -0600, Paul E Condon wrote: On 20100704_154414, Camale?n wrote: Review your /usr/src/linux/drivers/ata/libata-core.c and search for ATA_HORKAGE_NONCQ string to find a list of blacklisted devices in which kernel avoids enabling NCQ for some reason (slow/broken). On my computer /usr/src/linux/ directory does not exist. (...) Okay, okay... look here then: http://lxr.free-electrons.com/source/drivers/ata/libata-core.c#L4287 Greetings, -- Camaleón -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/pan.2010.07.04.21.43...@gmail.com
Re: SATA disk detected as IDE? SOLVED
On 07/04/2010 04:43 PM, Camaleón wrote: On Sun, 04 Jul 2010 15:01:35 -0600, Paul E Condon wrote: On 20100704_154414, Camale?n wrote: Review your /usr/src/linux/drivers/ata/libata-core.c and search for ATA_HORKAGE_NONCQ string to find a list of blacklisted devices in which kernel avoids enabling NCQ for some reason (slow/broken). On my computer /usr/src/linux/ directory does not exist. (...) Okay, okay... look here then: http://lxr.free-electrons.com/source/drivers/ata/libata-core.c#L4287 One other issue is that this is new in 2.6.33. (Which is why I didn't find it in 2.6.32.) -- Seek truth from facts. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/4c31033f.6020...@cox.net
Re: SATA disk detected as IDE? SOLVED
Ron Johnson put forth on 7/4/2010 4:55 PM:
On 07/04/2010 04:43 PM, Camaleón wrote:
On Sun, 04 Jul 2010 15:01:35 -0600, Paul E Condon wrote:
On 20100704_154414, Camale?n wrote:
Review your /usr/src/linux/drivers/ata/libata-core.c and search for
ATA_HORKAGE_NONCQ string to find a list of blacklisted devices in
which kernel avoids enabling NCQ for some reason (slow/broken).
On my computer /usr/src/linux/ directory does not exist.
(...)
Okay, okay... look here then:
http://lxr.free-electrons.com/source/drivers/ata/libata-core.c#L4287
One other issue is that this is new in 2.6.33. (Which is why I didn't
find it in 2.6.32.)
ATA_HORKAGE_NONCQ isn't new to 2.6.33. I don't know how long it's been
around, but it does go back quite a ways in 2.6.x. Here it is in 2.6.31.1,
which is the oldest source I have sitting around.
/usr/src/linux-2.6.31.1/drivers/ata$ grep ATA_HORKAGE_NONCQ libata-core.c
if (dev-horkage ATA_HORKAGE_NONCQ) {
{ WDC WD740ADFD-00, NULL, ATA_HORKAGE_NONCQ },
{ WDC WD740ADFD-00NLR1, NULL, ATA_HORKAGE_NONCQ, },
{ FUJITSU MHT2060BH, NULL, ATA_HORKAGE_NONCQ },
{ Maxtor *, BANC*,ATA_HORKAGE_NONCQ },
{ Maxtor 7V300F0, VA111630, ATA_HORKAGE_NONCQ },
{ ST380817AS, 3.42, ATA_HORKAGE_NONCQ },
{ ST3160023AS,3.42, ATA_HORKAGE_NONCQ },
{ OCZ CORE_SSD, 02.10104, ATA_HORKAGE_NONCQ },
{ ST31500341AS, SD15, ATA_HORKAGE_NONCQ |
{ ST31500341AS, SD16, ATA_HORKAGE_NONCQ |
{ ST31500341AS, SD17, ATA_HORKAGE_NONCQ |
{ ST31500341AS, SD18, ATA_HORKAGE_NONCQ |
{ ST31500341AS, SD19, ATA_HORKAGE_NONCQ |
{ ST31000333AS, SD15, ATA_HORKAGE_NONCQ |
{ ST31000333AS, SD16, ATA_HORKAGE_NONCQ |
{ ST31000333AS, SD17, ATA_HORKAGE_NONCQ |
{ ST31000333AS, SD18, ATA_HORKAGE_NONCQ |
{ ST31000333AS, SD19, ATA_HORKAGE_NONCQ |
{ ST3640623AS,SD15, ATA_HORKAGE_NONCQ |
{ ST3640623AS,SD16, ATA_HORKAGE_NONCQ |
{ ST3640623AS,SD17, ATA_HORKAGE_NONCQ |
{ ST3640623AS,SD18, ATA_HORKAGE_NONCQ |
{ ST3640623AS,SD19, ATA_HORKAGE_NONCQ |
{ ST3640323AS,SD15, ATA_HORKAGE_NONCQ |
{ ST3640323AS,SD16, ATA_HORKAGE_NONCQ |
{ ST3640323AS,SD17, ATA_HORKAGE_NONCQ |
{ ST3640323AS,SD18, ATA_HORKAGE_NONCQ |
{ ST3640323AS,SD19, ATA_HORKAGE_NONCQ |
{ ST3320813AS,SD15, ATA_HORKAGE_NONCQ |
{ ST3320813AS,SD16, ATA_HORKAGE_NONCQ |
{ ST3320813AS,SD17, ATA_HORKAGE_NONCQ |
{ ST3320813AS,SD18, ATA_HORKAGE_NONCQ |
{ ST3320813AS,SD19, ATA_HORKAGE_NONCQ |
{ ST3320613AS,SD15, ATA_HORKAGE_NONCQ |
{ ST3320613AS,SD16, ATA_HORKAGE_NONCQ |
{ ST3320613AS,SD17, ATA_HORKAGE_NONCQ |
{ ST3320613AS,SD18, ATA_HORKAGE_NONCQ |
{ ST3320613AS,SD19, ATA_HORKAGE_NONCQ |
{ HTS541060G9SA00,MB3OC60D, ATA_HORKAGE_NONCQ, },
{ HTS541080G9SA00,MB4OC60D, ATA_HORKAGE_NONCQ, },
{ HTS541010G9SA00,MBZOC60D, ATA_HORKAGE_NONCQ, },
{ noncq, .horkage_on = ATA_HORKAGE_NONCQ },
{ ncq,.horkage_off= ATA_HORKAGE_NONCQ },
--
Stan
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Re: SATA disk detected as IDE? SOLVED
