Sunday, September 14th 2014

How Intel Plans to Transition Between DDR3 and DDR4 for the Mainstream

The transition between DDR2 and DDR3 system memory types was slower than the one between DDR and DDR2. DDR3 made its mainstream debut with Intel's X38 and P35 Express platforms, at a time when the memory controller was still within the domain of a motherboard chipset, at least in Intel's case. The P35 supported both DDR2 and DDR3 memory types, and motherboard manufacturers made high-end products based on each of the two memory types, with some even supporting both.

Higher module prices posed a real, and higher latencies, posed a less real set of drawbacks to the initial adoption of DDR3. Those, coupled with the limited system bus bandwidth, to take advantage of DDR3. DDR3 only really took off with Nehalem, Intel's first processor with an integrated memory controller (IMC). An IMC, again in Intel's case, meant that the CPU came with memory I/O pins, and could only support one memory type - DDR3. Since then, DDR3 proliferated to the mainstream. Will the story repeat itself during the transition between DDR3 and the new DDR4 memory introduced alongside Intel's Core i7 "Haswell-E" HEDT platform? Not exactly.

Intel wants to make real sure that the swelling inventories of DDR3 memory modules are sufficiently digested by the market (sold out), before imposing DDR4 onto the mainstream. Hence the memory made its grand client entrance with Core i7 "Haswell-E," a family of processors that starts at $390, going all the way up to $1000. The target audience of these chips won't mind spending the extra dime on cutting-edge technologies, including memory. "Haswell-E" features a 256-bit wide DDR4 IMC, which at JEDEC standard speeds of DDR4-2133 MHz, can bathe the processor's 6-8 cores in 68 GB/s of memory bandwidth, right off the bat. DDR4 brings energy efficiency to the table. DDR4-2133 MHz modules ship with rated voltage as low as 1.2V, compared to the 1.8V DDR3 debuted with, before dropping to 1.65V on Nehalem, and 1.5V on SandyBridge. These drops in module voltages were made possible with DRAM manufacturers shrinking their fab process nodes.

Intel's bright idea about transitioning between DDR3 and DDR4 for mainstream client platforms is not hugely different from how its P35 Express chipset dealt with the issue. It plans to come up with a new memory module form-factor, called UniDIMM. It's a DIMM that can hold both DDR3-class and DDR4-class DRAM chips, designed for Intel's upcoming Core "Skylake" processors. "Skylake" will feature an IMC that supports both DDR3 and DDR4. With UniDIMM at their disposal, system manufacturers can source UniDIMM modules with DDR3 DRAM chips (which will be cheap, until DDR3 inventories begin drying up), and offer upgrade potential to UniDIMMs with DDR4 chips (which will get progressively cheaper). Future notebooks that ship with DDR4-UniDIMM memory will still support older DDR3-UniDIMM.

Capiche? No? UniDIMM is a standardized module design, with its key cutout notch at a certain point. Measuring 69.6 mm x 20 mm, it's as wide, but shorter than an SO-DIMM. There will be two kinds of UniDIMMs, DDR3 UniDIMM and DDR4 UniDIMM, both having 260 pins, the same key position (but one that's different from DDR3 SO-DIMM), and hence work on a platform that supports both standards, "Skylake," in this case. The module will be designed to support both standard- and LP- DDR3 and DDR4 DRAM chips.

DDR3/LPDDR3 UniDIMMs will ship with frequencies of 1866 MHz (DDR) as standard. DDR4/LPDDR4 ones will start at 2666 MHz (Skylake's standard DDR4 memory clock speed, double that of DDR3-1333, which was Lynnfield's standard). There will be higher-tier standardized clocks, such as 2133 MHz for DDR3/LPDDR3, and 2933 MHz for DDR4/LPDDR4. Since UniDIMM is more of Intel's pet-project than that of JEDEC, it gets to announce which memory module makers have expressed interest in it - Kingston and Micron (makers of Crucial) have expressed commitment to it.

