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Nikos Chantziaras wrote: |
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> On 01/22/2011 09:50 AM, Dale wrote: |
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>> Nikos Chantziaras wrote: |
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>>> On 01/22/2011 12:31 AM, Dale wrote: |
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>>>> [...] |
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>>>> And I thought there was something weird with me on this one. o_O I did |
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>>>> switch it back to AHCI after I got done booting the CD thingy. I |
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>>>> really |
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>>>> can't tell any difference in speed between the two and neither could |
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>>>> hdparm -tT either. |
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>>> |
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>>> hdparm measures raw throughput when reading continuously from one |
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>>> position to another. AHCI improves performance when the disk needs to |
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>>> read from several different places, which is the case in every day |
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>>> use. It does this by providing a feature similar to what SCSI |
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>>> provides: native command queuing (NCQ). You can read about what this |
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>>> is and why we want it here: |
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>>> |
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>>> http://en.wikipedia.org/wiki/Native_Command_Queuing |
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>> |
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>> Other than copying a file and using time to measure how long it takes, |
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>> what is the best test of a hard drive's speed? |
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> |
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> By running a benchmark tool that does exactly this. IOzone is a nice |
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> one: |
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> |
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> http://www.iozone.org |
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> |
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> It's in portage: "app-benchmarks/iozone". |
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I installed it but trying to figure out how to use it. Jeez, what a man |
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page. O_O |
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|
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> |
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> |
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>> Also, does or can the kernel override the BIOS setting? I think it uses |
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>> AHCI no matter what is in the BIOS. It seems it would be at least some |
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>> difference in speed. |
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> |
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> The kernel can't change this setting and has no access to it whatsoever. |
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> |
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|
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I didn't think so but thought it worth asking. Seems to be some |
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confusion on this. |
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|
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Dale |
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|
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:-) :-) |
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