Sign in with
Sign up | Sign in
Your question
Solved

Haswell Memory Voltage Question

Last response: in Memory
Share
June 30, 2013 7:53:31 PM

I'm building a gaming computer and I'm noticing that some RAM is 1.65v and when I add it to my build on pcpartpicker it says that Haswell may make the RAM run slower or it will run over what Intel says is ok. Will I run into any problems if I get ram over 1.5v? (4770K with MSI Z87 MPower)

Thanks in advance

Best solution

a c 554 4 Gaming
a c 1942 } Memory
June 30, 2013 7:58:43 PM

What DRAM, if voltage is 1.65, it should be at least 2133 sticks...1866 and below 1.5 is preferred....the 2133 and up will require an OC of the CPU which balances out the DRAM voltage as MC (memory controller voltage is higher)
Share
a b 4 Gaming
a b } Memory
June 30, 2013 7:59:53 PM

Don't run RAM over 1.5V with Intel chipsets - it voids warranty and shortens life.

Haswell automatically clocks RAM over DDR3-1600 down, but you can OC it back to original settings.
m
0
l
Related resources
Can't find your answer ? Ask !
a c 554 4 Gaming
a c 1942 } Memory
June 30, 2013 8:03:53 PM

Only shortens life if out of balance with the MC, that's why you don't want sticks 1866 and below over 1.5... Ocing the CPU also 'VOIDs' the warranty...sort of makes you wonder why Intel even sells unlocked CPUs ;) 
m
0
l
a b 4 Gaming
a b } Memory
June 30, 2013 8:15:05 PM

Not sure how "out of balance" can affect it - it's simply that a higher voltage puts more force on the electrons, forcing them through the insulator faster, reducing it's effectiveness.
m
0
l
a c 554 4 Gaming
a c 1942 } Memory
June 30, 2013 8:38:31 PM

Really, Intel is very spec oriented, JEDEC originally called for 1.5 on DDR3 (and also took DDR3 ONLY to 1600), Intel calls for DRAM voltage and MC (memory controller) voltage to remain within 0.6 of one another...At stock 1333/1600, the CPU generally run a MC voltage of slightly under 0.10 depending on the mobo...when OCing the the CPU the MC voltage rises allowing also for higher voltage DRAM... I myself won't touch sticks 1866 or lower that run 1.65, or 1600 running 1.6....2133 is about the sweet spot for DRAM at 1.6 to 1.65, though lower is still better, and it has no ill effect on effectiveness if the sticks are slected and set up correctly
m
0
l
a b 4 Gaming
a b } Memory
June 30, 2013 8:57:06 PM

The only reason voltage goes up as frequency goes up is that higher-clocked chips need more voltage to reach those clocked. Consider chips above 1.5V to be "factory overclocked".
m
0
l
a c 554 4 Gaming
a c 1942 } Memory
June 30, 2013 9:16:30 PM

Bet you also believe that CPU-Z also displays the actual chip in the max bandwidth pane of the SPD tab

When a manufacturer gets a production lot of ICs (memory chips), they are tested to meet specs at a given freq, if they pass they go to the next freq, pass they move along fail at a given spec, they get binned at the previous freq, and so on.

Many times, specific different IC models are used for a particular model line of DRAM and they go through the binning process also....

You as the user, can OC your sticks, but they are manufactured to certain specifications in order to meet the specified frequency. Then they go through the process of being tested to work together with other sticks to put out different size sets, which then have their SPDs flashed to the specific set timings, XMP and specs....If it was as simple as you say they would only sell single stick packages at a higher price and make even more money.....there's alot more to DRAM than what you are aware of
m
0
l
a b 4 Gaming
a b } Memory
June 30, 2013 9:22:18 PM

Yes, I know they bin the chips, you raise the frequency (or drop the voltage) until they fail. Then similarly binned chips get stuck on a stick with an appropriately programmed SPD. My point was that a 1.65V DDR3-1866 could be from the same bin as a 1.5V DDR3-1600 (at a guess, I'm not sure of the exact derating curves), because the higher voltage allows a chip to operate faster, though different bins would have a different derating constant.
m
0
l
a c 554 4 Gaming
a c 1942 } Memory
June 30, 2013 9:39:45 PM

1.5 to 1.65 in a single step, don't think so, and you'll seldom see a production lot used in more than a couple of steps....say 1600 and 1866, then further binned by CL....generally different voltage sticks will come from different production lots or models of ICs
m
0
l
a b 4 Gaming
a b } Memory
June 30, 2013 10:16:18 PM

