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Six Low-Voltage Dual-Channel 8 GB Memory Kits, Overclocked

Six Low-Voltage Dual-Channel 8 GB Memory Kits, Overclocked
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We've abided by Intel's 1.55 V recommendation for two architectures and two die shrinks, yet most performance memory manufacturers ignore it. Recent problems with one of our builds raised the question, how far can we push RAM without killing CPUs?

Remember the Nehalem architecture? Intel’s now-historic adoption of a CPU-based DDR3 memory controller was accompanied by a warning that voltages beyond 1.65 V could fry the integrated circuitry over time, effectively killing the CPU. In those days, Intel was manufacturing its processors at 45 nm and tolerating core overclocks using 1.45 V settings. AMD was pushing far higher DDR3 voltage levels at the time, but the entire performance-oriented DRAM industry eventually adopted Intel’s 1.65 V limit.

We've since seen two die shrinks from Intel—the 32 nm Sandy Bridge and Ivy Bridge at 22 nm—with no official word from the company on what constitutes safe overclocking. Instead of commenting on the parameters you're safest sticking to, its representatives tend to quote motherboard manufacturing guidelines of 1.50 V, plus or minus 50 mV. And we thought those documents were made public expressly to help us perform pin-mods...

If Intel’s reluctance to discuss anything outside of manufacturing parameters doesn’t worry you, perhaps the covert over-voltage applied to enthusiast-class motherboards should. The industry’s dirty little secret in the days of Nehalem was a 5 to 10 mV default boost, needed to make certain poorly-programmed (Ed.: Gold-series) memory modules bootable. That extra voltage was not reported on the hardware monitoring pages of most motherboard BIOSes, and most monitoring apps failed to report it as well. 

Well, if a little is good, a little more is better, right?

While Intel was busy shrinking its feature widths by roughly half, motherboard manufacturers were on a quest for overclocking records. I watched boards reach ever-higher 1.65 V memory overclocks as covert voltage tweaking climbed to 35 mV. Viewing this as a form of cheating in our motherboard comparisons, I broke out the volt meter and began reporting the setting needed to reach 1.65 actual volts in the firmware pages of our motherboard round-ups. And speaking of breaking things, a recent string of bad luck suggests that combining the accepted standard of 1.65 V and transparent over-voltage from certain motherboard vendors might not always be safe. Although that was certainly an unusual chain of events for us, it was enough for us to reconsider Intel’s 1.55 V recommendation. Can any of today’s lower-voltage RAM deliver world-class performance without breaking past that limit?

Rated Specifications
 Data RateTimingsVoltageWarranty
Adata XPG DDR3L AXDU1600GC4G9-2GDDR3-1600 (XMP)9-9-9-241.35 VLifetime
Crucial Ballistix Tactical BLT2K4G3D1608ET3LX0DDR3-1600 (XMP)8-8-8-241.35 VLifetime
Geil Evo Leggera GEL38GB1333C9DCDDR3-1333 (SPD)9-9-9-241.50 VLifetime
G.Skill Sniper SR2 F3-12800CL9D-8GBSR2DDR3-1600 (XMP)9-9-9-241.25 VLifetime
Kingston HyperX KHX1600C9D3LK2/8GXDDR3-1600 (XMP)9-9-9-271.35 VLifetime
Super Talent W160UA4GMLDDR3-1600 (SPD)11-11-11-281.35 VFive Years


We invited every major manufacturer (including a crowd-favorite ODM) to this round-up, and a few (including that ODM) chose not to participate. Of those that chose to be included, one didn’t have anything to offer with a DDR3L rating. Geil responded to our 1.35 V and 1.50 V stated test settings with a hearty "we can do that on standard RAM", and the company is now getting a chance to prove it.

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  • 1 Hide
    excella1221 , May 12, 2013 9:34 PM
    Nice article.
    A bit surprised that Corsair Vengeance didn't make an appearance though.

    Been using G.Skill RAMs since I can remember, and they've never failed me!
  • 1 Hide
    DarkSable , May 12, 2013 9:54 PM
    Very interesting read, thanks Tom's! Guess we've been bothering you enough about, erm, "half-height" overclocker's ram enough for you to want to do an article on it. Shame that the mystery modules chose not to participate... perhaps I'll send you my 8 gigs. Want to swap? Ship me some ram to use in the mean-time and I'll ship you my sticks.
  • 8 Hide
    rmpumper , May 12, 2013 10:02 PM
    In other words, RAM speed is irrelevant if you are not using an APU.
  • -2 Hide
    Haserath , May 12, 2013 10:03 PM
    No power consumption numbers? :/ 
  • 8 Hide
    cobra5000 , May 12, 2013 10:43 PM
    Good testing but at the start of the article, much emphasis was placed on the degradation of the cpu due to high memory voltage and then it just turns into a memory speed test. What about the cpu degradation?
  • -2 Hide
    envy14tpe , May 12, 2013 11:12 PM
    Good article. Still left wondering why anyone would choose low voltage RAM when costs do not outweigh the benefits.
  • 2 Hide
    slomo4sho , May 12, 2013 11:20 PM
    It is only worthwhile to pickup low voltage ram if you can obtain it at the same price as 1.5v ram. Then again, the Ballistix is around the same price point as other similar timing ram.
  • -1 Hide
    allan_hm , May 13, 2013 12:49 AM
    Pointless analysis for too little performance AND price difference...
    Would be a bit less irrelevant if more brands were tested.
    To be honest I was more interested on that "dirty little secret" details than the test itself.
    Also, an article named "who is who in the RAM marked" would be awesome, just like that one about Power Supplies...
  • 0 Hide
    Crashman , May 13, 2013 2:08 AM
    excella1221Nice article.A bit surprised that Corsair Vengeance didn't make an appearance though.Been using G.Skill RAMs since I can remember, and they've never failed me!
    Here's from the article:
    Quote:
    We invited every major manufacturer (including a crowd-favorite ODM) to this round-up, and a few (including that ODM) chose not to participate.
    Corsair said they had some new modules coming out and didn't want to focus on older models.
    cobra5000Good testing but at the start of the article, much emphasis was placed on the degradation of the cpu due to high memory voltage and then it just turns into a memory speed test. What about the cpu degradation?
    What about it? It's never been seen at 1.50V.
  • 0 Hide
    Crashman , May 13, 2013 2:10 AM
    allan_hmPointless analysis for too little performance AND price difference...Would be a bit less irrelevant if more brands were tested.To be honest I was more interested on that "dirty little secret" details than the test itself.Also, an article named "who is who in the RAM marked" would be awesome, just like that one about Power Supplies...
    Article intent was to find modules within Intel's 1.55V limit that pulled top numbers in frequency and/or latency. Some were found, article is a success.
  • 1 Hide
    Onus , May 13, 2013 5:40 AM
    Comparing data within each chart was not as interesting to me as comparing data between charts, which once again showed that although differences exist, they are tiny.
    Put a lot more thought into your platform, CPU and graphics card; for RAM, get the cheapest DDR3-1600 CAS9 and call it a day.
  • 0 Hide
    JackNaylorPE , May 13, 2013 6:24 AM
    Anybody read Intel's web pages in this regard ?

