Why no PCI-e RAMdisk?

[Smoblikat]

I know there are a couple PCI disks and ive seen at least one SATA RAmdisk, but why no PCI-e RAM disks? DDR3 8gb DIMMS are cheap, a 64 GB RAMdisk will offer significantly better performance that an SSD, so why arent there any?

 

[corkyg]

Seems like the market is insufficient to justify the investment.

 

[exdeath]

What investment? One of the numerous cheap Chinese manufacturers could slap together a PCI-e card, DRAM controller, DIMM sockets, and a battery connector for like $3 and sell it for $39

 

[ShintaiDK]

Because its a horrible idea. Its also tried before and failed hard.

 

[Charles Kozierok]

I think the main issue is that there really is no compelling reason to want a RAM disk any more. RAM itself is cheap and plentiful, operating systems generally cache things intelligently, and fast SSDs make the delta between a "real" disk and a volatile one too small to provide much appeal.

 

[Magic Carpet]

Because its a horrible idea. Its also tried before and failed hard.

I am still using it. The best thing about it, is volatility. No need to perform time-consuming writes to erase sensible data :thumbsup:

I'd buy another, any day. Too bad, they stopped making them.

 

[exdeath]

I think the main issue is that there really is no compelling reason to want a RAM disk any more. RAM itself is cheap and plentiful, operating systems generally cache things intelligently, and fast SSDs make the delta between a "real" disk and a volatile one too small to provide much appeal.

Not really. 550 MB/sec and ms access time is still a far cry from 50,000 MB/sec and ns access time, let alone random access.

The main issue in the past was 1) ram was expensive and too small , and 2) keeping data backed up to a slow HDD for power loss protection was a pain.

It would be interesting to see a 128 GB ram drive with built in battery power and seamlessly backed to a 128GB SSD.

Ideally though, I just want 4 x 256GB non volatile STT-MRAM DIMMs to stick in my system board and eliminate the need for storage devices altogether.

 

[corkyg]

What investment? One of the numerous cheap Chinese manufacturers could slap together a PCI-e card, DRAM controller, DIMM sockets, and a battery connector for like $3 and sell it for $39

I guess you have never run a business. A hobbyist could do that - sure, but to gear up a production line and then set up worldwide distribution for hundreds of thousands of something that was tried before and failed? Even "cheap Chinese" manufacturer's have to make a profit. And it does require considerable investment.

 

[fuzzymath10]

RAM is maybe $5/GB (give or take) depending on what kind you get. That is much more than SSD where you're south of $1. You could do many things faster than a rotating platter drive could do, but I'm not so sure about SSD vs RAM, apart from pretty bar graphs or big numbers or showing the Windows copy dialog box showing a crazy value. Perhaps for a very specialized task involving substantial 24/7 writes which, if you're unlucky, might destroy your SSD after a few years (instead of 20 ) or if you have something to hide from the authorities

 

[Smoblikat]

RAM is maybe $5/GB (give or take) depending on what kind you get. That is much more than SSD where you're south of $1. You could do many things faster than a rotating platter drive could do, but I'm not so sure about SSD vs RAM, apart from pretty bar graphs or big numbers or showing the Windows copy dialog box showing a crazy value. Perhaps for a very specialized task involving substantial 24/7 writes which, if you're unlucky, might destroy your SSD after a few years (instead of 20 ) or if you have something to hide from the authorities

I would rather drop 400$ for 64gb RAM and have it be truly instant speed and unlimited speed, than I would spending that money on SSD's that are essentially flash drives with a fast interface.

 

[KingFatty]

I would rather drop 400$ for 64gb RAM and have it be truly instant speed and unlimited speed, than I would spending that money on SSD's that are essentially flash drives with a fast interface.

But what if you spent $400 on a bunch of relatively inexpensive 64GB SSDs and put them all in a massive RAID. Surely that would be pretty damn fast (though still not near a RAM drive, but it would approach a point where a human may not be able to notice for normal use).

 

[Smoblikat]

But what if you spent $400 on a bunch of relatively inexpensive 64GB SSDs and put them all in a massive RAID. Surely that would be pretty damn fast (though still not near a RAM drive, but it would approach a point where a human may not be able to notice for normal use).

Each drive would need to be configured, maintained and if one died we would lose the entire array, unless we used mirroring but then we would need double drives. It takes so many SSD'd to barely touch a RAMDisk in terms of speed. I think a single bus, single power plug solution that is almost infinitley faster is much better than a couple dozen SSD's.

 

[veri745]

almost infinitley faster

A couple orders of magnitude is "infinite"?

I guess have a HDD that is infinitely larger, but can't transfer any data at all.

Also my CPU does infinitely many more computations/second than the one I had 10 years ago, so I never need to upgrade again.

