Solid State Drive as Virtual Memory/Paging?

Does anyone know of using a "FAST" Solid State Drive as Virtual Memory/Paging?

It's just an idea that came to be while going through advance menu in XP.

I figure if they make extremely fast SSDs, then you could probably use an 20GB(being that I doubt they will make 'em any lower) drive just for Memory/Paging. Or even just use 5GB of that.

Does this sound doable? And what would be a good write speed for this?

And I'll even throw a far out question. Do you think a SSD can ever replace RAM sticks, OR Vice Versa? Maybe a huge motherboard change will be required as I can picture a gigantic drive/stick with many chips on it to attach to the motherboard.

 

If I had a reasonably fast 20Gig SSD I'd just install Windows and the swap on it. Then BAM you wouldn't even worry about the Pagefile.

I'm waiting for the PCI-E Sandisk.

As for now there's no way of doing it.

 

Just looked up the PCI-E Sandisk. SWEET.

Much better than the bulky external drive out now.

And correct me if I'm wrong, but it would save battery life too.

 

It sure will. Using the harddrive only when you need to access or load a program.

 

Hmm, good idea actually.
A SSD has awesome access time, but similar (or worse) read/write throughput than regular harddrives.
But the thing about the pagefile is that it is basically tiny 4KB reads or writes, as individual pages are swapped in or out. Seems like a good fit for SSD's.

Nope. SSD's are still *a lot* slower than RAM, and that isn't going to change.
The big split is volatile vs. non-volatile RAM (If you know this already, I apologize, but might be helpful to others).
Volatile RAM loses its contents when it loses power. Regular RAM is an example of this type of memory. (SDRAM which you use in your RAM sticks, and SRAM which is used for CPU cache, are both examples of this)
The nice thing about it is that it's generally very fast
Nonvolatile RAM (or NVRAM as you might see it called during POST bootup) keeps its contents even without power. SSD disks are an example of this, as are USB memory sticks, or even your BIOS chip.
And what they have in common is that they're slow as hell (compared to other types of RAM).

Obviously, volatile RAM will always be useless for storing data, that's why it's volatile. Going the other way (using NVRAM on your RAM sticks) is theoretically possible, but you need to solve the speed problem before it becomes worthwhile. Your best bet for that is magnetic RAM, or one of those other new technologies they're playing around with. If they ever become ready for use, we may see nonvolatile RAM used as primary memory, and that would absolutely rock. No need for harddrives or hibernate-files. Instant-on everything, all your data is in RAM when you boot.

If that ever happens, it'll solve *a lot* of problems. But not today...

Just chiming in here, I'd be wary of external drives. I haven't looked up the numbers, but I'd expect external drives to suffer a hit to access time, which you might not want. (Don't know if it'd be enough to make a noticeable difference though)
PCI-E does sound optimal.
Also, yeah, if you put your pagefile on one of these, your main HD could probably power down a lot more often. You might want put your temp folder, and various log files and such on the SSD as well, since those are regularly used as well. But yeah, definitely sounds like a promising idea.

 

And another reason flash can't be used for RAM is that flash memory is not truly randomly accessible. NOR flash can be randomly read but still has to be erased in blocks.

 

That's not really a problem.
Your PC can't address individual bytes either (I'm not 100% sure if it's a limitation of RAM or CPU). It accesses chunks of 32 bit at a time, similar to the blocks you have with flash.

So that at least can be worked around.

 

SSDs aren't really any faster than regular drives at this point, except for random access. As stated, the write performance of them is miserable, which makes them not really suitable for pagefile use. The better money would be spent on more RAM, so you don't have to hit the pagefile to begin with.

 

Pagefiles don't need much write performance. The savings in access time would probably (my guess) make up for the write throughput.

Keep in mind that each page is 4KB, and the OS typically swaps only a few pages at a time. For small reads/writes like that, the saving in access time is *huge*, and the write time isn't too bad at all. I think it'd work fairly well. But I haven't tested it...

 

much ado about nothing.

i have 2 GBs with vista ultimate/ubuntu and never hit more than 1GB usage. i only have 256 swap file size because some apps require a swap file. if that wasn't true, i would delete it altogether.

the idea is to NOT USE THE SWAPFILE AT ALL instead of thinking of ways to make it bigger and use it more.

 

OK, I get it ........RAM is king, forget Virtual Mem/Swap all together.

Now my question is, can the chips on SSD's work like RAM or are RAM chips completely differ?

 

The chips are very different. One of the big problem with flash RAM is that you need to rewrite it an large chunks, not just a few bytes at a time. Also it is very slow. SRAM on the other hand is very fast, but need to always have electricity refreshed on it every few milliseconds. There are some other RAM technologies in the works that are both fast and non-volatile, but they are still in the lab.

There's much more than I can say about the differences. I bet a trip to wikipedia would get you a lot more information.