Princeton: Replacing RAM with Flash Can Save Massive Power

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If you where to run the PC for 8 hours a day it would cost any where from $200 - $250 a year so with that said here's $10 more and continue sucking up more juice for those SLI and CrossFire setups.
 
[citation][nom]PhoneyVirus[/nom]If you where to run the PC for 8 hours a day it would cost any where from $200 - $250 a year so with that said here's $10 more and continue sucking up more juice for those SLI and CrossFire setups.[/citation]

Different computers can use very different amounts of electricity and the cost of electricity can vary widely even within different parts of the same nation. I guarantee that some computers can cost far less than $200 a year and that some others can cost even more. Heck, some can cost over $200 in one person's home and maybe less than half that in anther person's home. Not only do the base prices per KWh change in different areas, but many places have tiered pricing, so the more power that one home uses, the more it costs per KWh. Besides, most people (even most gamers) don't have CFX/SLI setups.
 
[citation][nom]DRosencraft[/nom]I find the vitriol here from all these armchair researchers to be a little sad.[/citation]The pie in the sky claims tend to cause a lot of backlash. Even in a server enviroment this isn't night-and-day different from what they're already doing with Flash to complement memory and traditional storage. They're claiming they're removing bottlenecks, that's great. But it's software, not hardware. The real breakthroughs will come with newer hardware better suited to replacing/supplementing both RAM and Flash.

Also, they claim that they're lowering power requirements by some silly percentage. But even if true, that only happens if you replace huge amounts of memory with some seriously high-dollar Flash arrays. In a lot of cases, servers still need a certain amount of fast, reliable traditional memory. Whatever memory they are using right now, they need, and can't be replaced with something slower. So in those cases, it might replace whatever means by which they're already using Flash as cache. But it wouldn't actually be reducing the amount of RAM required.
 
[citation][nom]bloc97[/nom]YES!!! No more data loss due to power loss![/citation]

What gave you that idea? Once again, the RAM is not actually being replaced, but supplemented, so any RAM still in the system is no less volatile than without this technology.
 
This is a system for datacenter workloads where you really want large amounts of in-memory storage. Right now, that's not cost-effective beyond about 50-100GB per server using DRAM. This is where SSDAlloc comes in. It's aimed at workloads that you have to spread across multiple machines in order to meet cost requirements, and it allows you to consolidate to a smaller number of servers. The performance is much better than swap. See the paper or slides at
http://ssdalloc.cs.princeton.edu/technology.html
In particular, logical slide #21 shows the comparison vs swap for a number of apps
 
[citation][nom]sylvez[/nom]Princeton: Replacing Computer with Typewriter Can Save Massive Power[/citation]

Electronic typewriter's were mechanical - any time you screwed up you had to backspace and it used a ribbon to erase your mistake. That used a lot of energy. Modern computer chips use far less energy to input, store, and output data than did a typewriter. We had a Brother brand electronic typewriter when I was a kid, and the thing was a bit loud with a fan that blew just to keep the very basic/simplistic chip cool. (Keep in mind that all it could do was type). On top of that, it still had to move the parts.

Technically speaking, the PC when combined with a printer is a modern day typewriter.
 
Hi Trolls

did any of you read the paper @ http://ssdalloc.cs.princeton.edu/technology.html its mostly over my head but with some googlin seems far superior to SWAP.

I like the slide showing SWAP throughput at about 6000 reqs/second and ssdalloc at 45000 reqs/sec and it states that it uses %32 less write cycles... seems like an excellent server tech, and remember this is version 1.0 who knows where this will lead to.

Fungi
 
[citation][nom]haplo602[/nom]because they could not make headlines with that 🙂)[/citation]
ssd is slower when compared to RAM....sorry to bust your bubble....
 
[citation][nom]nebun[/nom]ssd is slower when compared to RAM....sorry to bust your bubble....[/citation]

SSDs can be made from system RAM and even faster memories, so SSD is obviously the wrong choice of terminology here and beyond that, NAND flash, the technology that you're undoubtedly referring to, doesn't need to be faster than RAM. This isn't about replacing RAM with it, this is about supplementing RAM with it.


Beyond that, an SSD can be made to be faster than system RAM in current computers even using NAND flash.

http://lenzfire.com/2012/01/ocz-launches-new-z-drive-r4-and-r5-pcie-ssd-ces-2012-2012/

Given an even faster interface, such as a PCIe 3.0 x32 slot, OCZ and Marvell could have designed an even faster SSD. Still, up to 2.52 million IOPS and up to 7.2GB/s sequential is quite fast and can beat some RAM interfaces. Two or four of them could be incredible.

