DRAM Almost as Fast as SRAM 115
An anonymous reader writes "IBM said it has been able to speed up the DRAM to the point where it's nearly as fast as SRAM, and that the result is a type of memory known as embedded DRAM, or eDRAM, that helps boost the performance of chips with multiple core calculating engines and is particularly suited for enabling the movement of graphics in gaming and other multimedia applications. DRAM will also continue to be used off the chip."
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Trust IBM (Score:5, Funny)
Yes, trust IBM. (Score:5, Insightful)
No, I'm not a fan of patent trolls; but this isn't patent trolling. IBM has created a new, better way to embed cache RAM on the CPU die, at a signifigant cost in both manpower and materiel. This isn't like they patented "a method to check customers out with one click" or something similarly banal. This is a real, new technology which took a great deal of time, energy and work to create. No "prior art", no "trivially obvious" - this is exactly the kind of technological advancement which patents should protect.
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Maybe they wouldn't cost millions if they outsourced the labour!
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Red herring.
People are unlikely to die because their DRAM is too slow. (Gamers are not people.)
The fact that we need to think hard about how to make life-saving drugs accessible while preserving an incentive to develop them has absolutely nothing to do with the obvious benefits of patenting this kind of expensive, innovative technology.
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I think I use to be like you, and I became very, very unhappy because of my attitude. Be a little more generous and patient. It will pay off.
Re: Yes, trust IBM. (Score:2)
And what do you put in its place? How do you indicate that you're not exaggerating or using hyperbole NOW?
Exactly. You can't (short of some clumsy phrase like 'and I'm not ex
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It costs money to develop drugs. LOTS of money. Money can be exchanged for goods and services.
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http://www.usatoday.com/news/health/2007-01-30-tha iland_x.htm [usatoday.com]
Even though the WTO was pre
What's the point? (Score:2, Insightful)
All chips wait at the same speed. Why not concentrate on the bottlenecks rather than what is already one of the fastest components in any system.
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Nuh uh! I guarantee my computer can do nothing a whole lot faster than yours can.
Re:What's the point? (Score:5, Insightful)
Firstly, system memory is not especially fast compared to the CPU, and the recent proliferation of multiple cores is making the situation worse because more CPUs are trying to bang on the same memory.
Secondly, the most straightforward way to paper over problems with high-latency devices is to put a cache in front of them. Super fast DRAM would be one way to enable bigger caches that reduce the impact of various system bottlenecks. Sure we can hope to replace all hard drives with solid state devices, but since they still cost orders of magnitude more per megabyte, it will probably be quite a while before that happens. In the mean time, better caches couldn't hurt.
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Intel's Core 2 Duo.
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CACHE MEASUREMENTS
MB to metric conversion table
40k = 1 centifuckton
64k = 1.6 centifucktons
400k = 1 decifuckton
640k = 1.6 decifucktons
1 MB = 2.5 decifucktons
1.44 MB = 3.6 decifucktons = 1 floppy
2 MB = 5.0 decifucktons
2.88 MB = 7.2 decifucktons =
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Intel's Core 2 Duo.
You may be surprised to know this, but the ratio of on-chip cache to typical system ram has not changed much in the last 12 years.
In 1995 I bought a mid-range 486 DX-2 50 computer. The chip had 4K cache on-die, and the system had 4MB ram (1/1024 ratio).
Today, you can buy a mid-range machine with 2-4MB on-die cache and 1024MB ram (either a 1/512 or 1/256 ratio). That's a tiny improvement, and that's to
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Re:What's the point? (Score:4, Informative)
Unless you want to pay $25 per GB [again...], I'd wait until things improve.
And it isn't like they're not working on smaller/faster memory. Two years ago a 1GB flash was 99$ [in Canada], now they're ~40$ and you can get a 2GB flash for about the price of the 1GB. I imagine this year we'll see 4GB flash drives become more of a norm, and so on.
Most likely, ten years from now 80GB flash drives will be common place enough and not super expensive. But until then, spinning platers!
