Slapping in another DRAM slot on a desktop is easier than on a notebook. DRAM is cheaper than NAND flash. If you're just going to be using it for a cache, then on a desktop, RAM is the way to go.
Yes, but Ram drives are not convenient and just adding ram will not give you the same effect. You can install just about anything to a ram drive, even operating systems, but as soon as you reboot, you have to install everything all over again. I dont know if people still do it, but it used to be fairly common among hardcore PC users to install GLQuake to a ram drive for better frame rates, benchmarks ect... It seems to me like a few years ago there was talk of creating ram drives that would remain powered up even when the PC (we are talking PCs here) were turned off. I don't know what ever became of that idea. My guess is one of two things; either the drives were to volatile and easily corrupted, or the cost was too high for any real market viability. There are raid controllers that allow for copious amounts of ram installed directly on the controller board itself though.
Slapping in another DRAM slot on a desktop is easier than on a notebook. DRAM is cheaper than NAND flash. If you're just going to be using it for a cache, then on a desktop, RAM is the way to go.
Flash is so where it's at, only not quite today.* I'm totally getting a 16gb compact flash card to put in an IDE adapter for my PowerBook, whose hard drive has seen better days anyway.* Currently there's just not enough capacity in flash, but 16 gigs should handle Tiger / Leopard and my apps with some room for swap.* FireWire for the rest.* I'm a finnicky bugger for silence and fancy the experiment.* I dub thee "FlashBook".
Um but yes, the extended hard drive buffer idea of Intel's is sound.* The platforms for future generations of MacBook±Pro should be pretty interesting.
You don't want to swap with flash, that's what's going to kill it with limited write cycles unless the OS regularly moves the swap file location every time it writes, but if you have limited space, that wears it out much quicker. You'll want to max out the RAM to minimize swapping.
My Application directory is 9GB. I suppose I can cull it of lesser-used programs, but it's not going to carry a lot of media or working files for portable use.
I really don't have a noisy notebook drive (I can't even hear it clicking), so the reduced noise is not much benefit to me. Most of the faint noise that my notebook makes is the fan for cooling the hot CPU.
The use of flash memory as cache doesn't make a lot of sense. Its use as a replacement for rotating disk platters sounds good until you do a little math. It is the technology of the future and probably always will be. Compared to conventional hard drives, flash memory is very expensive and very slow. Then there is the issue of read/write cycles. Virtual memory OSes access the hard drive a lot. When will the flash memory be able to handle the read/write cycles required of MacOS X?
What type do USB pocket flash drives use? Those things can fit 4GB in a package the size of a small pack of gum and only cost $100. I have a hard time finding 1GB RAM sticks for much less than $100.
Yes, but Ram drives are not convenient and just adding ram will not give you the same effect. You can install just about anything to a ram drive, even operating systems, but as soon as you reboot, you have to install everything all over again.
Quote:
Originally Posted by demenas
RAM would require battery backup.
Steve
Yes, which is why I said specifically...
Quote:
If you're just going to be using it for a cache,
... to qualify it if it being used for cache only. Obviously it has other applicability for persistent storage.
Yeah that, and with Nand there's a limited amount of times you can read/write to it.
/but they're working on that.
Yeah, I was going to post that as well. I haven't heard much talk about that aspect.
One can write about 100 thousand times to this, but can read more than a million times.
So, while I can see this used for information that won't be changed much, there are newer technologirs for FLASH that will be out that will solve the write problem.
Without that being solved, there is no way that it could be used for a HD replacement.
The math has been done for this *many* times. According to *their* math, it should last for quite some time. Much longer than you will probably retain the notebook. So I wouldn't worry too much.
100 thousand writes can be completed in a few months.
I think that this is a great item for Microsoft, since they have to reboot so often. For me, I reboot when a new security fix requires it. Otherwise, my iBook (my MBP arrives tomorrow) just shuttles from home to work with the lid closed.
Perhaps I am missing a key value to this. Anyone else think that improving the boot time of a MB or MBP is not much of an issue for OSX users? Perhaps Bootcamp users want this!
