MiniSD card into RAM?

[pflatlyne]

Originally Posted by Shavkat

RAM's speed is 1000x more faster than PC's HDDs!
Now try to calculate how many times faster then your MicroSD

The fact is,Im not making this up or speculating. Your PC already does exactly that. Your PC uses virtual memory,which in essence makes your hard disk act like RAM. The reason this works is that memory references in a program tend to cluster together within a small region. The basic way this works is that you divide the memory into pages. As you run the program,the memory is accessed. If the program tries to access a page that is not in physical memory,then the page that is needed is loaded ,usually replacing a page that has not been used for awhile.

Consider it this way. Suppose your storage device can be accessed at a rate of 10MB per second(100ns per access). Now suppose your ram can be accessed at a rate of 1GB per second(1ns per access). Eveyrone here says,it wont work because your program would run 100 times slower. That is not true however. Suppose that your program makes 100,000 memory locations located near each other before it has to access a location in another page (100us). If the page is in memory,all is good. If that page is not in physical memory,then it must load the page from its storage device. Lets say a page is 1k. It takes about a 100 microseconds to load the page. Therefore there is an extra 100us added to the time for 100,000 memory accesses. Since takes about 100us to access 100,000 memory locations from physical memory,the effective time to access 100,000 memory locations is 200us. Therefore even though the storage device is 10x slower,the effective speed of the virtual memory system is only half as slow as physical memory. In effect,your 10MB/sec storage device acts like 500MB/s memory.

The real question here,is how many page misses will you get. If there are too many,things dont work well at all. This depends on the kind of programs that you are running,and also on how much real memory and virtual memory you have. (You cant push it to far,or things get really slow) It is known that in most applications this system works very well and in fact,most modern operating systems do this. (Windows,OS X, Linux,Solaris)

On an interesting side note,this is also how cache memory in your cpu works. Instead of a hard disk and a DDR-2 ram, you have very fast on die memory,and somewhat slower DDR-2 ram. Effectivly,the DDR-2 ram can run close to the 3Ghz speed of the cpu instead of the 800mhz speed of the ram. You of course take something of a performance hit,but its not that bad.

[snake0721]

I honestly do not see how people are all for a phone using flash memory, which is going to be writing, reading and deleting all the time no matter what, but are completely dissinterested against a memory card doing this to make the device run a bit faster.

I agree on the hypocracy of "I'll flash the ROM a million time, but I will NEVER use a SD card for RAM cause it will ruin the card"

It's replaceable y'all.

On terms of speed, I don't know the depth of such devices. So I can't argue much there.

Am I the only one who is willing to blow a few bucks every few months to replace an SD card? besides, I'll get a better phone eventually anyway, which I suspect most of you would be doing as well, I hardly doubt you will be investing in a PPC6800 for years to come.

[vesty16277]

Maybe this is a stupid question.What is the difference in the memory used in a PPC6600 that allowed you to use the slider bar to adjust the memory manually from storage to program and the moguls memory? I think thats what most of us are looking for.

[gator2k83]

On previous devices i think early wm5 and wm2003 the devices did not have actual flash memory but just a large chunk of ram that you could adjust for more ram or more storage. Hence the storage was just allocated ram that you could store files on. And if i am not mistaken the device had to have some sort of backup power in case your battery died you would not loose your data on the storage part. As ram can not save data once power is lost. The Rom and Ram on the Mogul is 2 separate chips one is actual RAM and one is flash memory chip.

[Shavkat]

If it was possible, many programmers had created this app!
Yes, it is possible to create app that can move all your tasks from RAM to MicroSD!
But it's impossible to work in device like that!
Any task from MicroSD wont work or work extremely slow!
If it was possible, believe me, HTC or others just REMOVED or REPLACED with cheaper and smaller RAM chip on their device, to make more profit!
It will be possible when our 400Mhg goes up to 1Ghz!
If your heard news, Samsung going to present and produce new 600Mgh chip!
If it will be, we don't need "3D Video Adapter"s like Nokia N95 or N82!
Our main chip will do it for US!

[pflatlyne]

Originally Posted by Shavkat

If it was possible, many programmers had created this app!
Yes, it is possible to create app that can move all your tasks from RAM to MicroSD!
But it's impossible to work in device like that!
Any task from MicroSD wont work or work extremely slow!
If it was possible, believe me, HTC or others just REMOVED or REPLACED with cheaper and smaller RAM chip on their device, to make more profit!
It will be possible when our 400Mhg goes up to 1Ghz!
If your heard news, Samsung going to present and produce new 600Mgh chip!
If it will be, we don't need "3D Video Adapter"s like Nokia N95 or N82!
Our main chip will do it for US!

If it was possible to use your flash memory stick to cache your page file in windows 2000,they would have done it. Must not have been possible. If it were possible in windows XP,they would have done it,must not have been possible. Yet NT,2000,XP,and Vista are all basically successively more refined versions of the same OS. The fact is,it WAS possible with 2000,they just didnt do it. The argument that anything you can possibly think of that is not done,must not be possible is just absurd.

It may well be that it would take more detailed knowledge of the WM os to make this work than is publicly available,but the fact is,it almost certainly IS possible. It may also be that the SD card reader on the mogul is too slow. It may also be possible that it is not. We dont really know that. (yes,reading from the sd card is slow on the mogul over the USB cable,but so is reading from internal storage,so that really tells us nothing)

I see one really good reason why MS does not do this in WM. With readyboost,they took care to make certain that removing the flash device would not leave the system unstable by keep a copy of the real swap file. On the mogul,you would lose the ability to swap the card out. If you did,you would leave the phone unstable,or hang it up completely. Those of us that want to use the card as swap space understand that. If you had the card setup like that,you just would know enough not to remove it. On the other hand,non technical type users might not understand that. All they would see is that if they removed their cards,the phone hangs,which would leave a very bad taste in their mouths. (Think of people like my gf,who cant even figure out how to pair her blackberry with her bt headset) These users are probobally 95% of their market so the phones are made for them.

The question isnt if its possible,its if the SD card reader hardware is fast enough,which it probobally is,and whether enough information can be found or figured out to create the software that can do this.

[gbm85]

You guys are misunderstanding how the page file works on Windows. WINDOWS DOES NOT USE THE PAGE FILE / READYBOOST AS MORE RAM!! It takes unused memory (i.e. from programs that are not currently being used) and writes it out to disk. While this would certainly be possible on a PDA, it would be pointless. It would take longer to write out unused memory to a flash card than it would to just close the program (which Windows Mobile currently does) and then open it back up when you need it again.

[arparent]

The only real obstacle I can forsee if this were possible is... what would happen if you ejected the card?

[Shavkat]

Originally Posted by arparent

The only real obstacle I can forsee if this were possible is... what would happen if you ejected the card?

BLOW!
Can make "HARDWARE" to smoke!

[one80oneday]

Well with eBoostr they made it possible for windows xp to use a flash drive as RAM so I would think it could be possible
http://www.eboostr.com/