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Flash Memory and Apple iPods and Laptops
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This problem existed with earlier Flash technology, but has long been solved. Current Flash memory cells can be rewritten so many times that it isn't really an issue anymore, plus the Flash memory controllers use a technology called "wear leveling". Basically, if you have a particular memory location that gets changed a lot, it keeps on moving it around.
In an earlier thread, somebody calculates that it takes like 100 years of constant writing to such a drive to wear it out.
On the speed issue, the access is about 0.11 ms vs about 17ms for a HDD.
Good for transactional stuff.
On the throughput issue, it is about 65MB/s or 1.5-2x that of a HDD.
Good for HD video viewing.
The cost even after SDD drops ANOTHER 50% is about $175/32GB or $5.47/GB. Extremely expensive.
Rocketman
Good for transactional stuff.
On the throughput issue, it is about 65MB/s or 1.5-2x that of a HDD.
Good for HD video viewing.
The cost even after SDD drops ANOTHER 50% is about $175/32GB or $5.47/GB. Extremely expensive.
Rocketman
Reading this on Engadget earlier reminded me of a presentation I did in my degree about 4-5 years ago now. I only explained the technology and didn't really make any predictions to the future of the media, but if I had done I can guarantee I would have been way off in either direction.
While it seems to be accelerating at the moment, it has taken quite a while to get to this stage and I remember when 32-64MB flash drives were £50-100. We now see a 32GB drive going for about £180, (straight conversion $>£), and the future certainly looks flash based. Mechanical drives really are causing the slowdown in development of portable devices becoming faster, (I refer to laptops and PMPs of course here). Once cost is low enough not to matter, I say get them in there as standard. Until then, it would be nice if Apple either put them into the higher spec 15" MBP and 17" models, or at least give an option for us to choose for a little more. I know it would make them a little bigger. I know some 15" laptops and most 17" models are shipping with two drives, why not make one of them flash? Alternatively, one drive, hybrid.
I do still worry about read/write cycles, but that will come as time goes on. Apple have signed deals for large quantities of flash before, (which largely turned out for the iPod nano), it would be a great time to either expand these or sign more deals with others.
While it seems to be accelerating at the moment, it has taken quite a while to get to this stage and I remember when 32-64MB flash drives were £50-100. We now see a 32GB drive going for about £180, (straight conversion $>£), and the future certainly looks flash based. Mechanical drives really are causing the slowdown in development of portable devices becoming faster, (I refer to laptops and PMPs of course here). Once cost is low enough not to matter, I say get them in there as standard. Until then, it would be nice if Apple either put them into the higher spec 15" MBP and 17" models, or at least give an option for us to choose for a little more. I know it would make them a little bigger. I know some 15" laptops and most 17" models are shipping with two drives, why not make one of them flash? Alternatively, one drive, hybrid.
I do still worry about read/write cycles, but that will come as time goes on. Apple have signed deals for large quantities of flash before, (which largely turned out for the iPod nano), it would be a great time to either expand these or sign more deals with others.
Careful with the bits and bytes. You got the number right, but not the units. "mb" is megabits, while "MB" is megabytes per second. 65mb/s is about 8 MB/s, which is pretty slow. The Sandisk SSD drives are spec'ed at 62 MB/s for reading, and 36 MB/s for writing. A Seagate Momemtus 7200.2 2.5" hard disk for notebooks supports 59MB/s sustained in either direction.
Everyone is so concerned about read/write.
I don't think companies would be foolish enough to release a product that doesn't last at least 3 years, and I hope 5+.
Under Apple Care don't those drives have to work for 3 years at least? Which is still not really ideal, but it is much greater then what it seems people are making it out to be.
I am definitely interested in how this will turn out, but confident it won't be nearly as tragic as people make it out to be. At the very least Hybird so we can still take a lot of advantage of the flash technology.
Someone gave stats about Vista ONLY loading 1.5 times faster and XP 2.5 faster, I happen to think thats a pretty big improvement and it will be interesting to see how fast OS X will load using this technology.
I am looking forward to this.
I don't think companies would be foolish enough to release a product that doesn't last at least 3 years, and I hope 5+.
Under Apple Care don't those drives have to work for 3 years at least? Which is still not really ideal, but it is much greater then what it seems people are making it out to be.