Well regarding MS, I thought I saw a demo of a laptop running Vista where Vista allowed pda-like operations to take place in a small window on the lid of the laptop. This ran some palm-like apps that could be accessible without even having to open or awaken the computer itself.
I have thought for a while that Apple should be making their laptops more instant on, but they don't need to do it for everything. I don't care that Photoshop takes 5 minutes to load b/c after I start it up, I keep it going for quite a while and over the course of the day the boot time is insignificant. However the fact that iCal takes almost as long to load as Photoshop is exxasperating!!! I want to know within 5 seconds whether I'm late or not.
I think Apple's productivity iApps are perfect to be sitting in a NAND memory buffer so that iCal, AddressBook, Mail, Stickies and Widgets are absolutely available with no waiting. That would make the OS as a whole seem instantaneous. Who cares if Illustrator takes a while, it is an excuse to get another coffee.
I'm genuinely curious; please find me a source that states that NAND flash read cycles are limited.
This is one. I'll quote from it, as well as give the link, as it's a long scroll 'till you get to this. It's interesting though, so you might want to read the whole thing. Where he says 1m read/writes, he really means 1m reads.
"But besides cost, there are other obstacles for Flash memory replacing hard drives. Flash memory is typically guaranteed for around 1m read/write cycles, which sounds a lot, but in the context of the working life of a PC (which is continually writing, erasing or rewriting data) is not. So designers have to use techniques known as wear-levelling to shift data around the Flash memory block to reduce the risk of data error. "We can design around the problem," says Walsh."
Wiki has this, which is, surprisingly correct, but as usual, not totally complete. Look down to where it says EPROM etc. lifetime.
The write life is complete. The read life is correct as far as it goes, in that they do say that it is limited, but they don't say that that limitation is considered to be about 1 million cycles. It isn't cycle limited, it's true, but the charge leakage gets worse with time, just as it does in most capacitors, and that charge drop ends up in a life limitation which usually comes out to 1 million cycles.
I don't think a random newspaper that doesn't even focus on technology is a particularly good source. As for Wikipedia, it is self-contradictory, as it also states:
Quote:
When compared to a hard disk drive, a further limitation is the fact that flash memory has a finite number of erase-write cycles (most commercially available flash products are guaranteed to withstand 1 million programming cycles) so that care has to be taken when moving hard-drive based applications, such as operating systems, to flash-memory based devices such as CompactFlash.
This implies that the limitation only applies to write cycles.
I don't think a random newspaper that doesn't even focus on technology is a particularly good source. As for Wikipedia, it is self-contradictory, as it also states:
This implies that the limitation only applies to write cycles.
There are quite a few other sources.
You can go and look if you want to see this that badly. They all say about the same thing.
In fact, most Flash cards have only about 10,000 write cycles.
Most information is concerned with writes, because it is so poor.
Leveling does help. But mostly for static data, such as pictures.
The best would be to replace the harddrive completely with.. say, 8x8GB flash memories connected to act like one volume. And then you could have a free slot around the battery or something for insertion of secondary flash drive.
I don't think a random newspaper that doesn't even focus on technology is a particularly good source. As for Wikipedia, it is self-contradictory, as it also states:
This implies that the limitation only applies to write cycles.
This paper might explain the contradiction/issue with read and write cycles:
It's not a fully published paper (and it's a couple of years old), but the authors work in engineering for space applications. Check out the second paragraph of section 2:
"FRAM data is read using a switched charge that determines the state of the ferroelectric memory. In the process of reading the data, the data is changed; therefore, additional circuitry must be used to re-write the original data back to the memory cell."
This suggests that reading from FLASH involves a write operation?
Comments
Slapping in another DRAM slot on a desktop is easier than on a notebook. DRAM is cheaper than NAND flash. If you're just going to be using it for a cache, then on a desktop, RAM is the way to go.
