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back to article DDR 4 sets the pace for fast memory

Reducing the size of chips has benefits beyond those seen in CPUs and GPUs. One other key component to gain an advantage is memory. The specification of the next generation of memory module, DDR 4 (DDR stands for 'double data rate'), is currently being finalised ahead of its anticipated launch later this year. It will use less …

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Silver badge
Joke

Sir

"low-power memory is important for desktop and laptop computers, it is crucial for servers."

I take it that wasn't deliberate!

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Anonymous Coward

Really faster?

IIRC when DDR3 PC DIMMs arrived, in reality they weren't faster than DDR2.

This was due to the longer timing clock cycles/latency required.

Lower power consumption was the main benefit.

I am guessing, same with DDR4 compared to DDR3.

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Meh

The extra memory bandwidth is surely very important for higher performance APUs, so I expect AMD will be investigating using DDR4 seriously.

However the change in topology surely makes it difficult to create a DDR3/DDR4 compatible memory controller to ease the transition, and the cost of DDR4 will be high upon release compared to DDR3.

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Holmes

Telling that Samsung's own example is a laptop...

For most performance-oriented laptops available now, there are two DIMM slots, each on their own memory channel, so the motherboard already has roughly as many wires running from the processor socket to the DIMM slots as would be needed for DDR4. Getting more bandwidth and better power usage for laptops is a pretty clear win.

This is not such a clear win for higher end desktop or server boards which currently run multiple DIMMs per channel. Remember that one of the selling points for FBDIMM was supposed to be that fewer wires per channel meant it was possible to fit more memory channels onto a motherboard at the same price point. More layers to fit more wires == more expense. Other factors weighed against FBDIMM more than this advantage, so it's unlikely to resurface... but the economics of cramming wires onto boards are largely unchanged.

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Anonymous Coward

speeds up to 3.2Gb/s

ah, up to again. Up to 3.2, but on average - 1.5. Maybe. With the "optimized" hardware. Every third day of every fourth month. See our full table of T&Ts, p. 1014 - 1932 for accurate measurements.

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Re: speeds up to 3.2Gb/s

Agreed.

You'd think from a PR perspective they should just announce exactly what it does now, then make announcements when the newer generation products are close to market.

Baffling PR logic, but then it is IT after all.

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Anonymous Coward

Re: speeds up to 3.2Gb/s

Samsung are only saying that the maximum speed of the first DDR4 modules will be 3.2Gb/s as opposed to the 4.266Gb/s the specification allows for.

As for the speed you actually get, put them into a board that is only capable of, say, 2.0Gb/s and that is the speed you will get. You may as well complain that the petrol you put into your Ford Ka doesn't go as fast as the petrol you put into your Bugatti Veyron (although I dont know why you would use a Ka when you have a Veyron).

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Bronze badge

AMD

AMD could get themselves some much needed income if they decided to jump on this bandwagon early...

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Re: AMD

I don't think AMD have any idea what a wagon even looks like, they've been jumping into empty stables for years now.

*remembers socket 939* sad that it has been that long since AMD were fully competitive.

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And they'll probably still get sued by Rambus.

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M 6
FAIL

Less Power? Really?

I would have accepted this until the downside was mentioned...all slots needs to be filled. OK, not a problem is you have a server maxed out on memory but if this is not the case then power consumption is going to go up.

Lets say there are eight memory slots in the server and four are used up. 8GB in each slot, 1.5v per DIMM. That's 6v. With DDR4, this will use 9.6v whatever the capacity you choose.

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WTF?

Re: Less Power? Really?

M 6: You're trolling right? You doknow that is not how electricity works?

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Anonymous Coward

Re: Less Power? Really?

@Tom 38: His statement is incorrectly put but I believe his premise is correct - when voltage isn't additive then current is and vice versa. The system will use more power if you assume both types of board use the same current. 1.5 x I x 4 against 1.2 x I x 8 gives 6 x I versus 9.6 x I (and I wish this was a different font). Hence, to get the benefit of the system you can end up using more power unless you fill the memory to capacity.

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M 6

Feel free to correct me, no need to be condescending

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Silver badge

Not much need ...

... to correct you either, because you were almost right - certainly close enough to make the point.

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it hurts

One of the consequences of knowing the diference between Volts, Amps and Watts is the painful twinge you feel when they are misused in conversation or reporting. The pain is felt quite often and I suggest it is even worse than the pain others feel from the whole there, their, they're problem.

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Meh

"One of the consequences of a point-to-point design is that every DIMM slot needs to be filled to maximise performance."

Does this mean the return of the 0MB stick that we used to need in days gone by for rimbus?

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Headmaster

@Lockwood

No, it doesn't mean the 0Mb stick will return. What it does mean is this...

The CPU's memory controller will have X number of pathways running to one of the chips on the DIMM module, kinda like PCI-e lanes, each lane can transfer data from it's chip simultaneously. When you leave a socket unpopulated, the memory controller will have unused pathways sitting idle, lowering the transfer rate, reducing memory bandwidth.

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Re: @Lockwood

Aha!

So, it needs them to be filled to work at the plated speed, rather than needing them to work at all?

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Re: @Lockwood

Yep, pretty much

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Happy

Well the one main benefit of....

....going to DDR2 then 3 and now 4 has just meant that messing around buying Turbo Nutter Mega Ram sticks with 'super low timings' has become largely a waste of time and money.