"Skylake" Core processors come out in 2015. That's going to be when DDR4 enters mainstream client platforms.
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25 Comments on How Intel Plans to Transition Between DDR3 and DDR4 for the Mainstream

#1
Steevo
So they plan on doing a AMD, where the IMC will support both, to please the retailers that still have a crap ton of DDR3, and the performance benefits of DDR4 are not there yet.


Their ideas on UniDIMM seems a bit retarded though, 1866 for DDR3 as default? Seems like a good way to get stuck with platform specific hardware much like RAMbus. How about giving us a riser card that fits a DDR4 slot that adapts to DDR3, or a board with both slots but only two of each? But that might be too simple, sounds like a dick move to force people who adopt to stay with their proprietary hardware or pay the price.
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#2
macintux
So, their plan on getting users to adopt the new DIMM standard is to invent their own DIMM standard?
That's utterly retarded.
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#3
newtekie1
Semi-Retired Folder
Awesome, so we'll have people trying to put DDR3 and DDR4 in at the same time and wondering why it won't work. Way to add to the confusion Intel.

Why not just stick with the standards and do what worked with 775 and AM3, let the board makers pick the RAM that will be used. Lower end boards will use DDR3 and high end boards will use DDR4. Since low to mid-range boards sell vastly higher quantities than the high-end boards, DDR3 will stay in demand to dry up the stock, then when the DDR3 supply is drying up board manufacturers can switch entirely to DDR4.
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#4
d1nky
newtekie1 said:
Awesome, so we'll have people trying to put DDR3 and DDR4 in at the same time and wondering why it won't work. Way to add to the confusion Intel.

Why not just stick with the standards and do what worked with 775 and AM3, let the board makers pick the RAM that will be used. Lower end boards will use DDR3 and high end boards will use DDR4. Since low to mid-range boards sell vastly higher quantities than the high-end boards, DDR3 will stay in demand to dry up the stock, then when the DDR3 supply is drying up board manufacturers can switch entirely to DDR4.
This makes a lot more sense!

It's easy to see that Intel pretty much controls the market and evolution of tech. when you see this!
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#5
starcraftuuu
Do I understand it correctly? Will this new uniDIMM be used only with Skylake and then abandoned?
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#6
FordGT90Concept
"I go fast!1!11!1!"
newtekie1 said:
Why not just stick with the standards and do what worked with 775 and AM3, let the board makers pick the RAM that will be used. Lower end boards will use DDR3 and high end boards will use DDR4. Since low to mid-range boards sell vastly higher quantities than the high-end boards, DDR3 will stay in demand to dry up the stock, then when the DDR3 supply is drying up board manufacturers can switch entirely to DDR4.
Because the memory controller moved from the north bridge to on-die. Via was the reason why DDR and DDR2 co-existed on the same board. Intel wants to do the same thing, at least initially.

To be honest, I don't like the idea. But I see their motivation and understand it.


starcraftuuu said:
Do I understand it correctly? Will this new uniDIMM be used only with Skylake and then abandoned?
That's the way I take it as. It allows DDR3 and DDR4 chips to be used on proprietary sticks. It smells of FB-DIMM (let's do something crazy for the sake of...something).

I presume post Skylake will have the same DDR4 standard X99 is using now. The reason why they are going back to the industry standard will be because it supports higher densities per stick.
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#7
newtekie1
Semi-Retired Folder
FordGT90Concept said:
Because the memory controller moved from the north bridge to on-die.
The memory controller was on-die when AM3 came out.
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#8
Frick
Fishfaced Nincompoop
I really loved the crazy boards Asrock made, so am all for confusing standards.

Bring back the CPU upgrade boards as well and I'll be in heaven.
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#9
LAN_deRf_HA
So their plan is of no help to consumers as they'd have to buy whole new DDR3 sticks anyways. I'd say making low height ram standard would be interesting for constricted ITX builds and clearance issues on big coolers but if the standard is temporary that's no help either. So this entire strategy is just to smooth out adoption of their new platforms with OEMs that have stock piles of DDR3 chips.

