Re: 2.6.0 performance problems

[Thomas Molina <tmolina@cablespeed.com>]

On Tue, 30 Dec 2003, Martin Schlemmer wrote:

> > It's not uncommon for a laptop to have a hard disk which supports
> > higher DMA modes than what the IDE chipset supports.
> > My aging Intel 440BX based VAIO has a disk in the same configuration
> > as yours, supports udma4, but chipset only goes up to udma2.
> > 
> 
> Right, or as somebody else pointed out, it might not be a 80-pin cable.
> 
> Lets rephrase - does it also run in udma2 mode with 2.4 ?  And did
> you check readahead?  In 2.6 it seems that a bigger value is better -
> I for instance have to set it to 8192 to have the same performance as
> in 2.4 ...

8192 will be my next test.  I'm doing a compile at the moment.  It runs in 
udma2 under both 2.4 and 2.6.  If I need an 80-pin cable then udma4 is not 
possible for this system.  If I read the following, it is only capable of 
66MHz anyway:

00:07.1 IDE interface: VIA Technologies, Inc. 
VT82C586A/B/VT82C686/A/B/VT8233/A/C/VT8235 PIPC Bus Master IDE (rev 10) 
(prog-if 8a [Master SecP PriP])
        Control: I/O+ Mem- BusMaster+ SpecCycle- MemWINV- VGASnoop- 
ParErr- Stepping- SERR- FastB2B-
        Status: Cap+ 66Mhz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- 
<TAbort- <MAbort- >SERR- <PERR-
        Latency: 64
        Region 4: I/O ports at 1420 [size=16]
        Capabilities: [c0] Power Management version 2
                Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA 
PME(D0-,D1-,D2-,D3hot-,D3cold-)
                Status: D0 PME-Enable- DSel=0 DScale=0 PME-