[lug] RH Linux download + hdparm

[John Karns]

On Fri, 19 Oct 2001, D. Stimits said:

> I forget how it is figured out, but a regular PCI bus is 33 MHz, not 33
> MB/sec. The bus is 4 bytes/octets wide (32 bit), so that means at least
> 4 * 33 = 132 MB/sec. In my case, I'm operating on a 66 MHz, 64 bit bus,
> so the minimum rate would be 4 times that. U160 is nice even on a
> regular 33 MHz PCI bus, but peak rates or the rate of a good raid
> controller could saturate the bus under normal PCI.

Thanx for the response.  But I'm not too sure about the gains.  I'm
running a U160 drive with an ultra-wide (40 MB/s Tekram 390U) controller
on an Asus P5A mobo (33 Mhz PCI, 500Mhz K6-II cpu).  hdparm says I'm
getting 15 MB/s.  I had been wanting to order a U160 controller to replace
the 390, but under the circomstances, I'm afraid that it could be a waste
of $$.  Perhaps I'll try a quick benchmark with an Adaptec 2940UW for
comparison to see if it's a controller issue.

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John Karns                                        jkarns at csd.net