I am definitely interested in how this will turn out, but confident it won't be nearly as tragic as people make it out to be. At the very least Hybird so we can still take a lot of advantage of the flash technology.
Someone gave stats about Vista ONLY loading 1.5 times faster and XP 2.5 faster, I happen to think thats a pretty big improvement and it will be interesting to see how fast OS X will load using this technology.
I am looking forward to this.
Yes, but maybe prices will come down, I remember a 10 Meg (not Gig) selling for 200. May take another 3 more years to come down to $1.00 a gig.
Umm, if you've got about $10 to spare for a 1GB flash drive, you could get a rough concept of speed by putting OS X on a flash drive now. I haven't tried OSX but have been using Linux on a thumb drive for some time now, and find it rather speedy...
Thanks for the info, good to know
Well all we need now is lower prices and higher capacity drives and I'm there
For the sake of speeding up the boot process, which is very important to me -- especially when starting up a machine at the beginning of a meeting or class, I'd like to see at least a SSHD for the boot device (and the current 32Gb would easily suffice), and then a conventional (as I write this in 2007 ) drive as a second volume with most of my software and data on it.
That would allow me to get the machine booted quickly, and still have 200Gb of storage onboard for databases, big graphic files, and virtual machines.
) drive as a second volume with most of my software and data on it.That would allow me to get the machine booted quickly, and still have 200Gb of storage onboard for databases, big graphic files, and virtual machines.
If I could get this a BTO option on a MBP that would be great. I'd totally go for it even if it was the full $350. I tend not to use much space on my laptop, just stuff that's frequently accessed and I need fast. Everything important goes on an external disk.
With this disk in a new MBP with LED backlight, lower power consumption WiFi, 10.5, Time Machine and a USB disk on an AirPort base station I'd be totally set up.
With this disk in a new MBP with LED backlight, lower power consumption WiFi, 10.5, Time Machine and a USB disk on an AirPort base station I'd be totally set up.
Absolutely
You spend $1000s upgrading your computer's processor etc and you still have the same hard drive tech that's been aound for 10 years. What's the story with that!!!
However, wouldn't a flash- HD hybrid be something of a good idea. I mean how big is the market for a computer with 16 gig storage??? It seems like we are going backwards!!! Unless Apple comes out with some ultra funky notebook, I think it will be a bomb!!
You spend $1000s upgrading your computer's processor etc and you still have the same hard drive tech that's been aound for 10 years. What's the story with that!!!
However, wouldn't a flash- HD hybrid be something of a good idea. I mean how big is the market for a computer with 16 gig storage??? It seems like we are going backwards!!! Unless Apple comes out with some ultra funky notebook, I think it will be a bomb!!
As soon as portable computer memory controllers allow more than 3GB, ramdrives even for virtual machines become practical. The HDD is a "boot and archive volume", but an 8GB ramdisc becomes the primary compute space.
In that world, SDD is relegated to only the most space and mass limited applications, and "laptop format" devices can keep the very low cost HDD.
Solid state drives can also be operated at higher altitudes
I think the iPhone specs as discussed are UPOD.
Rocketman
In that world, SDD is relegated to only the most space and mass limited applications, and "laptop format" devices can keep the very low cost HDD.
Solid state drives can also be operated at higher altitudes
I think the iPhone specs as discussed are UPOD.
Rocketman
MTBF vs. Write/Erase cycles
These are two measures. The Mean Time Between Failure which is not specific to the write/erase but rather overall expected failure of the card. The SDD drive I read today listed as 1,000,000 hrs or ~115 years.
The write/erase cylce though is spec'd at 300,000 cycles. This is relatively high but under certain applications could be exhausted quickly. This is why, as you note, they implement "wear levelling" which essentially aims to move written data around to minimize the issue by not repeatedly writing to the same location. Reading data has no impact on the life of the drive.
Overall, though I would suspect very good in field life of the flash drives compared to magnetics. You just don't have the mechanics to worry about. The price difference though is significant and won't close any time soon. I think hybrid or combination setups will be common. Get the immediate/instant on benefit of 32GB SDD flash and still have the 500GB storage of the HDD.
These are two measures. The Mean Time Between Failure which is not specific to the write/erase but rather overall expected failure of the card. The SDD drive I read today listed as 1,000,000 hrs or ~115 years.