My point is that you would use nearby bins for those (at a guess, as I said I don't know the derating curves). This can be seen in the SPD tables, where you can see the voltage, latency, and frequency dropping together.
m
0
l
a c 554 4 Gaming
a c 1942 } Memory
June 30, 2013 10:41:34 PM

You HAVE to have the DIMMS able to boot at a mobos default boot freq which normally is 1333 or 1600 at 1.5, it needs to have compatible settings. Mobos don't see the DRAM and automatically boot to what the DRAM freq is...Also that have to be able to underclock for the simple reason that many don't have a clue about DRAM and look at their mobo specs, there's questions all the time like hey my mobo can run 2400 sticks, why won't mine work and they are running an I3 or locked i5/i7 which CAN'T run 2400 (which is why most all DRAM speeds on mobo list show an '(OC)' beside the DRAM freq for 1866 - Most think that means they have to OC the DRAM....wrong....it means an OC of the CPU may/is required. And just for info the Max bandwidth pane in the SPD page of CPU-Z is the default boot spec for the sticks, see my info thread here:

http://www.gskill.us/forum/showthread.php?t=10565

and a QVL info thread here:

http://www.gskill.us/forum/showthread.php?t=10566

Also there's a new version of CPU-Z available 1.65

http://download.cnet.com/CPU-Z/3000-2086_4-10050423.htm...

m
0
l
a b 4 Gaming
a b } Memory
June 30, 2013 10:47:02 PM

You can run a DRAM OC without OCing the CPU - though the CPU may need to be unlocked to do so. You need to OC the IMC, even if it is within the published specs of the RAM.

I never said a single thing about CPU-Z. I've been talking about what voltage the actual chips on the RAM need to do a given frequency, and how binning is used to achieve that.
m
0
l
a c 554 4 Gaming
a c 1942 } Memory
June 30, 2013 10:58:30 PM

Which is why i said "may/is required", it won't matter if the CPU is unlocked or not, if you DON'T need an OC per you "though the CPU may need to be unlocked to do so", if you leave the CPU at stock, you can either OC the DRAM or you can't..period..obviously you know much more about all this than I or anyone else knows, and the techs, FE's, etc from the DRAM manufactures are lying to folks like me (and the builders/consultants and IT folks I network with) that deal and work with them on a rather regular basis....
m
0
l
a b 4 Gaming
a b } Memory
June 30, 2013 11:08:14 PM

I'm trying to find stuff out, and for now your knowledge is just as good as mine, except I know my reasoning/sources but not yours. I've never heard any of your stuff from anything I consider a reliable source.

Explain why I might need a CPU OC to OC the DRAM (assuming we are talking about multipliers, rather than FSB and OCing both).
m
0
l
a c 554 4 Gaming
a c 1942 } Memory
June 30, 2013 11:36:17 PM

Briefly the FSB allowed for OCing both or but one as you could drop the CPU multiplier, then came the BCLK with the P55 and X58 which linked the PEG and DMI bus into a Ring Bus, these allowed for the BCLK to OC (generally stably) from 133 to about 225), then came Sandy Bridge and the BCLK was again altered, to only support from a BCLK of the base through about 107-108.....severely limiting OCing...but...Intel Introduced the K model CPUs with an open multiplier (believe it went up to 57 on SB), so then you would multiply the CPU ratio/multiplier times the BCLK (base clock of the system), which effectively widened the paths for high freqs, with locked CPUs you have turbo-boost which often can allow folks to run say 1866 sticks and occasionally higher, though not always stably...and on the lower end i5s and i3s they may be limited to running up to 1333/1600....chipset can also play in as some of the entry level chipsets just can't support DRAM higher than 1333/1600 even with a K model CPU.....
m
0
l
a b 4 Gaming
a b } Memory
June 30, 2013 11:51:35 PM

Yes, I know what a base/reference clock is. It's often a synonym for FSB, and serves a similar purpose

Also, your walls of text are somewhat hard to read.

You do know i5s have turbo boost as well?