As a consumer I'd much rather they went with a different approach, like say giving people a big enough performance improvement to warrant switching platforms. Comparing where we are now to Sandy core for core it feels like we've just been inching along.
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#10
Aquinus
Resident Wat-man
newtekie1 said:
The memory controller was on-die when AM3 came out.
The board should support one or the other, the CPU should support both like AM3 (in my personal opinion). To support both on the same board is insane and I remember when ASRock used to do that. A unified DIMM design is a little too stupid because now your DIMMs might not work in other motherboards because of the DIMM itself but not the memory modules or the actual interface itself.
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#11
GhostRyder
newtekie1 said:
Awesome, so we'll have people trying to put DDR3 and DDR4 in at the same time and wondering why it won't work. Way to add to the confusion Intel.

Why not just stick with the standards and do what worked with 775 and AM3, let the board makers pick the RAM that will be used. Lower end boards will use DDR3 and high end boards will use DDR4. Since low to mid-range boards sell vastly higher quantities than the high-end boards, DDR3 will stay in demand to dry up the stock, then when the DDR3 supply is drying up board manufacturers can switch entirely to DDR4.
This is the better idea, I mean it will be a problem I have a feeling for many users.
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#12
HumanSmoke
LAN_deRf_HA said:
So their plan is of no help to consumers as they'd have to buy whole new DDR3 sticks anyways.
No, but it probably helps one of their biggest partners, Micron.

Intel business relationship >>>>>> consumer
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#13
The Von Matrices
Maybe I'm interpreting this incorrectly, but I don't see anywhere in the article where it states that UniDIMM is the only module type supported by Skylake. UniDIMM sounds like the way to please the Dells and HPs of the world, where they build millions of computers and the ability to swap memory easily based on cost is a big concern. However, the market for UniDIMM is going to be small even for those Dells and HPs since it is a DIMM form factor, so it can't be used in ultraportable laptops or tablets where the memory is soldered to the board to save z-height.

For the people who build their own systems, it doesn't sound like there is any reason not to expect that motherboard manufacturers will focus upon LGA1151 boards with conventional DDR3 and/or DDR4 DIMM slots. For the build-your-own market, UniDIMM seems like it will at best be a niche.
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#14
Jorge
For those who haven't done their DDR3 / 4 homework... DDR4 is designed primarily for servers. It offers no tangible system performance over DDR3 LV. In fact testing with real applications shows that there is no tangible system performance gains on CPU powered desktops above 1600 MHz. DDR3 RAM as this is not a system bottleneck. On APU powered systems DDR3 up to 2133 MHz. shows small gains. Any higher frequencies are a waste of money as is DDR4 for anything other than servers.
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#15
The Von Matrices
Jorge said:
For those who haven't done their DDR3 / 4 homework... DDR4 is designed primarily for servers. It offers no tangible system performance over DDR3 LV. In fact testing with real applications shows that there is no tangible system performance gains on CPU powered desktops above 1600 MHz. DDR3 RAM as this is not a system bottleneck. On APU powered systems DDR3 up to 2133 MHz. shows small gains. Any higher frequencies are a waste of money as is DDR4 for anything other than servers.
I guess you haven't done your homework, because Samsung shows a 37% decrease in memory power consumption by using DDR4 over DDR3L. That's more battery life in laptops and tablets. Definitely not a waste in a non-server environment.
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#16
remixedcat
This is worse then the wave 1 802.11ac stuff -_- way to go full retard.
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#17
sunweb
People don't want to upgrade new CPU because they'll have to upgrade also MB and Memory and all of that because of new memory standart. So Intel invents another memory standart that is also incompatible with todays solution and works on specific mobos that supports them, meaning people will still have to buy new memory modules and a new mobo.
Did i get it right?
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#18
Flanker
I guess it doesn't matter to me since I'll be building from scratch.

But still, wtf?

