Post by Gary on Aug 3, 2009 13:01:02 GMT -5
So with all of the chatter about Solid State Drives (SSD's), I figured I would give you all some real information about the technology. There are 2 kinds of flash memory. NOR is a lower capacity silicon that allows both storage and executable commands (programming). NAND is higher capacity silicon that allows only storage of data. As most SSD's are NAND that is what I will be covering here. NOR is what is in most cell phones and PDA's.
As the technology has become cheaper, it has become more mainstream. By 2010 we will see about 20 percent of all laptops using SSD's instead of the spinning discs (HDD's). Larger server system arrays will be using it more and more. Digital Media down-load services will pretty much rely on SSD. This has some advantages and some disadvantages.
The advantages are many but the technology does have a ways to go before I can recommend it for the home user. The read and write speeds are blazingly fast. They can be made much smaller than standard HDD's. They aren't affected by motion like a spinning disk. They are almost indestructible compared to HDD's. And they are coming down in price so that home users can afford them. They also have persistent memory.
While that may sound great there are some serious disadvantages. The biggest is lifetime for write capability. As they get used the ability to write to each "sector" diminishes. After an extended period of use they become essentially a read only device. This is fine for a media download server as they just need to push out data. It is horrible for the over-clockers and bench testers out there that are reading and writing to the same areas repeatedly. The Velociraptors from Western Digital are almost as fast and don't have the degradation problem. Most lower end SSD's use a stripping technology similar to raids and size depends on the number of flash chips in the drive. While this is good for speed, it can be really bad as wear leveling takes over. This is when you lose the write/erase function on one of the chips and it has to make up for it somewhere else.
Another big problem with write speed is the blocking. The write/erase blocks for SSD's are much bigger than the sectors used in HDD's. This tends to mean small writes take just as long as big ones. For general use that does effect performance. And if you are doing overclocking it can kill you as you lose the speed gained in CPU to the loss in write speed.
Another big disadvantage is size. In order to get a larger storage device you need to add more chips, and then change the way the array is read. While they are working the bugs out of the a 500 gig drive and trying to get it down to a decent size, you can go out and get a laptop drive that can hold that much data easily.
The biggest down-fall of the SSD is still the price. A basic breakdown works out to be about 20 times the cost per gig than a standard HDD of any decent size.
So in conclusion, if you are building a media server SSD is probably the way to go as access to data fast is the most important feature. If you are looking for a good hard drive for just about anything else, stay away from them until they technology gets both better and cheaper.
As the technology has become cheaper, it has become more mainstream. By 2010 we will see about 20 percent of all laptops using SSD's instead of the spinning discs (HDD's). Larger server system arrays will be using it more and more. Digital Media down-load services will pretty much rely on SSD. This has some advantages and some disadvantages.
The advantages are many but the technology does have a ways to go before I can recommend it for the home user. The read and write speeds are blazingly fast. They can be made much smaller than standard HDD's. They aren't affected by motion like a spinning disk. They are almost indestructible compared to HDD's. And they are coming down in price so that home users can afford them. They also have persistent memory.
While that may sound great there are some serious disadvantages. The biggest is lifetime for write capability. As they get used the ability to write to each "sector" diminishes. After an extended period of use they become essentially a read only device. This is fine for a media download server as they just need to push out data. It is horrible for the over-clockers and bench testers out there that are reading and writing to the same areas repeatedly. The Velociraptors from Western Digital are almost as fast and don't have the degradation problem. Most lower end SSD's use a stripping technology similar to raids and size depends on the number of flash chips in the drive. While this is good for speed, it can be really bad as wear leveling takes over. This is when you lose the write/erase function on one of the chips and it has to make up for it somewhere else.
Another big problem with write speed is the blocking. The write/erase blocks for SSD's are much bigger than the sectors used in HDD's. This tends to mean small writes take just as long as big ones. For general use that does effect performance. And if you are doing overclocking it can kill you as you lose the speed gained in CPU to the loss in write speed.
Another big disadvantage is size. In order to get a larger storage device you need to add more chips, and then change the way the array is read. While they are working the bugs out of the a 500 gig drive and trying to get it down to a decent size, you can go out and get a laptop drive that can hold that much data easily.
The biggest down-fall of the SSD is still the price. A basic breakdown works out to be about 20 times the cost per gig than a standard HDD of any decent size.
So in conclusion, if you are building a media server SSD is probably the way to go as access to data fast is the most important feature. If you are looking for a good hard drive for just about anything else, stay away from them until they technology gets both better and cheaper.