Flash Memory Speed Tests

in ,

I did some more speed tests on various SD cards and USB flash drives I had lying around.  These aren't extensive benchmarks, I don't really have the patience (or interest) to devote much more effort to this than I already have.  These were just quick "hdparm - t" tests and then I dumped the output to a text file.  I did each test 3 times and took the average. [table id=2 /]

Overall the Microcenter products did better than I would have expected.  I was surprised how poorly my Sandisk ExtremePro UHS-1 SD card did but I suspect that is more an issue of compatibility of the newer standards with the EeePC card reader than the actual card.  I was also surprised to see that, in general, USB flash drives outperform SD cards.  If the Raspberry Pi results are similar then I think it will definitely pay to put the swap space and any other disk intensive things on a USB flash drive rather than the SD card.

raspbmc.com is live

in

Raspbmc is a custom linux distro for use with XBMC on the Raspberry Pi that I've mentioned before but the website wasn't live at the time.  Here are the highlights from their site:

  • Custom Linux distribution with minimalised kernel.
  • Auto-updating
  • UI installers for Windows, Linux and Mac OS X to allow installation onto a removable device
  • PVR / AirTunes / AirPlay / Spotify integration
  • Same stability and support as the Crystalbuntu Linux distribution
  • Expansive capabilities allowing the installation of a desktop and web browser
  • AFP, NFS and SMB file sharing
  • Configuration utility allowing installation of custom nightlies, audio configuration, update management,
  • Server mode – allows MySQL database hosting and Thumbnail sharing for XBMC multiseat systems.
  • 1080p decoding
  • Free!

Micro Center Class 10 SD cards

in ,

I was at Micro Center today and decided to pick up a couple SD cards to use for my Raspberry Pi (when and if I ever manage to get one).  They've always carried house brand/bulk USB flash drives and SD cards for pretty cheap.  I've bought a bunch of the them over the years and, while they work fine, they always seemed pretty slow.  I was thinking I would get a name-brand high speed SD card for the RPi but then I noticed they carry an "Extreme Speed" house model so I decided to check one out. 

kevin@minteee ~ $ sudo hdparm -t /dev/sda
/dev/sda:
Timing buffered disk reads: 88 MB in 3.00 seconds = 29.31 MB/sec
kevin@minteee ~ $ sudo hdparm -t /dev/sdb
/dev/sdb:
Timing buffered disk reads: 46 MB in 3.11 seconds = 14.78 MB/sec

/dev/sda is the internal SSD on my EeePC 701 and /dev/sdb is the 8GB Micro Center card I bought.  It seems to be about half the speed of the SSD on reads which seems like it's pretty good.  I don't really have anything to compare it to at the moment though.

Raspberry Pi Lego Cases

in

Here are a few random links with information about Raspberry Pi cases.

Using the lego case model above as a starting point, along with the measurements from the other links, I'm going to try to work up my own Lego case.

SSH Compression

in ,

I still haven't gotten around to testing Dropbear but I did find that SSH has built-in compression that can improve performance over slow links.  So using the command: 

ssh -X -C user@host

Creates an X tunnel with compression which is much more usable for me.  It's still a bit slow but it is slow even on my LAN.  I'm still planning to see if Dropbear can squeeze a little more performance out of my old netbook.  Ultimately I don't think the Raspberry Pi will be much more powerful (if at all) than my netbook so every bit of performace optimization will help.

Dropbear SSH

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I don't really know what, if anything I'm going to do with this blog.  Probably nothing.  But for now, I'm going to use it as a public place to dump things that are interesting to me. For example I've been looking forward to the upcoming release of the Raspberry Pi.  I dug out my old Eee PC 701 netbook to start working on a few of my ideas for these little things.  I'm not sure performance-wise how they compare but the netbook is really feeling slow these days.  I just tried running firefox on it from work via SSH X forwarding and it was pretty much unusable.  I'm sure my home uplink speed is part of the issue but it seems like 1.5Mps should be adequate.  It's faster from a local LAN connection but still not great. Which brings me to the inspiration for this post.  I just stumbled across Dropbear on the rpi forums.  It's supposed to be a less resource intensive than OpenSSH.  I'll give it a try on the eeepc and if there is a noticeable difference I'll be sure to use it on the rpi.