The write/erase cylce though is spec'd at 300,000 cycles. This is relatively high but under certain applications could be exhausted quickly. This is why, as you note, they implement "wear levelling" which essentially aims to move written data around to minimize the issue by not repeatedly writing to the same location. Reading data has no impact on the life of the drive.
Overall, though I would suspect very good in field life of the flash drives compared to magnetics. You just don't have the mechanics to worry about. The price difference though is significant and won't close any time soon. I think hybrid or combination setups will be common. Get the immediate/instant on benefit of 32GB SDD flash and still have the 500GB storage of the HDD.
Umm, if you've got about $10 to spare for a 1GB flash drive, you could get a rough concept of speed by putting OS X on a flash drive now. I haven't tried OSX but have been using Linux on a thumb drive for some time now, and find it rather speedy...
I installed Tiger on my 8GB nano once. When you install OSX, it asks you on what drive you wanna install it, and my nano happened to be plugged in. So I could choose between the Macintosh HD and the black iPod icon. I was intrigued by this and installed OSX on the iPod.
LEt me tell you that everything felt almost twice as fast, booting, copying files, etc. But I was concerned with the limited read/write cycles of the nano's flash memory, so I quickly reinstalled OSX on the regular hard drive. Note that the nano was plugged in over USB, not the best interface for the system drive in terms of speed.
Excellent idea, what is the space requierment again for Tiger, as I do have a 2GB flashdrive laying around....
The swap and journaling filesystems in common use on *nix-like systems (including OSX) are the type things that has the potential to wear out flash, even if wear leveling is used... In the Linux world, jffs2 is in development, which is a read/write, compressed, journaling Flash filesystem that is designed to be used on Flash memory devices. In other words it's an effort to avoid some/much of the flash wear problem, and Apple will likely have their own "solution" to the wear problem soon (if not sooner!).
Interesting news article I just stumbled upon; there already is a solid state harddisk of 128Gb. Read/write speeds are a bit slow but it's quite some capacity and fast access times. Also a very long lifetime (over 100 years!). I wonder how much it costs...
source: http://www.dailytech.com/Super+Talent+Announces+New+SATA+SSDs/article6475.htm
source: http://www.dailytech.com/Super+Talent+Announces+New+SATA+SSDs/article6475.htm
You mean you don't care if your hard drive crashes? That is the equivalent of a massive flash drive failure.
But I think Flash may be a touch better in that it probably doesn't fail all at once like a hard drive. Does anyone know this?
You spend $1000s upgrading your computer's processor etc and you still have the same hard drive tech that's been aound for 10 years. What's the story with that!!!
However, wouldn't a flash- HD hybrid be something of a good idea. I mean how big is the market for a computer with 16 gig storage??? It seems like we are going backwards!!! Unless Apple comes out with some ultra funky notebook, I think it will be a bomb!!
I totally agree. Hard drives have been around for ages. There have ben some technology advancements like perpendicular recording to get way more data on the same space, but you still have the moving parts and the fact that it's magnetic storage.
For storage, we want two thing: higher speed (to keep up with the computing components) and higher capacity. HDDs have done a good job for capacity increases, but speed bumps are marginal. The memory speed problem has been solved by incorporating different levels of memories into computers, namely HDD, main memory, L3 cache, L2 cache (on die), L1 cache (where instructions are separate from data) and finally registers that are in the processors native sizes (32 bit or 64 bit). So the smaller it goes, the faster it is.
I see flash as ideal to fill the gap between a huge hard drive and the main memory. The best thing is, flash is not volatile memory (i.e. data stays on them even when there is no power) so you could keep things that require fast access on there (OS, Page Files, Virtual Machines and Memory), basically things that should be in RAM but are moved out because there is not enough RAM.
Hybrid drives like Seagtes makes them right now are the way to go I think. Hard Drives will be around for a while because of the low cost per GB. And if you put them together in a RAID, you get some serious speed boosts and/or redundancy. Flash is great for everything that is made for moving it around because there are no moving parts, it's lightweight and smaller, easier on power, not sensible to magnetism so much, more resistant to temperature and and pressure and has better access times.
Flash for iPod, phones, PDAs is a must, those devices get dropped and the hard drives is usually dead when it was in use at the time of impact. High end laptops (all Apple since 2005 have the sudden motion sensor) usually park the hard drive before it hits the ground so there's less chance for a head crash on impact. I don't know if iPods have this.