    1.5 volts is for the JDEC profiles .... but most RAM speeds are advertised and labeled based upon their XMP profiles......most XMP profiles for i5 and i7 RAM is 1.65. In fact, over 2/3 of the RAM on Intel's XMP compatible list are over 1.50 volts.

    I have seen many posts saying "Well that's a MoBo manufacturer thing". No....Intel sets the XMP profile. I agree, Intel's JDEC specifications stipulate 1.5 volts .... for JDEC profiles ..... but XMP "allows compatible DDR3 memory to perform beyond standard specifications" and is "predefined and tested" by Intel

    http://www.intel.com/content/www/us/en/gaming/gaming-computers/intel-extreme-memory-profile-xmp.html

    Quote:
    Intel® Extreme Memory Profile (Intel® XMP) allows you to overclock compatible DDR3 memory to perform beyond standard specifications. It’s designed to enhance the gaming features built into Intel® technology–based PCs. If you like to overclock and squeeze as much performance from your PC as possible, then memory based on Intel XMP gives you that extra edge you need to dominate—without breaking a sweat.

    Predefined and tested Intel XMP profiles can be loaded via BIOS or a specific tuning application through a computer’s operating system. Often the easiest way to load Intel XMP profiles is using a tuning utility, which may be available depending on the particular board manufacturer. To learn whether a tuning utility is available on your system, you should contact the board manufacturer.


    Again, most listed compatible i5 / i7 RAM is 1.65 .... at least according to Intel's compatibility lists

    http://www.intel.com/content/www/us/en/gaming/gaming-computers/core-i5-processor-memory-datasheet.html
    http://www.intel.com/content/www/us/en/gaming/gaming-computers/core-i7-memory-suppliers-datasheet.html

    Intel's approved i7 Compatibilty List (April 2012) includes:

    34 1.65 volt modules
    07 1.60 volt modules
    19 1.50 volt modules
    01 1.25 volt modules
  • 1 Hide
    jee_are , May 13, 2013 6:26 AM
    Maybe I'm being anal but, Westmere (Nehalem) was the die shrink to 32 nm (tick). Sandy Bridge was the following change in microarchitecture (tock).
  • -1 Hide
    DjEaZy , May 13, 2013 9:41 AM
    ... i got me the crucial balistix 3~4 months ago... a 16Gb of them... and they OC good too... i have them running @ 1926Mhz 8-8-8-26
  • 0 Hide
    Evan Richardson , May 13, 2013 9:47 AM
    HaserathNo power consumption numbers?


    Perhaps because memory doesn't use that much power to begin with? Be a cold day in hell when you have to buy a 1kW PSU just because you add another stick of ram.
  • 0 Hide
    happyballz , May 13, 2013 10:40 AM
    Where are the cost for each kit? Did I miss it? Flipped through pages and could not find anything on the cost.
  • -1 Hide
    gondor , May 13, 2013 2:34 PM
    JackNaylorPEAnybody read Intel's web pages in this regard ?1.5 volts is for the JDEC profiles ...


    It's "JEDEC", the first 'e' is not silent/missing.

    http://www.jedec.org
  • 2 Hide
    m32 , May 13, 2013 3:16 PM
    HaserathNo power consumption numbers?



    3-6 watts isn't going to kill anyone.
  • 0 Hide
    pazygozo , May 13, 2013 6:05 PM
    Exactly the article i wanted to read, i was asking myself what clocks could the low voltage modules achieve at high voltage.

    God, i wanted to buy the ballistix tactical in february, i bought the ballistix sport instead because i found 32GB for 158$ but they are taller and 1.5v rated, glad to know it doesn't make much of a difference in games past 1600Mhz.

    Great work!
  • 0 Hide
    Crashman , May 13, 2013 10:32 PM
    happyballzWhere are the cost for each kit? Did I miss it? Flipped through pages and could not find anything on the cost.

    On the day they were tested, Adata was $72, Crucial $70, Geil $75, G.Skill $68, Kingston $70. That changes pretty quickly though.
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