[SOLVED] Can RAM hold data after switch-off using a battery?

[guymarshall]

I know that RAM is volatile memory so it can only retain information when it has power supplied to it, and devices such as HDDs and SSDs retain their information without a power supply, can RAM be turned into normal storage by just having a battery powering it when the system is not turned on, and charging the battery when the system turns on?

Surely this would mean rapid data transfers, no noise from HDDs, no damage to blocks from SSDs...

 

[USAFRet]

Theoretically, yeah, you probably could.

Problems?
1. Don't let the battery die
2. Have a big wallet.

The circuitry needed is probably a bit more involved than "by just having a battery powering it"

 

[guymarshall]

Theoretically, yeah, you probably could.

Problems?
1. Don't let the battery die
2. Have a big wallet.

The circuitry needed is probably a bit more involved than "by just having a battery powering it"

I suppose the main problem is the fact that a 4TB HDD is £80, whereas 8GB of RAM is £80... And also yeah as you said, the battery must be quite beefy, but if all of those things are fixed, why don't companies do it?

 

[kanewolf]

That is exactly what many RAID controllers do. They have a battery to ensure that any data cached on the RAID card is written to disk or is protected on the card. Batteries work OK for short (hours) of power outage. But they aren't suitable for longer power outages.

 

[guymarshall]

That is exactly what many RAID controllers do. They have a battery to ensure that any data cached on the RAID card is written to disk or is protected on the card. Batteries work OK for short (hours) of power outage. But they aren't suitable for longer power outages.

What if the batteries are mounted on the actual RAM DIMMs, so one battery per RAM stick, and better battery life. What do you mean by the last 2 sentences?

 

[thx1138v2]

DRAM (Dynamic RAM) needs more than just power. If needs a refresh signal every so often, the rate at which it being refreshed controlled by the mobo and processor. So it's more complicated than just supplying battery power. Essentially what you are describing is sleep mode. Hibernate mode saves more power by saving the RAM contents and run time parameters to disk and then restoring it when waking from hibernate.

That's not exactly technically correct but close enough to compare to your question.

 

[guymarshall]

DRAM (Dynamic RAM) needs more than just power. If needs a refresh signal every so often, the rate at which it being refreshed controlled by the mobo and processor. So it's more complicated than just supplying battery power. Essentially what you are describing is sleep mode. Hibernate mode saves more power by saving the RAM contents and run time parameters to disk and then restoring it when waking from hibernate.

That's not exactly technically correct but close enough to compare to your question.

So can't they just add a 1 MHz CPU that generates no heat and needs little to no power and keeps the RAM refreshed? Or is it just not worth it?

 

[USAFRet]

Theoretically, yeah, you probably could.

Problems?
1. Don't let the battery die
2. Have a big wallet.

The circuitry needed is probably a bit more involved than "by just having a battery powering it"

I suppose the main problem is the fact that a 4TB HDD is £80, whereas 8GB of RAM is £80... And also yeah as you said, the battery must be quite beefy, but if all of those things are fixed, why don't companies do it?

Comparitively, RAM is still quite expensive.
128GB RAM = $2,000
128GB SSD = $60
1TB HDD = $50

As time progresses, things get cheaper. 1MB RAM was $100, and a 1TB hard drive was a choice between buying a house or buying a hard drive.

Even today, though...the lines between storage types are blurring. In a tablet, it's just chips on the motherboard.

Eventually, what you describe will be the norm. Not anytime soon, though.

 

[kyllien]

Non-volatile ram is call an SSD. The problem with it is that it is not fast enough. They are working on it though. But until they can get it to be as fast as volatile RAM it probably won't replace it.

You would be better off investing in a good uninterruptable power solution such as large batteries and a generator.

 

[USAFRet]

And for your concern about blocks wearing out on an SSD, that is mostly a non issue in normal use. Just about any current SSD will be obsolete simply due to size long before it wears out.

 

[nukemaster]

They actually had something like you are looking for, but it was years ago and had a low capacity and the battery only lasted a few hours for most users(On most systems the pci slots get power when off so this was more for power outs. A UPS would have been highly recommended).

http://www.gigabyte.com/products/product-page.aspx?pid=2180#ov

I was very close to getting some of these back then, honestly glad I did not because 8 gigabytes does not go far.

