Conclusions on Haswell-E DDR4 Scaling

When we first start testing for a piece, it is very important to keep an open mind and not presuppose any end-results. Ideally we would go double blind, but in the tech review industry that is not always possible. We knew the results from our DDR3 testing showing that outside of integrated graphics, there are a few edge cases where upgrading to faster memory makes sense but avoiding the trap of low base memory can actually have an overall impact on the system - as long as XMP is enabled of course. 

Because Haswell-E does not have any form of integrated graphics, the results today are fairly muted. In some ways they mirror the results we saw on DDR3, but are more indicative of the faster frequency memory at hand.

For the most part, the base advice is: aim for DDR4-2400 CL15 or better.

DDR4-2133 CL15, which has a performance index of 142, has a few benchmarks where it comes out up to 3-10% slower than the rest of the field. Cases in point include video conversion (Handbrake at 4K60), fluid dynamics, complex web code and minimum frame rates on certain games.

For professional users, we saw a number of benefits moving to the higher memory ranges, although for only very minor performance gains. Cinebench R15 gave 2%, 7-zip gave 2% and our fluid dynamics Linux benchmark was up +4.3%. The only true benchmark where 2800+ memory made a significant difference was in Redis, which is a scalable database memory-key store benchmark. Only users with specific needs would need to consider this.

There is one other group of individuals where super-high frequency memory on Haswell-E makes sense – the sub-zero overclockers. For these people, relying on the best synthetic test results can mean the difference between #5 and #20 in the world rankings. The only issue here is that these individuals or teams are often seeded the best memory already. This relegates high end memory sales to system integrators who can sell it at a premium.

Personally, DDR4 offers three elements of interest. Firstly is the design, and finding good looking memory to match a system that you might want to show off can be a critical element when looking at components. Second is density, and given that Haswell-E currently supports four memory channels at two modules per channel, if we get a whiff of 16GB modules it could be a boon for high memory capactiy prosumers. The third element to the equation is integrated graphics, where the need for faster memory can actually greatly improve performance. Unfortunately we will have to wait for the industry to catch up on that one.

At this point in time, our DDR4 testing is not yet complete. Over the next couple of weeks, we will be reviewing these memory kits individually, comparing results, pricing, styling and overclockability for what it is worth. Our recent array of DDR4-3400 news from Corsair and G.Skill has also got some of the memory manufacturers interested in seeing even higher performance kits on the test bed, so we are looking forward to that. I also need to contact Mushkin and Kingston and see if those CL12/CL13 memory kits could pose a threat to the status quo. 
Edit: Mushkin actually emailed me this morning about getting some product for review.

We have a couple of updates for our testing suite in mind as well, particularly the gaming element and are waiting for new SSDs and GPUs to arrive before switching some of our game tests over to something more recent, perhaps at a higher resolution as well. When that happens, we will post some more numbers to digest.

 

The Future of DDR4
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  • Tunnah - Thursday, February 5, 2015 - link

    Solid data I can use to stop myself being impulsive and upgrading my rig, thank you!

    Every now and again I get upgrade pangs, trying to justify it with numbers, and this article does a great job of showing what I already know - my system is fine, an upgrade will only show results on paper.

    *Doffs cap*
  • HiTechObsessed - Thursday, February 5, 2015 - link

    Just further proof that faster (more expensive) RAM doesn't do anything for gaming. I laugh when people buy Dominator Platinums for 2x or even 3x the cost of regular Corsair or G Skill for solely gaming rigs.
  • FlushedBubblyJock - Sunday, February 15, 2015 - link

    Despair not, one must understand that inside that stupid thick skulll, and beneath that irritating idiot bragging because he's so stupid he doesn't know any better, the doofus is happy, because he is so thick and so easily parted with his less than adequate money supply.

    So bottom line is every time dummy sits down to game, his moron noggin gets all fired up and happy because ignorance in that case is bliss.
  • MrSpadge - Thursday, February 5, 2015 - link

    This calibration at boot slowing the process down 5-8s: can't the system save the proper values from the last boot and start optimization from this point on? Wouldn't those values change only slowly, e.g. when the module is aging or their amount is changed?
  • name99 - Thursday, February 5, 2015 - link

    I understand that the goal here is to test the PAIR of Haswell-E and DDR4.
    However, when it becomes practical, might I suggest that you try for a comparison of
    (easier) AMD and DDR-4
    (harder) one of the ARM server chips and DDR-4

    The reason I suggest this is that we all know that Intel, especially on Xeon, has the best cache+memory controller subsystem in the business, which, by design, means they're the least helped or hurt by changes to DIMM performance. Vendors whose memory subsystems are not as spectacular will likely see larger swings in performance, and it would be of interest to see how large those swings are (which, in a way, also tells us something about the gap between these vendors' memory subsystems and Intel).
  • MikeMurphy - Thursday, February 5, 2015 - link

    I'm flood that precise timings aren't built into the eeprom for each system to use. Why is XMP even necessary with DDR4??
  • davidthemaster30 - Thursday, February 5, 2015 - link

    I would have liked to see DDR3 clocked to 2133 15-15-15 (like the JEDEC DDR4 spec) vs DDR4 at the same speeds in single, dual, triple and quad channel to see scaling from DDR3 to DDR4 and from the # of channels. Also in the DDR3 vs DDR4 page, the specs for DDR4 are "DDR4-2133 14-14-14 350 2T" but I'm pretty sure that 350 is supposed to be 35 ... and the speed of the DDR3 for those tests is not stated.
  • Ranger101 - Friday, February 6, 2015 - link

    A very detailed, well written article, but for me, somewhat academic as
    the conclusion in comparative memory articles always seems to be the
    same."There are a few edge cases where upgrading to faster memory makes
    sense."
  • galta - Friday, February 6, 2015 - link

    Yes, because this is the only logical conclusion.
    Having said that, the community should probably stop discussing RAM, at least until we get to DDR9
  • menting - Friday, February 6, 2015 - link

    that means never discussing RAM again :)

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