benefit of Ultra/Extreme CF cards?

First post so Hello to everyone.
I spent several hours yesterday reading a lot of info about the CF and PC card slots on HPCs (720 specifically) here.
I came to the conclusion that there was no restriction to the memory size of a CF card though it might need formatting in the HPC before use first.

But I didn't find any info about whether the various Hi-Speed cards available now were of any benefit at all.
I would be very grateful is anyone could offer their observations or point me at a previous discussion if this subject has been covered recently. Also please correct me if my intention to buy a 2gb CF card (maybe fast type) will lead to failure.

Thanks

Hi... in my experience, there really is no appreciable difference in speed using these so called high speed cards. They might be a factor when you use them for photography, where you would need quick write times as you go for multiple shots, but on the whole, for our usage, don't make that much difference.

On the 720, I'd doubt there's enough power to make the difference noticable.

I've got a 2gb Kingston "pro" card, a 1gb generic card, a 512MB Sandisk and a 256MB Sandisk Ultra II card.

The 2GB kingston pro, which is branded as Jessops, is the best performer. The 512MB sandisk is slowest. in reality, they all work well on the 720.

I think that the 720's system bus also limits the speed of transfers anyways, so all cf cards should be about the same. (Except for those old 4x cards...)

I'm glad to hear that a 2gig CF will work on a Jornada. Hadn't ever actually seen that verified before.

Jake

of course it works...

The speed thingie ... there *is* a difference ... but not if you are just copying a single 5kb file. I occassionally would backup my data on the CF card to my notebook, and reformat the CF. When I copy the files back (some 400+mb) ... there is a very huge difference. But like I said, if its just a 5kb file ... you won't see much diff. 1000 X 5kb ... yes, you will see a diff.

That is from the cf to your notebook. I mean the cf speed on the H/PC, with its limited bus speed.

I find no difference in performance on my 6651/720 using cards from 4x to 80x. My hpcs top out about 200-250Kb when using a CF card. Perhaps a faster hpc like the S3 could benefit from a faster card, I dunno. Monica could answer that.

Anything under 32gig will work

As far as my opinion goes, on a 720 there is nothing to be gained, the bus speed is the liniting factor, and no matter what you do (short of writing a driver to use the write cache) nothing is going to change that.

Wallythacker could be correct however re CE .net devices, s the implementation differs. Quantitative benchmarking would be needed to prove or disprove that hypothesise mind.

My point I would of had, if I submitted it, but I only did a years worth of computer science and VB programming and didn't pass the course! :-(
The other limiting factor is what the CPU is tied up with (open tasks), the RAM speed, etc, etc, etc.
The problem is, that the data from the card to the CPU, has to go Card > PCMCIA/Card Controller > CPU > RAM > CPU > Destination (in this case, RAM for storage), I believe this is the fetch excute cycle and I must dig out my notes on that! :-)
All these processors (essetunally what they are, they process different parts of the PC) run at different speed and the buses that connect the processor/chips together run at different speeds, not really possible to "exploit" the fasters speed, as there will always be a bottle neck/limit somewhere!

The bottle neck is the speed of the Cf controller, which is only designed under the CF II specification to handle data through the databus at the staggering rate of 16 Meg a second.
As the devices offer no write combining, and there is no chance of DMA access (it's new on CF III) absolutely everything has to trouble the CPU with the data stream and the interrupts as well as the control registers and so on and so forth. With older devices you have the additional headache of the CPU bothering itself to keep a picture on the screen.

Ultimately as Windows CE has little in the way of caching facilities either going through the processor, the fastest operable speed is going to be that of the slowest component. Whether that is in fact the CPU, the IDE controller, the databus who knows.

May argument on these so called super charged CF cards has always been the fact that they are claiming to have CFII OK on the device, yet proport that their devices run a Yx10 to the 4 of the speed of the CFII specification. So to me it's like selling a car that apparently has warp drive, yet amazingly there is no control system for the warp drive, no obvious sign of the warp engine - but it's all good because the sales man said so.
Again I'll stress that WinCE does NOT use write combining.

i don't know, i don't have high speed cards... but the sig3 is certainly much faster with handling a SD card than the jornada.. CF seemed slower to me (than SD), but i didn't do benchmarks also it may have been a slow CF.

Strange CmoneX. SD is only 10Meg/second so by all rights it should be noticably slower

well there are a lot of fast SD cards nowadays. they're faster than the average CF.

but my SD isn't an ultra card or anything, that's for sure. i think it is around 1-2 MByte/s (read/write) for it on the sig3. i should benchmark it..