Yes, but Ram drives are not convenient and just adding ram will not give you the same effect. You can install just about anything to a ram drive, even operating systems, but as soon as you reboot, you have to install everything all over again. I dont know if people still do it, but it used to be fairly common among hardcore PC users to install GLQuake to a ram drive for better frame rates, benchmarks ect... It seems to me like a few years ago there was talk of creating ram drives that would remain powered up even when the PC (we are talking PCs here) were turned off. I don't know what ever became of that idea. My guess is one of two things; either the drives were to volatile and easily corrupted, or the cost was too high for any real market viability. There are raid controllers that allow for copious amounts of ram installed directly on the controller board itself though.
Slapping in another DRAM slot on a desktop is easier than on a notebook. DRAM is cheaper than NAND flash. If you're just going to be using it for a cache, then on a desktop, RAM is the way to go.
RAM would require battery backup.
Steve
Well that part I can agree with.*
Flash is so where it's at, only not quite today.* I'm totally getting a 16gb compact flash card to put in an IDE adapter for my PowerBook, whose hard drive has seen better days anyway.* Currently there's just not enough capacity in flash, but 16 gigs should handle Tiger / Leopard and my apps with some room for swap.* FireWire for the rest.* I'm a finnicky bugger for silence and fancy the experiment.* I dub thee "FlashBook".
Um but yes, the extended hard drive buffer idea of Intel's is sound.* The platforms for future generations of MacBook±Pro should be pretty interesting.
You don't want to swap with flash, that's what's going to kill it with limited write cycles unless the OS regularly moves the swap file location every time it writes, but if you have limited space, that wears it out much quicker. You'll want to max out the RAM to minimize swapping.
My Application directory is 9GB. I suppose I can cull it of lesser-used programs, but it's not going to carry a lot of media or working files for portable use.
I really don't have a noisy notebook drive (I can't even hear it clicking), so the reduced noise is not much benefit to me. Most of the faint noise that my notebook makes is the fan for cooling the hot CPU.
DRAM is cheaper than NAND flash.
What type do USB pocket flash drives use? Those things can fit 4GB in a package the size of a small pack of gum and only cost $100. I have a hard time finding 1GB RAM sticks for much less than $100.
Yes, but Ram drives are not convenient and just adding ram will not give you the same effect. You can install just about anything to a ram drive, even operating systems, but as soon as you reboot, you have to install everything all over again.
RAM would require battery backup.
Steve
Yes, which is why I said specifically...
If you're just going to be using it for a cache,
... to qualify it if it being used for cache only. Obviously it has other applicability for persistent storage.
Yeah that, and with Nand there's a limited amount of times you can read/write to it.
/but they're working on that.
Yeah, I was going to post that as well. I haven't heard much talk about that aspect.
One can write about 100 thousand times to this, but can read more than a million times.
So, while I can see this used for information that won't be changed much, there are newer technologirs for FLASH that will be out that will solve the write problem.
Without that being solved, there is no way that it could be used for a HD replacement.
Check this out.
http://samsung.com/PressCenter/Press...911_0000286481
With Apple being such a big customer of Samsung FLASH, they might be working with them on this already. Let's hope!
interesting, is it a big enough number to the point where it almost doesn't matter?
Nope. See my post above this one.
The math has been done for this *many* times. According to *their* math, it should last for quite some time. Much longer than you will probably retain the notebook. So I wouldn't worry too much.
100 thousand writes can be completed in a few months.
One can write about 100 thousand times to this, but can read more than a million times.
The read cycles of NAND Flash aren't limited; only the write cycles are, and they're a lot higher these days than the often-cited 100,000 times.
That said:
Without that being solved, there is no way that it could be used for a HD replacement.
Very true.
The read cycles of NAND Flash aren't limited; only the write cycles are, and they're a lot higher these days than the often-cited 100,000 times.
That said:
Very true.
Read cycles are limited. Both might be a bit higher than I mentioned, but not much. Those figures are from earlier this year.
Read cycles are limited. Both might be a bit higher than I mentioned, but not much. Those figures are from earlier this year.
I'm genuinely curious; please find me a source that states that NAND flash read cycles are limited.
