+1; I'm getting almost the same as the above on a SXCE99 box, Intel USB controllers + random usb pens.
Regards, Edward. 2008/11/17 <Casper.Dik at sun.com>: > > >>> I logged this bug: >>http://bugs.opensolaris.org/view_bug.do?bug_id=6720764 >> >>Ages ago. >> >>I just did the dd test with an 8 MB block size and obtained about 16 MB/sec, >>so this (apparently) confirms the problem is related to pcfs, though in the >>past I also had bad performance using UFS.... >> > > Specifically in USB or specifically on flash media? > > There are many different types of readers and types of media. > > E.g., I used to have a VIA EPIA (now broken) and its flash reader > worked at 12MB/s (it's on the motherboard, but still connected with > USB 2.0) > > I have 3 more CF card readers: > > white box: 5MB/s > Targus: 8MB/s > New Lexar: 17MB/s (and 27MB/s on a new UDMA card) > > (The other cards used are Sandisk Extreme III (older edition, no UDMA); > see also http://www.robgalbraith.com/bins/camera_multi_page.asp?cid=6007-9392 > > UFS on USB connected spinning media seems reasonable, but nowhere near > a direct connection (SATA/IDE). > > Flash media is different; and I'm not sure whether UFS does very well; > the amount of actual IOPS is important for flashmedia and UFS doesn't > know how to optimize. > > I'm not sure the kernel ordered IOPs send to flash media; the only thing > it should do is coalesce IOPs which would really help. > > When you have USB key, it's difficult to say how quick it would be (dd > is a fine tool, here). Cheap and/or older USB keys can be much worse, > especially when there are a lot of IOPs going on. > > Clearly there's a lot of things we need to do: particularly bringing > the number of IOPs down needed for a specific operation. > > Try reading from the same USB key using a 2K blocksize and compare > with the 16MB/s you get with 1MB blocksize. > > Casper > > > > _______________________________________________ > laptop-discuss mailing list > laptop-discuss at opensolaris.org > -- All Documents adhered to the ISO/IEC 26300 standard file format for electronic office documents, such as spreadsheets, charts, presentations and word processing documents from this email address. The author does not take responsibility of the recipients inability to read international standards and who use proprietary products such as MS Office. See: http://www.openoffice.org/ Edward O'Callaghan. -- http://fedoraproject.org/wiki/EdwardOcallaghan http://moonshine.opn4.org/ http://www.pcbsd.org/
