Ed Hudson wrote: > > the cost of soft updates, and the cost of hw.ata.wc=0 > > enclosed is a .jpeg of an xgraph of the following interactive test: [ ... ] > hw.ata.wc=0, soft-updates enables. > hw.ata.wc=0, soft-updates disabled. > hw.ata.wc=1, soft-updates disabled. > > the 'points' in the graph are the only real data (the lines > are xgraph's interpolations). A methodology comment... I'd like to see: hw.ata.wc=1, soft-updates enabled. Realize that it is the write caching, not the soft updates, which makes write caching dangerous... it's just as dangerous without soft updates, and mounted sync. The drive lies to us about whether or not the data was committed to stable storage, which is where the problem is coming from. Also, I can't tell if you are using sync or async mounts in the non-soft-updates case: I would suggest doing both. FWIW: I was just as annoyed when /dev/random went in, and shot embedded 386 performance all to hell... at least I actually get something from the write caching tradeoff. -- Terry To Unsubscribe: send mail to [EMAIL PROTECTED] with "unsubscribe freebsd-hackers" in the body of the message
- Re: general speed differences between 4.1.1-RELEASE and 4... Ed Hudson
- Re: general speed differences between 4.1.1-RELEASE ... Doug Barton
- Re: general speed differences between 4.1.1-RELE... Shannon Hendrix
- Re: general speed differences between 4.1.1-RELE... Mike Silbersack
- Re: general speed differences between 4.1.1-... Dominic Marks
- Re: general speed differences between 4.1.1-... Doug Barton
- Re: general speed differences between 4.1.1-RELEASE and 4... Terry Lambert
- Re: general speed differences between 4.1.1-RELEASE ... Ed Hudson
- Re: general speed differences between 4.1.1-RELE... David O'Brien
- Re: general speed differences between 4.1.1-RELE... Terry Lambert
- Re: general speed differences between 4.1.1-RELEASE ... Rik van Riel
- Re: general speed differences between 4.1.1-RELE... Ed Hudson
- Re: general speed differences between 4.1.1-RELE... Daniel C. Sobral
- Re: general speed differences between 4.1.1-... Rik van Riel
- Re: general speed differences between 4.1.1-RELEASE ... Mike Silbersack
- Re: general speed differences between 4.1.1-RELE... Terry Lambert
- Re: general speed differences between 4.1.1-... Kris Kennaway
- Re: general speed differences between 4.... Terry Lambert
- Re: general speed differences between 4.1.1-... Mike Silbersack
- Re: general speed differences between 4.... Terry Lambert