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albright
Advocate
Joined: 16 Nov 2003
Posts: 2588
Location: Near Toronto
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 Posted: Sat Mar 10, 2007 2:07 pm Post subject: new motherboard slowed hard drives ?! (SOLVED LOL) |
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I had a motherboard fail and replaced it (asus A8V-SE) with
a new one (asus A8N-SLI-SE).
Everything else is exactly as it was - of course I had to recompile
the kernel replacing via options with nvidia/nforce options.
I noticed something odd; here is the hdparm -tT report:
| Code: | /dev/sda:
Timing cached reads: 1732 MB in 2.00 seconds = 866.59 MB/sec
Timing buffered disk reads: 204 MB in 3.00 seconds = 67.94 MB/sec
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With the old via chip motherboard, the cached reads were about 1200.
The disk reads are the same (naturally, since the disk drive hasn't
changed).
It is mortifying that my centrino 1.1 ghz laptop gets a better cached read
result than my amdx2 3800+ 
I wonder if there is some kernel option I might have missed. (But I
tried the "generic" x86_64 kernel from the install disk which loads
*everything* and got the same hdparm results.) Maybe I have
discovered that the via chipset just is better than the nforce chipset
(at least of the A8N/V vintage). BTW, in both cases, the bios settings
were at default (all timings set "automatically") so I guess it is also
possible that the A8N settings are more "conservative" ...
Any advice would be very welcome. TIA
Last edited by albright on Sun Mar 11, 2007 1:51 pm; edited 1 time in total |
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PaulBredbury
Watchman
Joined: 14 Jul 2005
Posts: 7310
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| Posted: Sat Mar 10, 2007 2:24 pm Post subject: |
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| Check what your BIOS says about the RAM speed, especially if it's DDR-capable/enabled. My mobo needs the RAM in specific slots, for DDR to be enabled. |
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albright
Advocate
Joined: 16 Nov 2003
Posts: 2588
Location: Near Toronto
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| Posted: Sat Mar 10, 2007 5:19 pm Post subject: |
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| Quote: | | Check what your BIOS says about the RAM speed, especially if it's DDR-capable/enabled. My mobo needs the RAM in specific slots, for DDR to be enabled. |
OK, that's a good idea. In fact, the manual for the new motherboard
says that if using just 2 sticks the memory must be in slots 1 and 3.
And they weren't (in slots 2 and 4). But after moving them there is
no change in the hdparm result.
The bios reports memory at 400mhz so that seems right. Just for
fun I increased the memory to 500mhz (which it could easily take
since its ddr4000). The hdparm cached reads went up to about
1000. Still not nearly as good as it used to be.
Is it possible that this memory is somehow incompatible with the
board and is not running in "double data rate" mode??? How would
I know? (too bad I don't have some extra memory laying around,
but I don't). |
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PaulBredbury
Watchman
Joined: 14 Jul 2005
Posts: 7310
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| Posted: Sat Mar 10, 2007 7:29 pm Post subject: |
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| My BIOS shows the RAM speed and DDR at boot up (only shows for about 5 seconds though). |
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albright
Advocate
Joined: 16 Nov 2003
Posts: 2588
Location: Near Toronto
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| Posted: Sun Mar 11, 2007 2:41 am Post subject: |
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Here's an interesting additional fact:
I booted both knoppix (32 bit) and the gentoo live cd (64 bit).
In both, the "cached reads" went up to about 1900MB/sec.
So I think there *must* be something misconfigured in all my
kernels (including - mysteriously - the generic kernel that
was generated when I first installed). These kernels range from
2.6.17 to 2.6.19 ... |
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albright
Advocate
Joined: 16 Nov 2003
Posts: 2588
Location: Near Toronto
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| Posted: Sun Mar 11, 2007 1:56 pm Post subject: |
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On another computer I updated hdparm and suddenly the
cached reads dropped in half.
Finally, I looked at the hdparm webpage only to see:
| Quote: | | The (over)reporting of "-T" results was fixed. |
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Kernel & Hardware