I remembr you could create a ram disk on the Amiga...many years a go.
You can still create a RAM disk in OS X, but since OS X aggressively caches frequently-accessed data in RAM anyway, it's not as useful any more.
I think that this is a great item for Microsoft, since they have to reboot so often. For me, I reboot when a new security fix requires it. Otherwise, my iBook (my MBP arrives tomorrow) just shuttles from home to work with the lid closed.
Perhaps I am missing a key value to this. Anyone else think that improving the boot time of a MB or MBP is not much of an issue for OSX users? Perhaps Bootcamp users want this!
Well regarding MS, I thought I saw a demo of a laptop running Vista where Vista allowed pda-like operations to take place in a small window on the lid of the laptop. This ran some palm-like apps that could be accessible without even having to open or awaken the computer itself.
I have thought for a while that Apple should be making their laptops more instant on, but they don't need to do it for everything. I don't care that Photoshop takes 5 minutes to load b/c after I start it up, I keep it going for quite a while and over the course of the day the boot time is insignificant. However the fact that iCal takes almost as long to load as Photoshop is exxasperating!!! I want to know within 5 seconds whether I'm late or not.
I think Apple's productivity iApps are perfect to be sitting in a NAND memory buffer so that iCal, AddressBook, Mail, Stickies and Widgets are absolutely available with no waiting. That would make the OS as a whole seem instantaneous. Who cares if Illustrator takes a while, it is an excuse to get another coffee.
I'm genuinely curious; please find me a source that states that NAND flash read cycles are limited.
This is one. I'll quote from it, as well as give the link, as it's a long scroll 'till you get to this. It's interesting though, so you might want to read the whole thing. Where he says 1m read/writes, he really means 1m reads.
"But besides cost, there are other obstacles for Flash memory replacing hard drives. Flash memory is typically guaranteed for around 1m read/write cycles, which sounds a lot, but in the context of the working life of a PC (which is continually writing, erasing or rewriting data) is not. So designers have to use techniques known as wear-levelling to shift data around the Flash memory block to reduce the risk of data error. "We can design around the problem," says Walsh."
http://technology.guardian.co.uk/wee...856508,00.html
Wiki has this, which is, surprisingly correct, but as usual, not totally complete. Look down to where it says EPROM etc. lifetime.
The write life is complete. The read life is correct as far as it goes, in that they do say that it is limited, but they don't say that that limitation is considered to be about 1 million cycles. It isn't cycle limited, it's true, but the charge leakage gets worse with time, just as it does in most capacitors, and that charge drop ends up in a life limitation which usually comes out to 1 million cycles.
http://en.wikipedia.org/wiki/Read-only_memory
When compared to a hard disk drive, a further limitation is the fact that flash memory has a finite number of erase-write cycles (most commercially available flash products are guaranteed to withstand 1 million programming cycles) so that care has to be taken when moving hard-drive based applications, such as operating systems, to flash-memory based devices such as CompactFlash.
This implies that the limitation only applies to write cycles.
I don't think a random newspaper that doesn't even focus on technology is a particularly good source. As for Wikipedia, it is self-contradictory, as it also states:
This implies that the limitation only applies to write cycles.
There are quite a few other sources.
You can go and look if you want to see this that badly. They all say about the same thing.
In fact, most Flash cards have only about 10,000 write cycles.
Most information is concerned with writes, because it is so poor.
Leveling does help. But mostly for static data, such as pictures.
I don't think a random newspaper that doesn't even focus on technology is a particularly good source. As for Wikipedia, it is self-contradictory, as it also states:
This implies that the limitation only applies to write cycles.
This paper might explain the contradiction/issue with read and write cycles:
http://snipurl.com/xkma
It's not a fully published paper (and it's a couple of years old), but the authors work in engineering for space applications. Check out the second paragraph of section 2:
"FRAM data is read using a switched charge that determines the state of the ferroelectric memory. In the process of reading the data, the data is changed; therefore, additional circuitry must be used to re-write the original data back to the memory cell."
This suggests that reading from FLASH involves a write operation?
J