Just buy the good standard Crucial/Corsair/Kingston stuff and get on with your life.

If you have to buy fancy then just choose which heat spreaders look best with your motherboard.

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Anonymous Coward

Re: Well the one main benefit of....

this memory is that if you have to fill all the slots and then, when you want to increase memory... do you have to buy all new?

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Bronze badge
FAIL

Picture = Fail

Don't hold memory like that >_<

Unless of course you are wearing one of those anti static straps

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Re: Picture = Fail

My fellow engineers and I have postulated that boards are immune to ESD as long as the source of the ESD is the person who designed the board. Maybe they designed it.

Also nothing bad can happen to you as long as you are wearing an ESD wrist band. (plugged into ground or not)

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Devil

Re: Picture = Fail

Unless the BOFH uses it as a trip device or the PFY strangles someone with it.

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Anonymous Coward

No rush to DDR4

It's not likely many will be rushing to DDR4 as it will be pricey and only of value for server use. A typical DDR3 DIMM only uses ~10w so lower power is good, but let's not get carried away with what it means in the big scheme of life.

Desktop PCs have no need for DDR4 as DDR3 is not saturated and still has plenty of available bandwidth to be used. The need to populate ALL DIMM slots is a serious negative for DDR4.

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Re: No rush to DDR4

"The need to populate ALL DIMM slots is a serious negative for DDR4."

See, I thought the same thing to start with. I remembered the bad old days when, if upgrading your PC RAM, you had to buy matching pairs which often worked out VERY expensive. If you had a mother board with two pairs of slots and one pair had 2 X 512MB DIMMS to give 1GB of RAM you couldn't just buy another 512MB DIMM. You had to buy two thereby doubling the cost.

But, with the PC becoming more and more of a consumer product I'm not sure that matters any more. Yes, there will still be the enthusiast market for whom it will be an added expense. But then, when speccing a high-end gaming rig or video editing machine you expect expense.

The vast majority of people now buy laptops, tablets or all-in-one PCs which either can't be upgraded or just won't be. And I can't remember the last time we added RAM to a PC at work. It used to be a regular occurance but, with Windows 7 (and 8) having the same memory requirements as Vista, RAM hasn't really been an issue for the last several years.

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Anonymous Coward

Re: No rush to DDR4

If there was a need or even some value in DDR4 for desktop use, then maybe people would be willing to pay a premium for it, but there is none. In a laptop where power consumption is a concern, there is still little advantage to DDR4 as DDR3 LV can do the job for a lot less money and with excellent battery life. So servers are the only place where enterprise might sign up for more expensive DDR4 and the only place it is really of any practical value.

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FAIL

What's the maximum size of a DDR 4 module?

Paragraph after paragraph about DDR 4, but not a single word about the maximum memory size of a DDR 4 module! The photo in the article shows only a 2GB DDR 4 (not exactly impressive, since 4GB DDR 3 sticks have been around for ages) and I was hoping that we'd see 8GB DDR 4 modules as common as 4GB DDR 3 (yes, there are 8GB DDR 3 modules, but they're actually moderately rare) and maybe even 16GB DDR 4 modules?

It seems bizarre to me to raise the specs of everything in DDR 4 compared to DDR 3 and yet we're completely in the dark as to the maximum size of DDR 4 modules.

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Anonymous Coward

Re: What's the maximum size of a DDR 4 module?

Most people have no need for more than 4-8 GB. of RAM for a desktop. Servers obviously can use all the RAM they can get and since DDR4 is designed primarily for server use I'd expect 8 GB. DIMMs to be the norm and 16 GB. DIMMs to be an expensive upgrade.

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Hi, only 2Gb/s is the top end of current memory? Doesn't that mean that 3Gb/s Sata2 and 6Gb/s Sata3 etc is all a pointless (presuming you've got raid 1 SSDs connected to it so you can actually pump that kind of data speed) waist of time since it can't get the data into memory due to memory bottlenecks?

How can 10Gb/s ethernet work if we can't physically get data out of memory that fast? Can someone get me up to speed. Ta

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This post has been deleted by its author

2Gb/sec is per bit line - consumer processors have two 64-bit memory channels, so 2Gb/sec per bit line works out to 32GB/sec. Plenty of bandwidth for 10Gb cards - but whether the OS, drivers and application software can keep up is another question. :-)

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Anonymous Coward

Wide IO is the place to be today....

the reason they are slow to uptake this is clear why have 2Gb/sec with higher power DDR4 when you can have 100Gb/s and up to 2 Tb/s or 250 GB/s bandwidth in the near future with Wide IO2 512 bit 4x128 stacked DDR3 modules that's four parallel, independent, 128-bit memory channels ;)

uk so the first Wide IO isn't as fast initially at only up to 17GBps operating at 200MHz for a massive power saving in comparison but its JEDEC ratified and their also lookin gto ratify version two soon too, all bets are off for DDR4 Wide IO is the plcae to be now and in the near future, the PR people will just have to call it DDR Wide IO or something and pretend its DDR4 ;)

http://eda360insider.wordpress.com/2011/12/14/3d-week-wide-io-sdram-network-on-chip-multicore-tsv-asynchronous-logic-3d-soc-stack-from-cea-leti-and-st-ericsson-hits-all-the-advanced-notes-can-you-say-tour-de-force/

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