As for what haplo602 said, it also had little to do with what you said. He/she didn't say anything about SSDs or RAM being faster than the other.
 
only issue is that flash memory is not designed for a RAM workload.

when programming most applications where RAM speed is not predicted to be a bottle neck, you don't worry about optimizing the code to reduce the number of IO's to the RAM.

Most programmers do not worry about it with modern applications because RAM is so fast that all they need to do is worry about keeping a small memory footprint but not worry about how many IO's they use.

If you put a non stop IO intensive workload on flash memory, even with SLC memory, it will kill it very quickly.

Also even the high end server SLC SSD's cant match the read and write speeds for RAM

A modern RAM stick can easily push read and write speeds of close to 20GB/s and they can offer that performance even with 4K reads and writes that cause SSD's to only offer a fraction of their speed.

If you have ever debugged a small, you will see that even a small basic game can write multiple GB and depending on how long you play, it can even write multiple TB in a relatively short amount of time.

also keep in mind that when comparing RAM speed, they can use any RAM that is in use today as their point of comparison then say "somewhat" slower.

meaning they can use DDR memory designed for ultra portable devices then anything close to around 500MB/s will be considered offering similar performance to RAM.
 
[citation][nom]Razor512[/nom]only issue is that flash memory is not designed for a RAM workload.when programming most applications where RAM speed is not predicted to be a bottle neck, you don't worry about optimizing the code to reduce the number of IO's to the RAM.Most programmers do not worry about it with modern applications because RAM is so fast that all they need to do is worry about keeping a small memory footprint but not worry about how many IO's they use.If you put a non stop IO intensive workload on flash memory, even with SLC memory, it will kill it very quickly.Also even the high end server SLC SSD's cant match the read and write speeds for RAMA modern RAM stick can easily push read and write speeds of close to 20GB/s and they can offer that performance even with 4K reads and writes that cause SSD's to only offer a fraction of their speed.If you have ever debugged a small, you will see that even a small basic game can write multiple GB and depending on how long you play, it can even write multiple TB in a relatively short amount of time.also keep in mind that when comparing RAM speed, they can use any RAM that is in use today as their point of comparison then say "somewhat" slower.meaning they can use DDR memory designed for ultra portable devices then anything close to around 500MB/s will be considered offering similar performance to RAM.[/citation]

http://www.tomshardware.com/reviews/ssd-710-enterprise-x25-e,3038-4.html

Intel's eMLC can take a lot more than you're giving it credit for and it isn't even actual SLC.

For a single stick of RAM to break 20GB/s, it would need to run at over 2500MT/s and that's obviously not going to happen in any server at least until DDR4 is out. Most servers today have memory running at 800MT/s, 1066MT/s, 1333MT/s, or 1600MT/s at the best; I don't think that any server has memory running at anywhere near 2500MT/s nor that many computers at all have such high frequency DDR3 DIMMs, granted there are undoubtedly a few. Regardless, that simply isn't normal.

Also, it would seem that you're acting as if you know all about this, but you almost certainly didn't even read the link that funguseater so kindly gave to us that explains the technology in a little more detail. The flash obviously isn't handling even most of the writes of the memory system.
 
Lots of discussion here came from the misleading title from TH. Many true; many speculative about the future but if you read the actual paper published is very clear :

IS A SOFTWARE ALGORITHM

Licensing it gives tools and support for a fast translation from byte addressing (SDRAM) into block adressing mode (FLASH) witch is different and faster than pure caching.
So far your only alternative was ignore that in you program and let the OS to handle the issue.Works but is optimization unfriendly. Besides is transparent if you want, just make you ram allocations as always.

Shure; flash memory densities put sdram to shame but today is too slow to be a serious contender.
But they complement each other beautifully.Nowhere in the paper suggest "REPLACING SDRAM with FLASH".
 
[citation][nom]blazorthon[/nom]SSDs can be made from system RAM and even faster memories, so SSD is obviously the wrong choice of terminology here and beyond that, NAND flash, the technology that you're undoubtedly referring to, doesn't need to be faster than RAM. This isn't about replacing RAM with it, this is about supplementing RAM with it.Beyond that, an SSD can be made to be faster than system RAM in current computers even using NAND flash.http://lenzfire.com/2012/01/ocz-la [...] 2012-2012/Given an even faster interface, such as a PCIe 3.0 x32 slot, OCZ and Marvell could have designed an even faster SSD. Still, up to 2.52 million IOPS and up to 7.2GB/s sequential is quite fast and can beat some RAM interfaces. Two or four of them could be incredible.As for what haplo602 said, it also had little to do with what you said. He/she didn't say anything about SSDs or RAM being faster than the other.[/citation]
i see your point, but at what price?...not everyone is a millionaire, lol
 
[citation][nom]nebun[/nom]i see your point, but at what price?...not everyone is a millionaire, lol[/citation]

Whether or not the average person can afford enterprise technology doesn't matter very much in this context because they aren't the target market.
 
