Date: Mon, 25 Oct 2004 19:59:46 +0200 From: =?ISO-8859-1?Q?S=F8ren_Schmidt?= <sos@DeepCore.dk> To: Thomas.Sparrevohn@btinternet.com Cc: freebsd-current@freebsd.org Subject: Re: FreeBSD 5.3b7and poor ata performance Message-ID: <417D3F12.20302@DeepCore.dk> In-Reply-To: <200410251837.58257.Thomas.Sparrevohn@btinternet.com> References: <14479.1098695558@critter.freebsd.dk> <417D25E8.6080804@ng.fadesa.es> <200410251928.01536.victor@alf.dyndns.ws> <200410251837.58257.Thomas.Sparrevohn@btinternet.com>
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Thomas Sparrevohn wrote: > On Monday 25 October 2004 18:28, Victor Balada Diaz wrote: >=20 >>On Monday 25 October 2004 18:12, fandino wrote: >> >>>Thanks to the excelent job of Thomas Sparrevohn I get 52MB/s, this is >>>an excerpt of their comments: >>> >>>"Changes the DMA speed to 66 - The Controller is a 100 controller and = the >>>disks are 100 Disks but I think the default for the controller is 66 a= nd >>>hence there are most likely a small initialisation difference between >>>Linux, NetBSD and FreeBSD" >> >>Hi >> >>please can you post how do you solved the problem? >=20 > atacontrol mode <channel> DMA4 DMA4 > atacontrol mode <channel2> DMA4 DMA4 >=20 > The reason is that the motherboard only supports ATA100 on two out of f= our IDE=20 > channels and hence you need to force the two other channels to run at D= MA66=20 How do you come to that conclusion ? There is no such limitation AFAIK. However you can only get a total sum of 133MB/s divided by number of=20 disks (and minus some overhead on older system there is typically=20 110MB/s effective bandwidth).. The real explanation is much more likely that the timing specs are=20 marginal (overclocked ?) for the disks, which causes problems.. --=20 -S=F8ren
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