Paul E Condon put forth on 7/1/2010 6:47 PM: I'm lurking here, hoping to learn useful stuff about hard drive software... What is NCQ? (in this context, of course) What is ATA_NCQ_HORKAGE list? The only hit that I get on this string in Google is a link to this email to which I am responding. TIA I probably mistyped it Paul. Let's see... It's actually ATA_HORKAGE_NONCQ. Google that. -- Stan -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/4c2dfeaf.3090...@hardwarefreak.com
Re: SATA disk detected as IDE? SOLVED
On Fri, 02 Jul 2010, Stan Hoeppner wrote: software... What is NCQ? (in this context, of course) What is A way to have various requests in flight and let the disk itself order them to get better performance. Whether it helps performance or not depends on the IO workload, the kind of device, and the quality of the NCQ firmware in the device. ATA_NCQ_HORKAGE list? The only hit that I get on this string in Google It is a blacklist for defective products that misbehave when NCQ is enabled, or which have such a poor excuse of an NCQ implementation that one should never enable it. -- One disk to rule them all, One disk to find them. One disk to bring them all and in the darkness grind them. In the Land of Redmond where the shadows lie. -- The Silicon Valley Tarot Henrique Holschuh -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20100703022410.gc20...@khazad-dum.debian.net
Re: SATA disk detected as IDE? SOLVED
Henrique de Moraes Holschuh put forth on 7/2/2010 9:24 PM: On Fri, 02 Jul 2010, Stan Hoeppner wrote: software... What is NCQ? (in this context, of course) What is A way to have various requests in flight and let the disk itself order them to get better performance. Whether it helps performance or not depends on the IO workload, the kind of device, and the quality of the NCQ firmware in the device. ATA_NCQ_HORKAGE list? The only hit that I get on this string in Google It is a blacklist for defective products that misbehave when NCQ is enabled, or which have such a poor excuse of an NCQ implementation that one should never enable it. You mangled your quoting. I didn't ask these questions, another OP did. I answered them. Or, at least, someone else answered the first and I answered the second. And again, it's not ATA_NCQ_HORKAGE but rather ATA_HORKAGE_NONCQ. No real foul. I'm just correcting the record for the various archives. -- Stan -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/4c2ec329.6080...@hardwarefreak.com
Re: SATA disk detected as IDE? SOLVED
On 20100701_001335, Stan Hoeppner wrote: Anand Sivaram put forth on 6/30/2010 10:25 PM: Why do you say that it is detected as IDE. Normally IDE disks using I don't get this either. Nothing in anything he posted shows that the kernel is detecting this drive as IDE. Quite the contrary, it's being detected as a SATA device, and if he'd have shown dmesg output, it would clearly state so, but he did not. deprecated IDE driver are shown as hda, hdb etc. where as SATA and the same IDE disks with newer PATA driver are shown as sda, sdb etc. For you it is showing the disk as sda. Take a look at lspci -k to see which kernel driver is getting used. Also a very easy method to see the reading speed of the disk is You're talking about libata, the current all-in-one SATA/PATA/ATAPI driver. And yes, regardless of whether a drive is PATA or SATA, if it's under the control of libata, it will show up as /dev/sdx, or if it's a CD/DVD-ROM as /dev/srx. dd if=/dev/sda of=/dev/null bs=1M count=1024 This will read the first 1024MB of your disk. I think a good disk/controller gives you more than 70MB per second or so. That depends on many factors, the big one being whether the drive and controller both support NCQ, and if they both have a good implementation of it. Look at the ATA_NCQ_HORKAGE list to see a group of drives whose performance _drops_ considerably with NCQ enabled, or suffer other more serious problems with NCQ enabled such as filesystem corruption, data loss, etc. I'm lurking here, hoping to learn useful stuff about hard drive software... What is NCQ? (in this context, of course) What