Does High-Speed DDR3 Help AMD's FX? Four 8 GB Kits, Reviewed

By Thomas Soderstrom
published

Rumor has it that fast DDR3 memory kits help uncork the performance of AMD's Bulldozer architecture. We grab four of the latest kits sporting data rates as high as 2800 MT/s with the goal of finding out. One contender rises to the top in this round-up.

G.Skill Ripjaws X F3-17000CL9D-8GBXM

An artifact of the war between DDR SDRAM and RDRAM, G.Skill still uses bandwidth (rather than data rate) in its memory model designations. The rest of the part number for these CL9, dual-channel, 8 GB Ripjaws X kits is almost self-explanatory.

CPU-Z often has trouble reading the SPD information from XMP-equipped modules on non-XMP-compatible motherboards, so we looked to the motherboard itself to see how all of today’s modules are programmed. Officially rated for up to DDR3-2133, these modules sport an aggressive (for the data rate) CAS 9 timing paired with far more moderate 11-cycle RAS-to-CAS delay. Users unable to reach DDR3-2133 with their platforms will also find handy DDR3-2000 CAS 8 settings.

Anyone not willing to manually configure their RAM ends up stuck with super-slow DDR3-1600 CAS 11 performance, since the rated specifications for all non-standard RAM requires overclocking tricks. We would have preferred to see the kit default to DDR3-1600 CAS 9, though G.Skill may have experienced support issues on previous models that included tighter timings.

Available for as little as $70, this pair of 4 GB modules comes with G.Skill’s limited lifetime warranty.

Thomas Soderstrom
Thomas Soderstrom
Thomas Soderstrom is a Senior Staff Editor at Tom's Hardware US. He tests and reviews cases, cooling, memory and motherboards.
65 Comments Comment from the forums
  • Rockdpm
    Interesting!. Still would wait for Pile driver. But since i do have a Kingston 8GB kit and a Sabertooth 990FX... may just have to try it one day
    Reply
  • jdwii
    Great article this proves a lot of rumors!

    People can finally stop saying how unfair it is to test Amd with slower ram when it supports higher speed ram even though higher speed ram cost more money. It would actually be unfair to Intel its not their fault Amd needs higher speeds to compete(which it doesn't) with Intel's 1333 ram controller.

    Ram speeds do how ever make a big difference on APU's.
    Reply
  • mayankleoboy1
    would love to see the same review for Ivy Bridge processors with and without iGPU HD4000.

    and do include more tests in the review.
    Reply
  • sarinaide
    More of the cheap stuff is my mantra.
    Reply
  • Crashman
    sarinaideMore of the cheap stuff is my mantra.Yeh yeh, but I really can't complain about paying $70 for 8GB of DDR3-2133, especially when it overclocks like that.
    Reply
  • Reynod
    AMD has enjoyed the performance benefits of an integrated memory controller for more than twice as long as Intel. And yet, it seems that Intel sets today's standard for acceptability.

    Replace the last word with "performance" crash.

    Good article which gets answers a couple of questions people have been asking - well done !!

    :)
    Reply
  • jaquith
    Thomas thanks for the review.

    First note:
    *KHX2400C11D3K4/8GX - is a Quad Channel kit specifically designed for the X79 ; link http://www.kingston.com/us/company/press?pagename=n1111c&year=2011&prLanguage=english_emea
    *WQ213UB4G vs WQ213UX16G (kit) - is ONE stick of RAM (not a matched kit) and its 'kit version' is Quad Channel kit specifically designed for the X79 ; link http://www.supertalent.com/datasheets/WQ213UX16G.pdf

    After that it makes sense that those (2) "kits" (in one case 4 individual sticks) failed @ Rated, and I wasn't interested in researching the others. I've seen other more in-depth testing on the AMD FX-8150 indicating that overall there's a slight advantage for the DDR3-1866 kits on a most of the AMD FX processors. Though @ 4AM 'to me' I'll edit this post after a few cups of coffee.

    The 'ideal' AMD kits have JEDEC 'SPD' @ Rated 'cloned' (XMP) encoding which is optimized for AMD and sometimes slightly different so you're not 'stuck' as you put it @ DDR3-1333. Those are the better KITS to test on the AMD FX lines.
    Reply
  • SteelCity1981
    Ram sppeds on a Bulldozer CPU means little and this just proves that so it doesn't matter if you are using DDR3 1600 ram or buying high performance RAM that can overclock to DDR3 2800 your not really seeing hardly any improvement with Bulldozer by doing so.
    Reply
  • bartholomew
    Good article, very informative!
    Thanks :)
    Reply
  • RAM speed also has a HUGE impact in controlled cache environments:
    http://thessdreview.com/our-reviews/romex-fancycache-review-ssd-performance-at-13gbs-and-765000-iops-in-60-seconds-flat/

    Even the best SSDs can barely muster 100,000 IOPs, yet even slow RAM can easily exceed 700,000 IOPs.
    Bandwidth, throughput, and latency are equally insane. RAM puts SSDs to shame exponentially more than SSDs put hard drives to shame. Contrary to what many "enthusiasts" believe, RAM timings are virtually irrelevant. Frequency is by far, much more important.
    Reply