Date: Mon, 3 Dec 2001 11:58:13 +0100 (CET) From: Søren Schmidt <sos@freebsd.dk> To: nuzrin@goose.net.my Cc: Miklos Niedermayer <mico@bsd.hu>, Greg Lehey <grog@FreeBSD.ORG>, current@FreeBSD.ORG Subject: Re: HEADSUP ATA support for newer SiS chipsets added Message-ID: <200112031058.fB3AwDT04544@freebsd.dk> In-Reply-To: <3C0CA5A6.6050003@yahoo.com>
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It seems nuzrin yaapar wrote: > > Hmm, yes that looks somewhat on the low side... > > Well, two things, the older VIA chips are not the best performers, but > > I still think it should be better than that, I'll run some tests here, > > I might have messed up something... > > Are we talking -current or -stable here ? > > > > -Søren > > > dmesg: > atapci0: <VIA 82C686 ATA100 controller> port 0xd000-0xd00f at device 7.1 > on pci0 > ad0: 12416MB <QUANTUM FIREBALL CX13.0A> [25228/16/63] at ata0-master UDMA66 > > output: > 1+0 records in > 1+0 records out > 524288 bytes transferred in 0.023098 secs (22698423 bytes/sec) Hmm, I've just played around a bit, it seems we are hit by interrupt latency or something, if you limit the transfer to 128k, which allows the ATA controller to fetch it in one go, you will see the expected transfer rates. Now I dont see this on PCI based controllers, and that hints that the problem could be the fact that the two onboard controllers sits on irq 14 & 15 making them the lowest priority devices in the system, and that could cause the interrupt latency I'm seeing which then again causes the bad transfer rates on transfers that need to transfer more that one transaction full of data (ie max 128k). -Søren To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
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