[citation][nom]Pyree[/nom]And how much electricity would it save for an average personal computer? I doubt that is something an average PC user have to worry about.[/citation]
Actually RAM uses more power than one might think.... Just remember that the average PC user also doesn't overclock or play games at enthuasiest settings like the folks at Toms do... I think you could save a substantial amount of power over a reletively short period of time when viewed on a larger scale (eg,servers,clusters,supercomputers,labs,workstations....)
 
why not just a ssd that is made of RAM and a small battery like a cmos battery?
ram is faster.. and does not have the same limitations on write cycles as flash memory has.
i vote for ram based hardrives

i remember back when ssd's were not available, i searched for google for ram hardrive.. and saw pictures of a box that fit in a cdrom drive slot on a computer which you could put load sticks of ram into for fast data transfers through IDE ribbon cable.. it was expensive at the time, and i think i remember it useing pc 100 or ddr type ram.. but it still sounds like the way to go. running low on space?? buy a few sticks of ram and slap em in there... simple.
 
[citation][nom]aidynphoenix[/nom]why not just a ssd that is made of RAM and a small battery like a cmos battery?ram is faster.. and does not have the same limitations on write cycles as flash memory has. i vote for ram based hardrivesi remember back when ssd's were not available, i searched for google for ram hardrive.. and saw pictures of a box that fit in a cdrom drive slot on a computer which you could put load sticks of ram into for fast data transfers through IDE ribbon cable.. it was expensive at the time, and i think i remember it useing pc 100 or ddr type ram.. but it still sounds like the way to go. running low on space?? buy a few sticks of ram and slap em in there... simple.[/citation]

DDR3, the cheapest memory per GB, can get you 8GiB for $40-$50 and 16GB for $70-100 (with lower frequency modules). For the same prices, you can get several times more NAND fkash memory. Then there's the fact that no currently common consumer interface could use nearly the full performance of a RAM SSD.

Only PCIe could get even close to using two module's worth of it and even then, like I said, the huge price per GB even compared to SSDs is still a massive hurdle. Most people don't want an SSD that is smaller than even 90GB, but that would cost hundreds of dollars if it was made out of DDR3 SDRAM. Furthermore, it's not a RAM hard drive. Hard drive is just short terms for hard disk drive and I don't think that I need to explain what that is.

Beyond all of that, two major aspects of the technology in this article are decreasing power consumption and increasing capacity for the money of memory systems. A RAM drive system would negate both of those.
 
[citation][nom]hector2[/nom]I bet turning off the computer saves even more power[/citation]
yea just shut off that computer and use your imagination!
 
The power this would save a user is little because not only are you powering the flash ram but also the controller chip. In a server inviroment this thing would be dead in a month as flash ram only has a limited number of read right's. It's more cost effective to just get more RAM then to use this and have to replace this every so often.
 
[citation][nom]billgatez[/nom]The power this would save a user is little because not only are you powering the flash ram but also the controller chip. In a server inviroment this thing would be dead in a month as flash ram only has a limited number of read right's. It's more cost effective to just get more RAM then to use this and have to replace this every so often.[/citation]

The flash would not need to be replaced often, if at all during a server/super computer's lifetime if it is SLC and the flash (even with a controller included in this) uses much less power than RAM does, especially for reads, although writes ( it's writes, not rights, the two aren't even similar in meaning) still use less power than RAM. Look at a Samsung 830 SSD... For the top model, 512GB if I remember correctly (at least 256GB), it maxes out at 0.15w at load.

A single RAM module uses something like several dozen times that to maybe even several hundred times that with some of the top server RAM modules. The average person would not see a significant power usage decrease from this simply because the average person does not have a lot of RAM. I'm also fairly sure that consumers usually pay less than businesses do for the same amount of electricity, at least in the USA, so they have both higher RAM power consumption and higher cost per unit of electricity to consider in their bills.

Also, look up Tom's review of the Intel 710 SSDs. They can write a huge amount more data per cell than even Intel's MLC SSDs and those 710s are still using just a variant of MLC, so they might not be able to reach similarly high-end SLC in write tolerance. The flash for this technology would only need to be replaced if the company doesn't make sure that they have enough of it when they first buy it and that would be quite irresponsible of the people handling their upgrade.
 
[citation][nom]SmaugTD[/nom]Replacing your optical drive with a floppy drive can save massive power.[/citation]

I'm not even going to bother explaining how and why this is stupid because simply reading some of the previous comments will explain this.
 
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