Yes, lower end chipsets can't OC the IMC. I know this also. You are only telling me stuff I already know. What I am interested in is:
  • Whether CPU has an impact on whether you can OC DRAM (or IMC), and if so which can.
  • Why you say that you need a 'balance' between voltage and frequency, and that lack of this cause damage, effectively meaning that higher voltages only damage your IMC if you don't turn up frequency. This sits at odd with all my semiconductor theory, and I'm confused as to why this occurs, if it does at all. Monetary impact, yes, but it doesn't hurt your IMC to reduce memory frequency.
    m
    0
    l
    a c 554 4 Gaming
    a c 1942 } Memory
    July 1, 2013 12:03:46 AM

    If I'm only telling you what you already know, then why are you asking, this is really ridiculous....tell you what how bout you explain how you are going to OC DRAM from 1866 to 2133, let's say a 18866 set at base 9-10-9-28 2T 1.5 to 2133...or even 1600 9-9-9-24 2T 1.5 to 1866 - what will be required with a 3470 locked CPU and why would an unlocked CPU make a difference (this is from your above quote) if you don't OC the CPU

    To be honest since this is the first time you bring up a semi conductor theory, which doesn't mean a whit to me, about what theories you have...show me some actual knowledge and explaing this theory
    m
    0
    l
    a b 4 Gaming
    a b } Memory
    July 1, 2013 12:28:38 AM

    Quote:
    Most think that means they have to OC the DRAM....wrong....it means an OC of the CPU may/is required.


    I'd like an explanation of that. Are we talking about an OC of the IMC on the CPU, or of the CPU itself (at which point you do need an unlocked chip)?
    m
    0
    l
    a c 554 4 Gaming
    a c 1942 } Memory
    July 1, 2013 12:31:51 AM

    I'd like an answer to my questions....You seem to know it all, you should be able to answer a basic question based upon your own quote that - you can OC DRAM with a locked CPU
    m
    0
    l
    a b 4 Gaming
    a b } Memory
    July 1, 2013 12:37:44 AM

    Quote:
    You can run a DRAM OC without OCing the CPU - though the CPU may need to be unlocked to do so. You need to OC the IMC, even if it is within the published specs of the RAM.


    In theory you can OC on any chipset/CPU, but Intel has locked down some. I'm not sure which or how far, but I know that Pentiums/Celerons are locked down to various values between 1066 and 1600. K skus are definitely unlocked up to around 2800 or 3200. i3s and locked i5s and i7s I'm not sure on, because Intel doesn't advertise DRAM specs as widely. I think, but I'm not certain, that i3s are locked, and i5s and i7s are unlocked.
    m
    0
    l
    a c 554 4 Gaming
    a c 1942 } Memory
    July 1, 2013 1:34:08 AM

    Another theory, believe you said you could, I asked how, am still waiting? In theory most anything can happen, this isn't Theory here, this is trying to help people (for me anyway), take theories to a chalkboard somewhere...With all this knowledge you claim to have, how bout jumping in and helping people set up timings and voltages on DRAM, OCing sticks, etc Should be easy for you, with what all you claim to know, how did you say it something about your reasoning and sources are better? Good, put them to use
    m
    0
    l
    a b 4 Gaming
    a b } Memory
    July 1, 2013 2:05:17 AM

    I do. I'm just arguing here because what you are saying would change my advice, essentially making low voltage RAM a bad deal instead of a good one.
    m
    0
    l
    July 1, 2013 7:38:22 AM

    :lol:  I love when people say dont run over 1.5v memory because it voids the warranty. Technically so does overclocking the cores but how is intel ever going to know?

    I've ran 1.75v for DDR3 31xx through my 4770K while benching with no real issues.
    m
    0
    l
    a c 554 4 Gaming
    a c 1942 } Memory
    July 1, 2013 8:16:14 AM

    Someone,

    Low voltage DRAM can be bad advice, many mobos aren't programmed to deal with it...so it can cause people problems and they often have to raise the voltage...Many manufacturers are releasing low voltage DRAM as a prelude to DDR4, which depending on who you talk to will spec round 1.25- 1.35...How many low voltage sets have you worked with? and on what platforms? And if this is leading to OCing DRAM (and doing so effectively) there still a lot more that palys in than simply raising the voltage (DRAM and/or MC) to get to a higher freq, both base timings and advanced timings need to be adjusted also...There's more to it than simple theory and what you may read somewhere, nothing beats hands-on experience....If you really read some of the articles and reviews out there you'll find that many 'writers' have no idea what they are talking about, dn't know how many times I see things like 'DRAM didn't boot to correct freq' (obviously it boots to the mobos default), or 'the XMP on the DRAM didn't set the correct timings" (obviously, the DRAM provides optimal settings from the SPD, it's up to the BIOS to implement the settings, which it may not be properly programmed to do), etc
    m
    0
    l
    a b 4 Gaming
    a b } Memory
    July 1, 2013 5:00:36 PM

    I've read most of the articles that come through Tom's, and some off various other sites (and yes, there are various parts that they are ignorant about). It can also be simply that the SPD is programmed incorrectly. Besides, if the low voltage RAM defaults to same speeds at 1.5V on a badly programmed MB, you use a little more power and get the same speeds as normal, but with more headroom if you choose to OC.