is ATA_NCQ_HORKAGE list? The only hit that I get on this string in Google is a link to this email to which I am responding. TIA Other factors affecting sequential read performance (dd) are the elevator used, and the nr_requests and read_ahead_kb settings. Bumping read_ahead_kb up from the default 128 to 512 or 1024 will produce a decent increase in sequential read performance, about 10-20%. For example, a quick test on one of my lower end systems produces a 16% increase in sequential read performance: /$ dd if=/dev/sda of=/dev/null bs=1M count=1024 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 16.8026 s, 63.9 MB/s /$ echo 1024 read_ahead_kb /$ dd if=/dev/sda of=/dev/null bs=1M count=1024 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 14.4375 s, 74.4 MB/s (This system only has only 384MB RAM so little to none of the performance increase was due to buffers/cache from the first dd run) _But_ a high read_ahead_kb setting causes a huge rise in the size of kernel I/O buffers, eating system memory like candy. This one test caused a 6 fold increase in my kernel buffer size, to over 260MB. Playing with read_ahead_kb for testing can be useful in measuring absolute hardware performance, but I wouldn't run day-to-day with a setting much higher than the default. There are some specific server applications where high read_ahead_kb is useful, such as streaming media servers, but they are few and far between. -- Stan -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/4c2c23ff.7010...@hardwarefreak.com -- Paul E Condon pecon...@mesanetworks.net -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20100701234757.gd21...@big.lan.gnu
Re: SATA disk detected as IDE? SOLVED
On Thu, 1 Jul 2010 17:47:57 -0600 Paul E Condon pecon...@mesanetworks.net wrote: ... I'm lurking here, hoping to learn useful stuff about hard drive software... What is NCQ? (in this context, of course) What is http://en.wikipedia.org/wiki/Native_Command_Queuing Celejar -- foffl.sourceforge.net - Feeds OFFLine, an offline RSS/Atom aggregator mailmin.sourceforge.net - remote access via secure (OpenPGP) email ssuds.sourceforge.net - A Simple Sudoku Solver and Generator -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20100701195655.d1452e8a.cele...@gmail.com
Re: SATA disk detected as IDE? SOLVED
Hello Amrit. One option of the BIOS of the motherboard was allowing use with much less speed, I don't understand how much how run this, because install XP CD don't detect any SATA disk but Linux treat disk as IDE, and now seems that runs really much more fast, more than twice. Josep El mié, 30-06-2010 a las 12:00 -0700, Amrit Panesar escribió: On 6/30/2010 11:38 AM, Josep M. wrote: Hello. I have a SATA HD, installed as SATA HD (not as ide in motherboard) and Debian squeeze detects me this as IDE. What can I do for change his? Appended there is is the output of hdparm and sdparm Thanks Josep -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/1277928856.3010.2.ca...@mail.navegants.net
Re: SATA disk detected as IDE? SOLVED
On 6/30/2010 1:14 PM, Josep M. wrote: Hello Amrit. One option of the BIOS of the motherboard was allowing use with much less speed, I don't understand how much how run this, because install XP CD don't detect any SATA disk but Linux treat disk as IDE, and now seems that runs really much more fast, more than twice. Josep El mié, 30-06-2010 a las 12:00 -0700, Amrit Panesar escribió: On 6/30/2010 11:38 AM, Josep M. wrote: Hello. I have a SATA HD, installed as SATA HD (not as ide in motherboard) and Debian squeeze detects me this as IDE. What can I do for change his? Appended there is is the output of hdparm and sdparm Thanks Josep No Problem Josep, anything to help a fellow Debian User. Thanks -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/4c2bdf3e.9020...@4195tech.com
Re: SATA disk detected as IDE? SOLVED
