linux-kernel - Speed of SDHCI subsystem

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 19 May 2009 00:37:50 +0200
From:	"J.A. Magallón" <jamagallon@....com>
To:	LKML <linux-kernel@...r.kernel.org>
Subject: Speed of SDHCI subsystem

Hi all...

I have notice something strange with SD cards.
I have an Aspire One and had an 8Gb SDHC card that used for my home,
and have recently upgraded to a 16Gb one.
This new one came with an USB reader.

The thing is that cards look much faster when accessed through the USB
key that directly on the readers of the One.

Some numbers with hdparm:

TakeMS 8Gb Class 6:
	Gives 10MB/s on the slot, 17MB/s via the USB key
SanDisk UltraII 16Gb, Class 4, advertised as 15Mb/s:
	Gives 10MB/s on the slot, 14MB/s on USB

I know that hdparm is not a benchmark, but I supposed it should be
limited by the media, not the connection.

But somehow the SDHCI/MMC subsystem seems to be stuck at 10MB/s, independent
of the quality of the media.

Any ideas ?

-- 
J.A. Magallon <jamagallon()ono!com>     \               Software is like sex:
                                         \         It's better when it's free
Mandriva Linux release 2010.0 (Cooker) for x86_64
Linux 2.6.29.2-desktop-1mnb (gcc 4.3.2 (GCC) #1 Wed May
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/