Re: slowdown on Via ide chipsets with 2.4.15?

[Vojtech Pavlik <vojtech@suse.cz>]

On Thu, Nov 22, 2001 at 02:20:31PM -0500, safemode wrote:
> something i just took notice while fixing my computers.  
> hdparm -t to test the speed of drives, i have in the past had about 30MB/s 
> across all my drives.  
> Now, my primary disk, which is the only one on it's channel, gets 19MB/s 
> (udma2 speeds).  It's an udma4 drive and i've seen it get 30+ on average in 
> earlier kernels.  My primary master on the promise card gets 30+ still, but 
> my slave on the same channel gets 19MB/s even though the master is not being 
> used.  I know there is to be expected some performance drop, but that much is 
> a little disconcerting.  I have my atapi devices on the secondary channel of 
> my via controller (motherboard) and the second channel on the promise card 
> will be used for my new drive.  
> The harddrives are configured exactly the way they used to be and the kernel 
> is compiled with the exact same options for ide/dma and such.   The 
> changefile doesn't look like the via ide drivers were messed with.   The only 
> other difference is that all my drives are now ext3.
> 
> Controller (motherboard)  VP_IDE: VIA vt82c686a (rev 22) IDE UDMA66 
> controller on pci00:07.1
> Controller (card)  PDC20262: (U)DMA Burst Bit ENABLED Primary PCI Mode 
> Secondary PCI Mode.
> 
> All drives are set to UDMA4 (ATA66)    hdparm isn't used,  simple check shows 
> that everything is set the way it should be default.  
> 
> Also, the kernel displays UDMA(66)    wouldn't it be  ATA66.  UDMA comes in 
> 1,2,4, and 5.  that's like, ata16, ata33, ata66 and ata100.        

Send me your /proc/ide/via and hdparm -i /dev/hd*, and I'll see if I see
any problems there ...

-- 
Vojtech Pavlik
SuSE Labs