From: Josh Gelinske <jgelinske@appareo.com>
To: u-boot@lists.denx.de
Subject: [U-Boot] [PATCH RFC] NAND: Improve read performance from Large Page NAND devices
Date: Fri, 15 Jan 2010 17:51:38 -0800 (PST) [thread overview]
Message-ID: <27186018.post@talk.nabble.com> (raw)
In-Reply-To: <4B1F8D70.5070105@ge.com>
What kind of CPU usage are you seeing? I am throughput of ~1.9MBs for writes
on a Samsung K9WBG08U1M 4GB with 4K page but with high cpu usage.
Nick Thompson-9 wrote:
>
> On 09/12/09 11:02, Wolfgang Denk wrote:
>> Dear Nick Thompson,
>>
>> In message <4B1E71D9.6080802@ge.com> you wrote:
>>> Improve read performance from Large Page NAND devices.
>>>
>>> This patch produces a ~31% improvement in oob_first read speed (on a
>>> 300MHz ARM9). The time for a mid-buffer 2k page read is now 293us,
>>> 6.99MB/s (was 385us, 5.31MB/s). oob_first is probably the best case
>>> improvement.
>>>
>>> Signed-off-by: Nick Thompson <nick.thompson@ge.com>
>>
>> Also tested on Canyonlands (460EX); here I actually see a slightj
>> improvement (5.5% faster, i. e. time to read 126 MB from NAND goes
>> down from 28.8 to 27.2 seconds (4.4 -> 4.6 MiB/s).
>>
>> Tested-by: Wolfgang Denk <wd@denx.de>
>
> Hi Wolfgang,
>
> Thanks again.
>
> It seems the raw page data transfer rate is quite low on that board.
> The patch saves time between page data transfers, so the percentage
> improvement seen is better if you can get the page data out quicker.
>
> The default read_buf (and write_buf) in nand_base.c are safe, but slow.
> I put in davinci specific optimised versions (DMA or multibyte read
> ticks might be used) to double my raw transfer rate. Without that, my
> measurements would show ~15% improvement only.
>
> In total on da830evm I'm getting a >300% speed improvement. 1.69MB/s
> changes to 6.99MB/s. (5.31MB/s without this patch.)
>
> Nick.
> _______________________________________________
> U-Boot mailing list
> U-Boot at lists.denx.de
> http://lists.denx.de/mailman/listinfo/u-boot
>
>
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Sent from the Uboot - Users mailing list archive at Nabble.com.
next prev parent reply other threads:[~2010-01-16 1:51 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-12-08 15:33 [U-Boot] [PATCH RFC] NAND: Improve read performance from Large Page NAND devices Nick Thompson
2009-12-08 22:06 ` Wolfgang Denk
2009-12-09 9:43 ` Nick Thompson
2009-12-09 11:02 ` Wolfgang Denk
2009-12-09 11:43 ` Nick Thompson
2010-01-16 1:51 ` Josh Gelinske [this message]
2010-01-18 12:48 ` Nick Thompson
2010-01-18 15:16 ` Josh Gelinske
-- strict thread matches above, loose matches on Subject: below --
2009-11-25 13:57 Nick Thompson
2009-12-01 0:55 ` Scott Wood
2009-12-01 10:13 ` Nick Thompson
2009-12-01 11:34 ` Nick Thompson
2009-12-01 18:43 ` Scott Wood
2009-12-01 18:38 ` Scott Wood
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