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http://www.newegg.com/Product/Product.asp?Item=N82 E16820163159 [newegg.com]
http://www.newegg.com/Product/Product.asp?Item=N82 E16820220156 [newegg.com]
http://www.newegg.com/Product/ProductList.asp?N=20 03240522+1309421175&Submit=ENE&SubCategory=522 [newegg.com]
4GB flash for $40-$60, sd for $45, so $10-$15 per GB, right now. 1 GB cost $60 about 18 months ago(they are less than $15 now); extrapolate linearly, thats 64GB for cheap($60!) in 6 years, and 128+ in 8 years. That doesn't account for a slight depr
Redefining "Mass Storage" (Score:1)
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Also, FF 2.0 thinks cheapish is a word.
Re:What's the point? (Score:4, Interesting)
I expect to see 80GB flash drives long before 10 years. Assuming a growth rate of doubled capacity every 18 months, true enough, we'd reach about 80 GB in 10 years, but so far, flash memory has increased much faster than Moores law. Also I assume that the amount of data our computers manipulate continue to increase with each version of windows/HD-DVD/whatever, so we still need larger/slower storage mediums in 10 years, such as harddisks.
In fact, the whole idea of using a (set of) rotating platter(s) with magnetic coating and radially movable read/write head(s) for storage, has been so successful for so long, and continue to improve at such an astonishing rate, that I doubt it will go away any time soon. In the far future, it's more difficult to predict what would happen. But even today, wheels are important, fire is our main source of (non-food) energy, primitive cutting tools are regulary used in any household, and in general, assuming things fail to change, is rarely wrong (we still haven't got flying cars!)
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Sure we do. [youtube.com]
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"PQI, WHICH IS showing an engineering sample of a 64GB flash-based hard disk drive at Computex says the price for the expensive, but desirable, storage devices could fall below $1000 before the end of this year. "It depends on the chip price, but maybe it can get below $1000 this year" said Bob Chiu of PQI's Disk on Module sales dept. A competitor confirmed that such a precipitous fall in price was a possibility."
Because o
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Most likely, ten years from now 80GB flash drives will be common place enough and not super expensive. But until then, spinning platers!
But by then it wont matter. Windows Leasta will be out and require a Terabyte of install space and multiple terabytes to run, just for a jazzed up UI they licensed from someone else and vaporous claims of better security (this time) (we mean it) (really) (we promise) (but buy our Windows as long as you Live No Care, because you will need it).
:-)
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In comparison to the processor, is RAM not a bottleneck? An improvement in an area that has less need is still an improvement.
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They all run at similar temperatures.
The Cenatek RocketDrive you link to is a very dated product...it's not even bootable. Here is a more practical option:
http://www.gigabyte.com.tw/Products/Storage/Produc ts_Overview.aspx?ProductID=2180 [gigabyte.com.tw]
It's $115 at Newegg and holds up to 4 x 1G of 184 pin DDR.
4 gigs isn't much, but for certain situations, like holding a small database with heavy use, they work great. For random I/O, they are obscenely fast for the
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I actually am not involved with servers, and do little which requires fast processing - at least at home - so don't pay much attention to this market. I'm sure there are many options out there.
Re:What's the point? (Score:5, Insightful)
Yeah, but wouldn't it be better to buy a real computer with room for more RAM, so you didn't have to use a hardware device to imitate another hardware device, so that you could use software to imitate the drivers of the other hardware device, so that you could use it as the first kind of hardware device, just with lower speed and convenience? Or in other words: wouldn't it be better to just run the database in RAM?
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Yes... as long as there was a way to ensure data integrity in the event of an unexpected shtudown. The one nice thing about a journalled filesystem on a persistent store is that it doesn't go away when the lights go out...
