Date: Mon, 7 Feb 2000 12:08:02 +1030 From: Greg Lehey <grog@lemis.com> To: Rowan Crowe <rowan@sensation.net.au> Cc: freebsd-isp@FreeBSD.ORG Subject: Re: Performance of FreeBSD and MS Windows. What about select() and memory management etc ? Message-ID: <20000207120802.K22697@freebie.lemis.com> In-Reply-To: <Pine.BSF.4.01.10002071224470.23293-100000@velvet.sensation.net.au> References: <20000207114238.G22697@freebie.lemis.com> <Pine.BSF.4.01.10002071224470.23293-100000@velvet.sensation.net.au>
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On Monday, 7 February 2000 at 12:29:54 +1100, Rowan Crowe wrote: > On Mon, 7 Feb 2000, Greg Lehey wrote: > >> On Monday, 7 February 2000 at 11:40:43 +1100, Stanley Hopcroft wrote: > > [...] > >> Getting back to your own experience: by default, FreeBSD doesn't do >> DMA on IDE drives. It's possible that the perceived performance would >> be much better with DMA. In addition, kde is a known memory hog. > > Do you know of any pointers to increasing the performance (in general) of > FreeBSD's IDE drivers by tweaking the kernel settings? There's not too much else you can do, apart from setting DMA and maximum transfer length. Note that the current driver is going away. Even the upcoming 4.0 release will have the new driver, at, which should be a lot better. In particular, there's a known problem with the wd (old) driver with partitions over 27 GB in size. These *must* be run in LBA mode. See wd(4) for more details. > A related story: > > I have a 1Gb drive which came to me marked "faulty", but I ended up > putting it into a FreeBSD machine and it has worked flawlessly for the > last 18 months. I recently put it into a Win95 machine and it's been > gradually corrupted to the point where the file system is almost unusable. > If I only used Windows I'd probably also be considering it faulty. > > I'm guessing it's because FreeBSD is more conservative (by default) with > IDE settings/features so it's being more gentle on the drive. Windows is > trying to automagically milk every last bit of performance out of it so > that's why it is failing. That's one possibility. It's also very possible that, if you ran DMA on it, you might end up with the same kind of problem. While testing the new at driver, we discovered that it would refuse to run DMA on a number of drives which the wd driver accepted quite happily. We're still not completely sure that this isn't a problem with the new driver, but what we've seen points towards problems with the drives themselves. Greg -- Finger grog@lemis.com for PGP public key See complete headers for address and phone numbers To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-isp" in the body of the message
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