 

[guymarshall]

For some reason the website is being really slow, and it won't let me quote... So what about CPU cache? Will that be the next RAM or is it just too small and expensive?

 

[USAFRet]

So what about CPU cache? Will that be the next RAM or is it just too small and expensive?

Not really, because data sizes are also increasing.

A current CPU has 6MB cache. 3x the size of actual RAM in one of my first PC's.
On some of the larger HDD's, you can have a 128MB cache. Larger than one of the first hard drives I bought.

But what could you do with 128MB RAM (or hard drive) today? Not a lot.
There will always be some tiny, really really fast cache mechanism to speed things along.
But basically, the larger it gets, either price suffers, or speed suffers.
Large, fast, cheap - choose two.

 

[nukemaster]

You can always load up on more memory than you need and use a ramdrive.

Remember those have to be saved on shutdown(or at another interval) and loaded on startup(thus slowing those 2 operations). You will get the advantage of FAST read/writes with almost no access time, but will also want backup power because a power out will take out any non saved changes.

 

[guymarshall]

So what about CPU cache? Will that be the next RAM or is it just too small and expensive?

Not really, because data sizes are also increasing.

A current CPU has 6MB cache. 3x the size of actual RAM in one of my first PC's.
On some of the larger HDD's, you can have a 128MB cache. Larger than one of the first hard drives I bought.

But what could you do with 128MB RAM (or hard drive) today? Not a lot.
There will always be some tiny, really really fast cache mechanism to speed things along.
But basically, the larger it gets, either price suffers, or speed suffers.
Large, fast, cheap - choose two.

Yeah I guess so. 10 years ago, everybody was like "1MB of RAM is all you will need!", and now people moan when they have 8GB. Imagine a CPU with 1GB of cache!!

 

[reedo_43]

I actually got sucked in by the gigabyte i-ram for it's novelty. Yes it was bleeding edge and super fast but lack of storage killed it. I believe I kept 1 game, temp, temp internet files and pagefile on it. I ended up giving it away to a friend.

 

[jitpublisher]

For some reason the website is being really slow, and it won't let me quote... So what about CPU cache? Will that be the next RAM or is it just too small and expensive?

The main limiting factor in PC's today (contributing to memory types and configurations the average person can afford) affecting RAM speed is the motherboard. No matter how fast the memory stick is, its running off of a motherboard with a speed divider, of which the basic buss is still only 200mhz on modern boards! You can multiply, widen the buss, read and write at the same time, we have seen many memory advances for RAM, but you still have to crunch everything through that basic 200mhz buss speed. 1600mhz memory, 2400mhz memory, I mean, you reach a point where faster memory does not improve anything if you can't do something to improve the basic buss speed. Running a signal along all the trace ways and around corners on a motherboard has a huge, huge effect on high speed transmission. The problems associated here are not minor, using a board the size of a small dinner plate to move all this information at high speed is tricky business. One of the reasons CPU cache is so fast is because its sits directly on the die of the processor. This was done in steps, first cache was on the board just like RAM, then it moved closer to the cpu by mounting the cpu and cache on a daughter card which allowed the cache to run at half and later same speed as the processor. Remember the slot 1, slot 2 and slot A CPU's? And finally it was integrated into the processor. Who knows maybe someday what we know as RAM now will become obsolete in favor of a 128gig of cache memory.

But for now, they do have a type of non-volatile memory that works as an affordable solution for the current technology, whether mechanical or solid state, its called a hard drive.

 

[thx1138v2]

DRAM (Dynamic RAM) needs more than just power. If needs a refresh signal every so often, the rate at which it being refreshed controlled by the mobo and processor. So it's more complicated than just supplying battery power. Essentially what you are describing is sleep mode. Hibernate mode saves more power by saving the RAM contents and run time parameters to disk and then restoring it when waking from hibernate.

That's not exactly technically correct but close enough to compare to your question.

So can't they just add a 1 MHz CPU that generates no heat and needs little to no power and keeps the RAM refreshed? Or is it just not worth it?

With the OS providing the sleep and hibernate modes there is no incentive for motherboard manufacturers to add such functionality that would increase the price to the consumer. Let's say it cost $0.25 in parts but that would be times millions of units. For 1M units that would remove $250,000 from their bottom line. Then there is the cost of adding in BIOS support, user support, etc.

There's nothing to gain for them and the functionality is already there.