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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  • menting - Friday, February 6, 2015 - link

    simulation software, pattern recognition, anything that does a lot of data analysis and/or data transformation. Heck, whatever an SSD's BW is good for, high BW memory can also be good for
  • retrospooty - Sunday, February 8, 2015 - link

    Simulation and pat rec maybe, not that anyone uses it other than rare outliers... But Anything an SSD is good for? No, not at all. An SSD improves launch times for anything and everything from browsers to office apps, to graphic suite apps like Adobe CS to games. Everything that normal people do. HB ram improves almost zero for the vast majority of what people actually do with computers. Even what enthusiasts do.
  • menting - Monday, February 9, 2015 - link

    "SSD improves launch times for anything and everything from browsers to office apps, to graphic suite apps like Adobe CS to games. Everything that normal people do". Exactly my point. Everything that normal people do. All that an SSD does is to provide faster storage (granted, it's non-dynamic storage, unlike DRAM) such that when a CPU can't find the data in the cache nor the DRAM, it can go to it for data. If you have enough DRAM, all these software can reside in DRAM (provided that power does not go out). Also, a smart algorithm will know what software you used before so it will keep some parts in memory so the next time you launch it it will be faster. And the speed that it can relaunch will heavily depend on DRAM BW.
    If you want to talk about rare outliers, people who are serious enough Adobe users or gamers who really get affected in a major way by using a SSD vs a traditional HD are rare outliers. I won't be surprised if the number of those people are on par or lower than people that use simulation software or pattern recognition software.
    BTW, if memory BW doesn't make much of a difference, why do graphic cards go for GDDRx instead of plain DDRx?
  • retrospooty - Monday, February 9, 2015 - link

    "BTW, if memory BW doesn't make much of a difference, why do graphic cards go for GDDRx instead of plain DDRx?"

    You are seriously clouding the issue here. With a graphics card assuming you are utilizing it with a modern 3d game or such, would benefit immensely from memory bandwidth on the card... It hardly benefits at all from system RAM bandwidth. Like everything, memory bandwidth doubling while timing/latency more than doubles doesn't improve system performance much at all. Some cases ahve it diminishing performance. This is NOT about Video RAM, its system RAM and based on the Intel CPU architecture for the past 15+ years, improving memory bandwidth at the cost of latency doesn't help much...

    AGAIN, as I said in my original post - "We saw almost no improvement going from DDR400 cas2 to DDR3-1600 CAS10 now the same to DDR4 3000+ CAS [rediculous]
  • menting - Tuesday, February 10, 2015 - link

    if you just want to talk about system RAM, the biggest blame is on software and CPU architecture, since with the exception of a few, are not optimized to take advantage of BW, only latency, even when the usage condition is ripe for doing so.
  • retrospooty - Wednesday, February 11, 2015 - link

    This is an article about system RAM. Why would anyone be talking about video RAM? Agreed, it is a CPU architecture issue, however this is the world we live in and this is the CPU architecture we have... Intel is pretty much the top of the heap.
  • FlushedBubblyJock - Sunday, February 15, 2015 - link

    Don't worry there are endless thousands of bonerheads who cannot wait to be "sporting" DDR4.
    For most, if they are made to think it should be faster, it is, no matter what occurs in reality.
    I'd say 75% of it is how happy hyped their mental attitude is about how awesome their new bonerhead equipment is marketed to be, including any errors and rumors about what it is they actually purchased and installed, which they in many cases are not clear on.
  • xTRICKYxx - Thursday, February 5, 2015 - link

    This would be an interesting topic to return to when DDR4 becomes mainstream with higher speeds.
  • WaitingForNehalem - Thursday, February 5, 2015 - link

    Now this is an excellent article. Thank you!
  • ExarKun333 - Thursday, February 5, 2015 - link

    AMAZING article! Been waiting for this! :)

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