On Thu, Jul 1, 2010 at 05:50, Amrit Panesar apane...@4195tech.com wrote: On 6/30/2010 1:14 PM, Josep M. wrote: Hello Amrit. One option of the BIOS of the motherboard was allowing use with much less speed, I don't understand how much how run this, because install XP CD don't detect any SATA disk but Linux treat disk as IDE, and now seems that runs really much more fast, more than twice. Josep El mié, 30-06-2010 a las 12:00 -0700, Amrit Panesar escribió: On 6/30/2010 11:38 AM, Josep M. wrote: Hello. I have a SATA HD, installed as SATA HD (not as ide in motherboard) and Debian squeeze detects me this as IDE. What can I do for change his? Appended there is is the output of hdparm and sdparm Thanks Josep No Problem Josep, anything to help a fellow Debian User. Thanks -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/4c2bdf3e.9020...@4195tech.com I have a SATA HD, installed as SATA HD (not as ide in motherboard) and Debian squeeze detects me this as IDE. Why do you say that it is detected as IDE. Normally IDE disks using deprecated IDE driver are shown as hda, hdb etc. where as SATA and the same IDE disks with newer PATA driver are shown as sda, sdb etc. For you it is showing the disk as sda. Take a look at lspci -k to see which kernel driver is getting used. Also a very easy method to see the reading speed of the disk is dd if=/dev/sda of=/dev/null bs=1M count=1024 This will read the first 1024MB of your disk. I think a good disk/controller gives you more than 70MB per second or so.
Re: SATA disk detected as IDE? SOLVED
Anand Sivaram put forth on 6/30/2010 10:25 PM: Why do you say that it is detected as IDE. Normally IDE disks using I don't get this either. Nothing in anything he posted shows that the kernel is detecting this drive as IDE. Quite the contrary, it's being detected as a SATA device, and if he'd have shown dmesg output, it would clearly state so, but he did not. deprecated IDE driver are shown as hda, hdb etc. where as SATA and the same IDE disks with newer PATA driver are shown as sda, sdb etc. For you it is showing the disk as sda. Take a look at lspci -k to see which kernel driver is getting used. Also a very easy method to see the reading speed of the disk is You're talking about libata, the current all-in-one SATA/PATA/ATAPI driver. And yes, regardless of whether a drive is PATA or SATA, if it's under the control of libata, it will show up as /dev/sdx, or if it's a CD/DVD-ROM as /dev/srx. dd if=/dev/sda of=/dev/null bs=1M count=1024 This will read the first 1024MB of your disk. I think a good disk/controller gives you more than 70MB per second or so. That depends on many factors, the big one being whether the drive and controller both support NCQ, and if they both have a good implementation of it. Look at the ATA_NCQ_HORKAGE list to see a group of drives whose performance _drops_ considerably with NCQ enabled, or suffer other more serious problems with NCQ enabled such as filesystem corruption, data loss, etc. Other factors affecting sequential read performance (dd) are the elevator used, and the nr_requests and read_ahead_kb settings. Bumping read_ahead_kb up from the default 128 to 512 or 1024 will produce a decent increase in sequential read performance, about 10-20%. For example, a quick test on one of my lower end systems produces a 16% increase in sequential read performance: /$ dd if=/dev/sda of=/dev/null bs=1M count=1024 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 16.8026 s, 63.9 MB/s /$ echo 1024 read_ahead_kb /$ dd if=/dev/sda of=/dev/null bs=1M count=1024 1024+0 records in 1024+0 records out 1073741824 bytes (1.1 GB) copied, 14.4375 s, 74.4 MB/s (This system only has only 384MB RAM so little to none of the performance increase was due to buffers/cache from the first dd run) _But_ a high read_ahead_kb setting causes a huge rise in the size of kernel I/O buffers, eating system memory like candy. This one test caused a 6 fold increase in my kernel buffer size, to over 260MB. Playing with read_ahead_kb for testing can be useful in measuring absolute hardware performance, but I wouldn't run day-to-day with a setting much higher than the default. There are some specific server applications where high read_ahead_kb is useful, such as streaming media servers, but they are few and far between. -- Stan -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/4c2c23ff.7010...@hardwarefreak.com
