Transcend 8GB 266X CompactFlash Card

[legomanx51v]

mmm.

this is a bit annoying as i was thinking of buying a 133x 8gb card, and expecting it to be faster, and hopefully giving me speeds of about 4mb/sec. but it seems that it takes a 266x card to do that.

btw, the reason i wanted to know all this is because i wanted to ditch my 30GB ipod for my axim+8gb of storage. but the ipod transfers 1GB in 5 min, and i wanted a CF card that could match this. do you think a 133x CF can be as fast as that considering it took your 266x CF 275seconds?

[ComPH]

Yes, I think that you will be close to the same performance as with the iPod, with the reader and the 133x CF, and I'd guess that the CF will be little faster than saving data on the iPod's disk, and that the iTunes add some overhead to the iPod because there is a lot of checking, versus simple Copy and Paste you'd do in case of the CF and card reader. I think that the S/W represents the key overhead, so that if you spend say 10% of the time actually accessing the devices, 100% difference in the access speed of these devices will only result in 10/5% difference in the overall transfer time.

[legomanx51v]

That bit of news is music to my ears! (sorry, had to make the pun)

thank you very much for answering my questions, you have been very helpful.
also, i tried to offer a solution to your problem with needing more desktop space in your other thread.

[ComPH]

You are welcome. On the screen space, I think I'll try the S/W described at: http://www.saman-cz.com/ppc/index.html. He allows flexibility in the screen layout.

[ebv]

Well, I have an x51v and a 4GB SD 150x from Transcend, and with a no-name card reader, USB 2.0 of course, I got up to 9.9-10MB/sec. After getting a Transcend USB 2.0 reader, with the original cable, I got over 18-19MB/sec read/write speeds! I also got the same package - x51v + 4GB SD 150x - for a friend, and a couple of weeks ago I bought for him an 8 GB 133x CF Tanscend. I didn't test it yet with my card reader, but now I'm curious... and I'm very curious what will be the max speed for the 266x CF! I think I'll order one, just for that! :) I'll let you know how it works...
In the mean time... buy a card reader from Transcend! You'll be surprised how fast it is. I was...

[spud42]

As CMOS devices switch, they cause momentary high current draw on their power supplies, due to the fact that both transistors are momentarily on, de-facto shorting the power supply to ground. Secondarily, there is a higher current draw as the outputs drive the capacitance of the circuit traces and the inputs of the sink devices they drive into cause momentary current draw, until the level stabilizes. As there are many outputs switching almost randomly, especially when various delays due to impedances of lines become significant with respect to the clock frequencies, these spikes on the power supplies become basically a random noise. This noise is largely filtered by the decoupling capacitors, but as the devices become faster, the spikes can be of higher magnitude and shorter duration, so the decoupling capacitors will not be as effective cleaning this higher frequency/amplitude "noise". Since the noise is seen by the reference circuits of the receiving device, it then can either see erroneous input levels of signals or clocks and therefore the computer can behave erratically or even stop working, depending on the design tolerance, power supply or battery levels, temperature and the speed and noise tolerance of the receiving device, e.g. CPU, which would, for example, clock in the wrong data from the memory. This can happen when older technology platform gets new companion components and why I had the original question.

this may well be true of a poorly designed circuit. but as the cf slot is in fact a "bus" a well designed circuit would incorporate termination. either active or passive these circuits are designed to minimise or eliminate reflections in a transmission line scenario. also the speed that the memory is capable of isnt the issue it is the speed of the CF bus in the PDA its plugged into that determine the speed of transmission. you could have 500x speed CF card but if the PDA is only capable of 100x then that is the max speed the memory will operate at. buying faster memory wil not make it work faster unless the current memory speed is below that of the max transfer rate of the PDA.