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That does not operate on a battery. If you put - as the other poster suggested - a journalled filesystem on there (e.g. ZFS) then this device would not fail even on an unexpected shutdown, and there is little or no chance that it can be corrupted by the OS or another application. Unless the OS or the application mess with the filesystem of course. It's a bit of a shame that they don't allow more than 4 GB or ECC memory or hot swap, s
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One problem is that many of the companies have nothing to do with solid state storage, so they can do nothing a
On Striping Raptors (10k rpm SATA drives) (Score:1, Informative)
Better to have a single 10K Rappy (or better a piece of 15K SCSI/SAS goodness -- where are 15K SATA drives already???) as a "system/apps/work cache" and the
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Of course you can do the same for disks, but its much more costly to have the raid controller with the XOR engine and the typical huge cache sitting in front of it.
Also raids run rather slowly
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RAM speed is one of the biggest bottlenecks on your system. It's called a cache miss. When your CPU tries to access data outside its local cache, it has to wait for that cache line to come from system RAM. Your CPU currently spends a huge fraction of its execution time doing that. If IBM can provide a significantly faster type of system RAM, they can reduce that huge fraction, which would noticea
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This is how big corps make money - they keep improving the stuff the no-nothing wants and they make big bucks off minor 'improvements' that don't really help.
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Apart from the fact that...
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Hard drives aren't the bottleneck in certain applications so it's irrelevant to those.
Finally, why not improve the system everywhere it's possible? Why blow off CPU improvements only become some apps don't benefit?
Cheap Cache! (Score:1)
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SD-RAM (Score:1, Funny)
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Nah, not so much any more.
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That's why you put it in the computer instead.
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To those wondering (Score:5, Insightful)
However with DRAM it takes quite a bit of power just to keep data in memory (because of the constant "refreshes"), which isn't the case with SRAM. So this discovery wouldn't take SRAM out of production for applications which require its low power usage.
Re:To those wondering (Score:5, Informative)
Cache misses are expensive. Really expensive. There are two ways of getting around this:
- More hardware contexts so that you can switch to another thread instantly when a cache miss happens.
- More (SRAM) cache.
The first one is better if you have highly parallel software, but isn't so good for single-threaded applications. The second is the more common approach. While SRAM uses six transistors per bit, DRAM uses one transistor and one capacitor. This could give something around three times the density, allowing CPU manufacturers to triple the amount of cache without increasing die size. Bigger cache means fewer cache misses, which means less time spent doing nothing.For reference, a cache miss typically costs something around 1-200 cycles.
Great for L3 caches (Score:5, Interesting)
As for power concerns, DRAM is higher than SRAM, but a larger L3 cache may reduce the traffic through the memory controller, and out to the DIMMs, which will probably more than make up for any increase in power density in the cache.
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Good lord! I've always wondered what happend to those COAST [wikipedia.org] (Cache On A STick) modules back in the Pentium 1 days. Brings back memories...
Nah, CoaSt modules were the L2 cache, cause back then the CPU only had on-chip L1. PPro was the first to introduce on-die L2. P2 took a small step back by taking L2 back off the die, but leaving it on the cpu. Sun platforms and iirc Alpha (and probably a few others) used L3, but x86 did not. AMD just recently released info on their next cpu, which includes plans to implement an L3 that all CPUs can share. Makes sense when you think about it (L1 per core, L2 per cpu, L3 for all!). As for L2, most CPUs hav
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Tm
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If you get hold of a Pentium Pro, you can actually see both dies in the package.
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The power consumption of SRAM is actually increasing to the point where it doesn't offer any real benefits over DRAM. The problem arises from smaller transistors with greater leakage current. Older SRAM could sit there and draw almost no power - but no longer. Because SRAM requires more transistors then DRAM, the leakage current essentially offsets the power used during the refresh cycle on DRAM.
Now I'm not claiming that DRAM currently use
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Note that both IBM and Intel have recently announced new processes that provide reduced leakage currents.
No need to refresh? (Score:2)
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If each memory cell was a bucket and electric current was water DRAM would be a bunch of buckets with holes in them, with someone constantly running past them, checking whether they're above the half way mark, and refilling them if
xbox360 (Score:1)
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Source: eDRAM [wikipedia.org]
Most of them being IBM processors, and one MIPS. The news is not the development of eDRAM, but that IBM seems to be eager to replace SRAM with it in their processors.
