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Subject: Re: maximum MAXBSIZE
To: Wojciech Puchar <wojtek@puchar.net>, freebsd-hackers@freebsd.org
References: <alpine.BSF.2.20.2001072210410.21107@puchar.net>
From: Hans Petter Selasky <hps@selasky.org>
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Date: Tue, 7 Jan 2020 22:23:54 +0100
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On 2020-01-07 22:12, Wojciech Puchar wrote:
> default MAXBSIZE is 128kB. badly low for todays magnetic disks.
> 
> i have it set to 2MB on all computers that have magnetic disks. Great 
> improvement with large files. especially when more than one are 
> read/wrote in parallel. And no problems experienced
> 
> But for optimal performance MAXBSIZE should be transfered in few times 
> longer than average seek time. todays disk do 200-250MB/s so 2MB is 
> transfered below 10ms.
> 
> 8-16MB seems like good choice. is there any reason not to set it that high?

Old disk may not support it, especially USB 1.0/2.0 disks.

--HPS