why does UATA/133 == UATA/100 on amd64?

[fbsdmail at dnswatch.com]

On Fri, June 4, 2010 10:58 pm, Alexander Motin wrote:
> Peter Jeremy wrote:
>
>> On 2010-Jun-04 16:36:08 -0700, fbsdmail at dnswatch.com wrote:
>>
>>> After _finally_ making the correct decisions to install amd64 on an
>>> AMD64 system. I was able to make/build/install world && kernel, I see
>>> a difference in drive recognition.
>>
>> Can you please do a verbose boot and post the resultant dmesg somewhere
>>  (preferably with your USB DVD drive connected).
>>
>>
>>> kernel: ata3-master: pio=PIO4 wdma=WDMA2 udma=UDMA133 cable=40 wire
>>> kernel: ad6: 476940MB <Seagate ST3500630AS 3.AAK> at ata3-master
>>> SATA300
>>>
>>
>>> kernel: ata3-master: pio=PIO4 wdma=WDMA2 udma=UDMA133 cable=40 wire
>>> kernel: ad6: setting UDMA100
>>> kernel: ad6: 476940MB <Seagate ST3500630AS 3.AAK> at ata3-master
>>> UDMA100
>>> SATA 3Gb/s
>>>
>>
>> The 'UDMA' numbers are meaningless for SATA controllers/drives.
>>
>
> The 'UDMA' numbers are meaningless for _native_ SATA controllers/drives.
>
>
> They may be not meaningless for legacy SATA devices, using SATA->PATA
> bridge inside. Some bridges do not support UDMA133 on PATA part, so ata(4)
> prefers not to use it. But in this case it is indeed meaningless.

If it's not already apparent. The board has an AMD 880G chipset, that
provides RAID support on 6 ports @ 6GBs. Now, from a purely logistical
standpoint. The numbers _can't_ be meaningless. It's clear that the kernel
is making a "judgment call" here: kernel: ad6: setting UDMA100

The "judgment call" on both GENERIC/i386, and GENERIC/amd64 was never
made. The capability of both the port && the drive were accepted. Both
cases were booted using "verbose" (5). Please understand, I'm not
attempting to be argumentative here. I just observe this to be true.
In other words; it must have _some_ meaning - no?

Thanks for taking the time to respond, Alexander.

--Chris

>
> --
> Alexander Motin
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>


-- 
kern:
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MB:
MSI 880GMA-E45 (socket: AM3)
CPU:
AMD Phenom X3 440 (3 core) @3.5Ghz
RAM:
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