    Just dropping timings to get a higher frequency doesn't really count IMO. Yes, you can go to the limits without raising the voltage, but voltage also helps. LP stuff also leaves you more room for OCing without damaging your IMC.

    There's a difference between short term safe and long terms safe.

    Now, assuming that they are correctly programmed, which would you go for: 1.35V DDR3-1600 9-9-9-27 or 1.5V DDR3-1600 9-9-9-27, assuming tertiaries are similar?
    m
    0
    l
    a c 554 4 Gaming
    a c 1942 } Memory
    July 1, 2013 5:25:20 PM

    That's a good question, and don't take this wrong ;)  smile please ;)  but I'd shoot myself instead of getting 1600/9...with the humor out of the way, there's still a lot of variable if they are sticks I KNOW and LIKE, I'd maybe get the 1.35 (i.e. the GSkill 1600 4x4GB Snipers) but would prob get the 1.5 version of their sticks, the 1.35 set is $5 more and has just a bit more OC room so there it would be worth the $5 to me as I know I would OC it....that said, right now there a ton of new low voltage sticks coming out (and often being given away) that are somewhat of a merchandising tool for manufactures to play with and get feedback on in prep for DDR4...Those I will pick up here and there and experiment with on my own, for my clients I would stick with 1.5 sticks....the exceptions would prob be as stated sticks I know vs unknowns...What would also play in, is what mobo and to a degree CPU, because many mobos don't like low voltage DRAM (AMD in particular and you often have to take them to 1.4 - 1.5 to run anyway, and then you loose any anticipated headroom anyway,
    m
    0
    l
    a b 4 Gaming
    a b } Memory
    July 1, 2013 5:33:17 PM

    But the increased voltage of taking them to 1.4-1.5V doesn't take away headroom - in fact that would give you more room to OC?
    m
    0
    l
    a c 554 4 Gaming
    a c 1942 } Memory
    July 1, 2013 5:51:16 PM

    If you have 1600sticks rated for 1.35 and have to use 14. to 1.5 to run them at 1600 - how in the world can even begin to HELP? When OCing DRAM you have limited tools to assist in OCing you have the DRAM voltage, MC Voltage, Base timings, CR (Command Rate), CPU multiplier and the Advanced timings...will ignore Advanced timings as that is primarily for advanced OCers and few really know how to use them. So you have base timings (the 9-9-9-27) of which the CL is the primary tool, the CR (not really much for OCing as the norm is 2 and OCing 'generally' keeps it to 2, the CPU multiplier, and then the voltages, MC and DRAM. MC can assist in reaching a higher OC as can DRAM.....the thing with DRAM is, again 'generally', it'safe to take sticks up to about + 0.20 over spec...so with 1.5 then up to 1.7, (1.65 I try and lower that expectation to + 0.15) so 1.8, but with 1.35 the + 0.20 goes to 1.55, so if you are already haveing to run 1.4, or 1.45 then you are looking at a proposed max of 1. 6 to 1.65 vs 1.7 for standard 1.5 sticks going to 1.7....
    m
    0
    l
    November 24, 2013 11:21:39 AM

    Someone Somewhere said:
    Don't run RAM over 1.5V with Intel chipsets - it voids warranty and shortens life.

    Haswell automatically clocks RAM over DDR3-1600 down, but you can OC it back to original settings.


    So even if I find higher speed RAM like this DDR3-1866 that runs at the target 1.5V, a Haswell CPU will restrict it to 1600?
    m
    0
    l
    a c 554 4 Gaming
    a c 1942 } Memory
    November 24, 2013 3:23:43 PM

    SuperPaulio said:
    Someone Somewhere said:
    Don't run RAM over 1.5V with Intel chipsets - it voids warranty and shortens life.

    Haswell automatically clocks RAM over DDR3-1600 down, but you can OC it back to original settings.


    So even if I find higher speed RAM like this DDR3-1866 that runs at the target 1.5V, a Haswell CPU will restrict it to 1600?

    _______________________________________

    The 1866 at 1.5 is perfectly fine -
    and NO! Haswell DOES NOT automatically clock DRAM down --- would love to know where people come up with all this junk - anytime you install new DRAM or Reset the CMOS or have an OC failure, the mobo set the DRAM to the mobos default for DRAM - normally 1333 these days...It has nothing to do with the CPU - same thing happens on all Intel sockets and AMD socket mobos - with modern Intel based mobos, if DRAM is 1600 or better (faster) you go into the BIOS and enable XMP or manually set it to the spec freq.
    m
    0
    l
    !