 

[bradley]

I would rather drop 400$ for 64gb RAM and have it be truly instant speed and unlimited speed, than I would spending that money on SSD's that are essentially flash drives with a fast interface.

So true. Finally these glorified flash drives with intelligent controllers are at a decent pricepoint. Otherwise I was soooo tempted to go the RAMdisk route myself.

 

[Magic Carpet]

It would be interesting to see a 128 GB ram drive with built in battery power and seamlessly backed to a 128GB SSD.

And the price might be?

 

[GrumpyMan]

Because its a horrible idea. Its also tried before and failed hard.

We use these on all our workstations that are used for postal presorting and CASS certifying of data used for all mailings. Used to compare mailing lists to the USPS's national database to verify if they are indeed real and deliverable addresses in order to be able to print Intelligent Mail Barcodes on the mail for speedy delivery by the USPS.
Without one of these the software used runs at 256,000 records an hour, with one of these on the work station it runs at 5-7 million records an hour depending on the data and how many addressing elements are in it. There is a small back up program that saves and installs all data on it in a matter of seconds upon power failure should the batteries not work on them.

 

[Lorne]

Yup, Want, Been wanting one for along time.
A newer DDR3 PCIe version would be great.

 

[dave_the_nerd]

Because its a horrible idea. Its also tried before and failed hard.

Note the SATA connector. It capped at SATA speeds.

What's the theoretical IOPS max of a SATA 3 connector vs. PCI-E?

 

[exdeath]

Hmm... PCIe x16 RAM "disk" cards with SLI...

 

[Lorne]

Im thinking SLI would be somewhat pointless as it mainly a sync source port unless your thinking RAID0. (x32) Which will still only get you 16GBps
I would still want one though at PCIe x16 with 8+GB, Just for cache and splash drive perposes.

 

[Denithor]

http://www.acard.com/english/fb0101.jsp?type1_title=SATA RAM Disk &ino=28

Here's the updated, DDR2 version of the device linked above. Includes battery for backup in case of power outage.

Haven't heard of anyone releasing either a DDR3 SATA or PCIe model. Would actually be an interesting device.

Of course, another option would be to simply build an X79 system, install 64GB of RAM and designate like 50GB or whatever to a true RAM disk.

EDIT: And here's a thread detailing the performance of these drives.
http://forums.anandtech.com/showthread.php?t=234368&highlight=acard

 

[rsutoratosu]

I still have the iram, i need to replace the battery but it still works great.. i use it for swap files now.. used to have 4 cards, but due to pci slots, only 1 card per pc.. either that or it sits on the shelve doing nothing

 

[ALIVE]

http://www.acard.com/english/fb0101.jsp?type1_title=SATA RAM Disk &ino=28

Here's the updated, DDR2 version of the device linked above. Includes battery for backup in case of power outage.

Haven't heard of anyone releasing either a DDR3 SATA or PCIe model. Would actually be an interesting device.

Of course, another option would be to simply build an X79 system, install 64GB of RAM and designate like 50GB or whatever to a true RAM disk.

EDIT: And here's a thread detailing the performance of these drives.
http://forums.anandtech.com/showthread.php?t=234368&highlight=acard

i have 2 of them
and those babies are so fastttttttttttttt
and the cf card makign storage and restore a matter of minutes
power is off and you have a cf pluged then it auto backup to the cf
so no worries there
i had the version with the 8 dimm slots 8x2gb=16gb total
it has 2 sata ports and you can split the drive in 2 drives and use both sata ports. 2 drives with half of capasity
so you can put the one as raid0 for 300mb speed
it is limited in sata2 or sata1 internally somewhere
i have 2 acard 9010
so i put them in 4xraid0 for a total of 600mbyte/sec
and i do not have to worry about any wavering or what ever
i can even defrag them lol

 

[Concillian]

What is small enough to fit in a RAM disk these days?

I tried this with a RAM disk and 16GB RAM at one point... the problem was that anything I wanted to put in the RAMdisk was bigger than 10GB. Seems like you'd want at least 32GB to be useful, and by the time you talk about the price of the card + RAM, you're looking at a 256GB SSD that is almost as fast and way more useful long term.

As Denithor mentions, this can pretty easily be done with software RAM disks, that seems like the better solution. These cards ended up being very low volume, and so high cost. With the emergence of the consumer level (low price) SSD, the benefit of this kind of thing is smaller than ever.

 

[Smoblikat]

A couple orders of magnitude is "infinite"?

I guess have a HDD that is infinitely larger, but can't transfer any data at all.

Also my CPU does infinitely many more computations/second than the one I had 10 years ago, so I never need to upgrade again.

Good for you, I wish my CPU was infinitley fast.....too bad the only thing that is is my RAM compared to an SSD's access time.