The Von Matrices said:
Maybe I'm interpreting this incorrectly, but I don't see anywhere in the article where it states that UniDIMM is the only module type supported by Skylake. UniDIMM sounds like the way to please the Dells and HPs of the world, where they build millions of computers and the ability to swap memory easily based on cost is a big concern. However, the market for UniDIMM is going to be small even for those Dells and HPs since it is a DIMM form factor, so it can't be used in ultraportable laptops or tablets where the memory is soldered to the board to save z-height.

For the people who build their own systems, it doesn't sound like there is any reason not to expect that motherboard manufacturers will focus upon LGA1151 boards with conventional DDR3 and/or DDR4 DIMM slots. For the build-your-own market, UniDIMM seems like it will at best be a niche.
Ah... if it turns out this way it would actually make sense.
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#19
Kisai
newtekie1 said:
Awesome, so we'll have people trying to put DDR3 and DDR4 in at the same time and wondering why it won't work. Way to add to the confusion Intel.

Why not just stick with the standards and do what worked with 775 and AM3, let the board makers pick the RAM that will be used. Lower end boards will use DDR3 and high end boards will use DDR4. Since low to mid-range boards sell vastly higher quantities than the high-end boards, DDR3 will stay in demand to dry up the stock, then when the DDR3 supply is drying up board manufacturers can switch entirely to DDR4.
If anyone remembers the i820 Memory Translator Hub debacle when Intel tried to push Rambus with the Pentium 4, they will know this is a horrible idea.

http://www.geek.com/chips/intel-motherboard-mess-564785/
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#20
Aquinus
Resident Wat-man
So you have a UniDIMM with DDR4 and you buy a real DDR4 motherboard, suddenly you need new DRAM. I think that's really dumb. Your memory is "compatible" but doesn't fit in the DIMM slot. That's damning.
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#21
remixedcat
and pointless... when you have to buy new DDR4 based stuff anyways.... WHAT THE FECK IS THE POINT??!!!
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#22
FordGT90Concept
"I go fast!1!11!1!"
All I know is that this puts a big damper on my Skylake hopes. This just made X99 many fold more appealing. I really, really, really hope Intel only does this on BGA Skylake chips. Leave LGA standard DDR4 DIMMs.
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#23
rtwjunkie
PC Gaming Enthusiast
I've noticed on Newegg that the supply of DDR3 is going down already. Whole models are not available anymore, and many others are limited to 5 per customer.
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#24
The Von Matrices
FordGT90Concept said:
All I know is that this puts a big damper on my Skylake hopes. This just made X99 many fold more appealing.
FordGT90Concept said:
Leave LGA standard DDR4 DIMMs.
I think you're mistaken about the concept. UniDIMM doesn't preclude the use of traditional DIMMs with the processor given the appropriate motherboard. Skylake has 3 DIMM options - DDR3-DIMM, DDR4-DIMM, and DDR3/4-UniDIMM. It's up to the motherboard manufacturer to choose which one(s) to implement.

OEMs like Dell will choose UniDIMM motherboards as it gives them the most flexibility in memory options. End users like you and me buying our own motherboards will choose ones with conventional DIMM slots since the DIMMs will be cheaper and either backwards compatible (DDR3-DIMM) or faster and more future proof (DDR4-DIMM).
FordGT90Concept said:
I really, really, really hope Intel only does this on BGA Skylake chips.
UniDIMMs aren't intended for BGA chips, as they're likely to be the ones that have the memory soldered to the motherboard anyway. Most likely you'll see UniDIMM in desktop PCs from OEMs only where changing out the DIMM based on available supply is desirable and the extra power consumption of DDR3 isn't an issue. You won't see them in laptops because they will switch to DDR4 immediately due to the power savings even if the memory chips are more expensive.
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#25
TheLostSwede
I know I'm late to the game, but I'm amazed that none of you noticed that this is a SODIMM form factor, i.e. for notebooks. It has nothing to do with desktops. :shadedshu:
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