Showing posts with label Compact Flash. Show all posts
Showing posts with label Compact Flash. Show all posts

Friday, 12 December 2008

Another Thing...

Beagle also bit the dust - it's not the performance maiming monster that Windows' background indexing is but I still don't need something chuntering away using power and generating extra flash writes in the background. It is noticeable on a 6-800MHz - grep does the trick for me when I need it.

Wednesday, 10 December 2008

U810 Flash

I now have the Transcend 32GB CF card as the main storage with OpenSuSE 11.0 on it - partitioned as 4GB root, 25GB /srv and 1GB swap (to allow suspend-to-disk). Install was relatively painless with the caveats already mentioned. Some things to note...

  1. I plan to use an internal sacrificial USB flash disk (with any luck!) ultimately for swap and tmp space to keep the write load on the CF card down.
  2. To simplify this I have created a tempfs for /tmp so temporary files are written to RAM and then swap - thus I only have to deal with moving swap to USB. To do this, add the following to /etc/fstab:

    none /tmp tmpfs size=1G,noatime 0 0
  3. Symlink /var/tmp and /usr/tmp to /tmp (technically this might be a little suspect in terms of security but this is a personal laptop, not a server)
  4. /var and /home might need some consideration as a whole but not right now
  5. Partitions are ext2 with noatime and noacl to help keep flash activity low
  6. As mentioned before, Transcend 133x CF seems to write at about the same speed as the Toshiba HDD and read around twice as fast. Certainly booting and return from hibernation are noticebly faster.
  7. Power consumption drops quite usefully with the CF card - with the HDD I never saw less than 7000mW (based on KPowersave readins). Now I've seen under 6000mW (with WiFi off) and nearly 6 hours runtime.
I've been rooting round under the bottom panel with a view to fixing an internal USB connector for my sacrificial scratch flash. armed with a multimeter it appears that the second PCI-E connector is not powered up - some fuses are missing but the adjacent power planes are also unpowered. There is, no doubt, something like a regulator that requires a pull up/down to get the power planes energised.

Anyway, looking around elsewhere doesn't turn up a lot of options for voltage sources (I am restricting myself to what I can reach under the bottom panel without further dismantling). I am considering using the SD card power supply voltage since the contacts are easy to reach and Fujitsu has opted for the uppoer end of the SD voltage spec and given it 3.5V.

3.5V should power 3.3V nominal electronics just fine. Many USB devices take the 5V supply and regulate it down to 3.3V immediately. I can either bypass the regulator and run the devices slightly over nominal or hope the regulator can cope with a voltage differential that small (possibly undervolting slightly). Now I just need some nice fine wire...

Friday, 7 November 2008

Transcend 32GB 133x

Preliminary tests with the card shows that Transcend have been very conservative with the speed rating of this card. The WRITE speed is 133x but the read speed is more like 300x. This works out at about twice the read speed of the Toshiba drive in the U810 - this is going to get interesting...

Friday, 31 October 2008

More on Compact Flash and the U810

OK, it seems that the ATA LIF connector on Toshiba drives (like the U810 has) are not entirely compatible with ATA ZIF connectors (like some iPods have). No idea why - but it makes a difference when looking for CF-ATA adapters.

The one I had before was ZIF and wouldn't work. I thought it was the CF Fixed/Removable problem but I was wrong. I saw other people with the U1010 - which, for whatever reason, uses a pin-style connector (very like compact flash) for at least some of its drives - have no problems with CF cards with Removable mode.

So, it must be the adapter and I need to find one that is Toshiba LIF rather than iPod ZIF. Another trawl around ebay nets me an alternative mode, the MW-CF18ZIFADP which is orange and only seems to come from Taiwan. I know it has ZIF in the name and says iPOD compatible but in very small letters it also says "compatible with Toshiba". I now have one and it works - with the additional benefit that it has a metal shell that make it exactly the same size as a Tosh drive and thus fits snugly in the U810 without rattling about.

The ZIF/LIF difference is subtle though - both work fine in my ICY-DOCK USB caddy for 1.8" drives, just not with the U810 ribbon cable - go figure!

Now, it's great to hear about all these 64GB and 100GB CF cards but, quite frankly, I'm not seeing any. Looks like the 133x Transcend is the one I can get. It's good for around 20 MB/s read/write which is not bad in comparision with the Tosh drives which are faster at peak but way slower when you get to the inner tracks. There are cheaper Adata and Peak 32Gb cards but these have a write spead of around 3 MB/s and read at 10 MB/s which is pretty glacial. Pretec have announced 266x and faster cards at this size but I've yet to see many for sale. I guess when you can charge 2-3 times as much for the same stuff in SSD format it's pretty obvious where the effort goes.

Friday, 8 August 2008

More U810 thoughts

The U810/U1010 has pads for two Mini PCI-e slots underneath the bottom cover but most only have one in place. Looking at the dissection photos on the Internet it seems that there are no chips or support components missing - just the socket - so it should be feasible to solder a new one in - the pads are easy to reach and the pitch isn't too small.

Getting said socket isn't too easy though - RS Components has them scheduled for October. It looks like the exploding demand for eee PC's and the like has drained the world's supply of Mini PCI-e sonnectors - later eee's also come with only one of two possible sockets in place.

The other alternative, in the same vein as many eee PC mods, is to tack a USB socket in place of the PCI-e connector (using the USB lines that are available on the PCI-e pads). That would be a nice place to put a USB key as an SSD or maybe a TV tuner... Now I just need to find a nice point I can source 5V from - with all the eee PC hacking out there I'm surprised there hasn't been a bit of U810 activity in this area.

I have also got a Compact Flash to 1.8" ZIF convertor (off ebay) to try out using CF as an SSD alternative - slower but actually designed for low power consumption so may well benefit run-time. The first couple of CF cards I tried weren't recognised by the BIOS. To test that it wasn't the convertor I got hold of an Icy Dock USB caddy from Scan - obviously designed for displaced iPod drives! The cards worked fine in this mode - I suspect it is because most CF cards claim to be removable ATA devices and some BIOS's will only accept fixed devices. Transcend is one of the few manufacturers whose CF cards switch to "Fixed" mode when operating in IDE, rather than CF, mode so I'll get hold of one and try it. Sandisk, Kingston and Intuix are brands which do not - from experience. Under Linux you can use hdparm -i on a CF card to find out if it is Fixed or Removable mode.

Elisa 5.3 seems to be an awkward release to get up and running - I had to edit the source code (to bypass a "not implemented yet" error) to even get the main screen up so I'll park that for now until a later release.