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eDRAM is quite old (Score:4, Interesting)
Both the title and the summary are quite misleading, since eDRAM is on-chip and that of course is much faster than external off-chip memory, be SRAM, DRAM or whatever.
Some big examples? PS2, Nintendo Gamecube, Wii, Xbox 360. All these consoles use eDRAM for their GPU's on-chip framebuffers to enhance their performance, and that goes back to at least the year 2000 when the PS2 came out.
Some will be quick to say "no, the Nintendo consoles use 1T-SRAM, not DRAM". Yeah, right, but even 1T-SRAM (despite its name) is a form of embedded-DRAM.
Re:eDRAM is quite old (Score:5, Informative)
Second, the consoles that have issued PR about using "embedded DRAM" with their GPUs don't actually embed DRAM on the GPU die. The "embedded DRAM" is a process offered by NEC that is separate from the Sony and TSMC processes used to fab the GPUs that supposedly have "embedded DRAM." I am pretty sure that all of the consoles you mention include a separate custom DRAM chip in the same package as the GPU. I am certain this is the case for the XBox 360 [arstechnica.com]. I am unsure about Sony. That DRAM process substantially modifies the back end wiring to make room for a MIM cap between the FETs and the first level of metal.
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With small devices leakage is a problem, an
For those who don't know what the point is (Score:3, Interesting)
If you could stick a crapload of this on the Cell, then those SPEs could have more than 256kB memory each, and utilizing them would become dramatically easier.
I'd guess the next revision of Cell will have a shitload of eDRAM on it. And it will either have more SPEs, or a new bus that allows multiple Cells to be used. The latter would be more expensive to implement, but probably result in higher yields than substantially growing the Cell to support more coprocessors - the yields are already poor if they just turn all the SPEs on, or else why would they be disabling one?
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HTX ! (Score:2)
Just make them support HyperTransport.
And make them in BTX board. Or even better : make them Socket F/F+ and Socket AM2/2+/3 compatible and people will be able to drop them as vector accelerators in their existing multisocket motherboards.
(... hum, technically, that'll require making both the front-end bus HyperTransport *AND* the memory controller DDR (2/3) instead of current Rambus controller).
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Not just that, but it would be a bitchin' way to write a PS3 emulator :D
Here's a better explanation (Score:5, Informative)
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"The new design uses a three-transistor micro-sense amp that lets voltage current directly drive transistor gates."
voltage current?
Can we rephrase that in English? (Score:1)
Oh, good! They had me worried that I could no longer keep my DRAM in the water cooler. And how could I get through my day without a bit of chipless DRAM floating in midair above my keyboard?
Goodness. What next? They'll try to take away my off-chip flatware?
Not what I thought it would be (Score:1)
Another excuse to not drop the price of RAM (Score:2)
Sure, we'll get 3THz RAM, and it will be $150 for a 1GB stick. That's not what I want, nor what I expect. What I expect is that I get a 2GB stick for what was the price of a 1GB stick 12-18 months ago. By now 4GB sticks should be $75.
In the last couple years prices haven't dropped hardly at all and new stuff is no bigger than before. That doesn't happen in IT unless someone isn't playing fair. So who is it and how do we get them to stop?
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Only in cases where supply is constrained. If supply is not constrained, higher demand enables higher economies of scale. This is EC101 stuff.
Other upcoming types of RAM: Z-RAM and TTRAM (Score:4, Informative)
Z-RAM. One cell is a single transistor. Faster than SRAM, which uses 6 transistors per cell. http://en.wikipedia.org/wiki/ZRAM [wikipedia.org]
TTRAM. One cell contains 2 transistors. As fast as SRAM, according to Wikipedia. http://en.wikipedia.org/wiki/TTRAM [wikipedia.org]
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OBRAM (Score:2)
Special eDRAM (Score:1)
Still not close to ARAM (Score:2)
Flash Memory Price-Fixing Investigationr (Score:1)
Apparently, if you purchased a memory stick, or flash memory device you could be included if the investigation leads to a class-action suit.
The press release said go to www.hbsslaw.com for more information.