Question about why RAM uses chips - Hardware & Software

I was thinking about how RAM is memory and I thought "Why not just buy a TB external hard drive and use that as RAM, so you can have a TB of RAM?" What I would like to know is why Ram uses chips instead of a hard disk that has more memory it can store? Sorry if this question is completely retarded, but I have no idea why it isn't just a disk instead.

hahhahahahahhahahaha [editline]5th September 2011[/editline] also helpful: hard disk speeds = slow mobo chipsets = fast as fuck

Name fits

Basically because harddrives, and even SSDs don't even go near the speed of RAM chips. I imagine in the future when harddrives or whatever we have will be fast as fuck, RAM might not be needed.

Pagefile.

Pagefile is slow and gross and oh my god.

Hard disks are on the order of < 1 GB/sec and 6ms latency, RAM is on the order of 40 GB/sec and < 1ms latency.

[QUOTE=Warship;32123868]Basically because harddrives, and even SSDs don't even go near the speed of RAM chips. I imagine in the future when harddrives or whatever we have will be fast as fuck, RAM might not be needed.[/QUOTE] We will probably always have RAM. No matter how fast HDD/SSDs get there will always be something faster, but volatile or more expensive.

[QUOTE=dbk21894;32123906]Pagefile is slow and gross and oh my god.[/QUOTE] Yeah I know, I was going to edit it in. [editline]5th September 2011[/editline] It just solves the threads question that's all.

[IMG]http://i50.tinypic.com/r77myv.jpg[/IMG] I made this image sometime ago. It should pretty much explain everything to you. The RAM sticks used for that RAMDISK are nowhere near the "top of the line" ones. They are merely budget 533mhz DDR2 sticks.

[QUOTE=Warship;32123868]Basically because harddrives, and even SSDs don't even go near the speed of RAM chips. I imagine in the future when harddrives or whatever we have will be fast as fuck, RAM might not be needed.[/QUOTE] What he said. There are many other complications as well.

Isn't it also because HDDs have different data structures from RAMs (with 4kb chunks and all that stuff)?

[QUOTE=B!N4RY;32124584] I made this image sometime ago. It should pretty much explain everything to you. The RAM sticks used for that RAMDISK are nowhere near the "top of the line" ones. They are merely budget 533mhz DDR2 sticks.[/QUOTE] Thanks, now I know.

[QUOTE=TerabyteS_;32134181]Isn't it also because HDDs have different data structures from RAMs (with 4kb chunks and all that stuff)?[/QUOTE]Nope, just purely because its just too damn slow. The thing is OP, its not purely the quantity of RAM that matters anymore. 4 GB is more than enough for a vast majority of applications. The reason why having inadequate RAM was a problem in the past and made your computer so slow was because you would have to fall back on the page file. And if anyone remembers back in the day when 64 MB was standard when you ran Windows 2000, it was SLOWWWW.

nobody really explained WHY the latency is large hard drives have a seek time because hard drives literally have to move an arm to read the drive platter, it only takes a couple dozen milliseconds but files aren't all stored in a straight line so there's a lot of arm movement. it all happens in less then a second, but it's comparatively slow as shit hard drives don't read or write nearly as fast as solid state memory (rom, ram, flash, etc) because solid state memory doesn't have to deal with seek time or seeking data on a platter, it's all right there on the chip. not to mention that ram is volatile memory and has been designed to be as fast as possible so it's even faster than other flash memory

If you've ever run out of memory while playing a videogame, you'll know why computers don't just use hard drives and pagefiles. The framerate suddenly drops down into the single digits because the hard drive is so slow and games often need immediate access to a lot of data. That's why it's loaded into RAM, and why games have loading screens. It's possible to have a system with no memory, but it's going to be slow as shit, regardless of how fast the CPU is.

[QUOTE=Cheesemonkey;32139912] hard drives don't read or write nearly as fast as solid state memory (rom, ram, flash, etc) [/QUOTE] Not necessarily true. If you compare a single platter hard drive to one typical flash memory chip, the speed is generally incomparably faster. The reason why decent SSDs are faster than conventional HDDs is because they are consisted of many NAND chips, and when a file is written to it, the file is striped down and written across all of the NAND chips spontaneously. Also, RAM is volatile and does not belong in the same category as ROM and Flash, as they are non-volatile. They are the complete opposite of each other.

[QUOTE=B!N4RY;32144239]Not necessarily true. If you compare a single platter hard drive to one typical flash memory chip, the speed is generally incomparably faster. The reason why decent SSDs are faster than conventional HDDs is because they are consisted of many NAND chips, and when a file is written to it, the file is striped down and written across all of the NAND chips [B]simultaneously[/B]. Also, RAM is volatile and does not belong in the same category as ROM and Flash, as they are non-volatile. They are the complete opposite of each other.[/QUOTE] Fixed. Imagine modern SSD drive as small portable RAID array of ssd drives. That also explains why the ssd controllers are so important to the overall performance. (inserd yo dawg in there please). Ad volatility/non-volatility - volatile storage needs to be continuously powered not only to store and retrieve data, but keep them stored as well. That means power consuption goes through the roof and your data are vulnerable in event of power failure. This however did not stop manufacturers to offer special sata/pcie drive enclosures. Behold the fastest drive you ever seen! [IMG]http://techreport.com/r.x/gigabyte-iram/card.jpg[/IMG] [URL="http://www.anandtech.com/show/1742"]http://www.anandtech.com/show/1742[/URL] [URL="http://techreport.com/articles.x/9312"]http://techreport.com/articles.x/9312[/URL]