RAM Overclocking Guide: How (and Why) to Tweak Your Memory

Warranty, RAM Cooling And Final Note

Vendors, Damage And Warranty

We’ve discussed damage to ICs and electromigration in the context of overclocking before, and we’ve mentioned vendor-advertised default values for RAM performance.

There are many RAM vendors, but not all manufacture the ICs they use to build modules, and there are only a handful of memory manufacturers, including Samsung and SK hynix. The kit vendors purchase memory ICs and solder them onto PCBs. Different vendors may list different values for voltages and timing latencies using the same chips.

Vendors test each chip in order to program the EEPROM on-board the module with voltage and timing latencies; it is the integrated memory controller and parameters set via the motherboard firmware that control the memory’s final voltage and timing in the system, so once power has been turned off, there is no way to check what parameters or voltage were applied to the memory, short of actual physical damage.

Often, the pre-programmed memory frequency and latency values on the DRAM’s EEPROM are lower than the actual advertised value; the memory will boot with conservative settings for compatibility with a wide variety of systems. From there, voltages, latencies and clock rates must be set via the motherboard firmware. This is by design from the vendor’s point of view, and will not violate the warranty.

Straying above the datasheet voltage value (1.5 or 1.65 or even 1.8 volts) or loosening the RAM timings leaves no trace on the chips themselves. In fact, the bottleneck for memory voltage is the IMC (e.g. 1.55 volts for Intel’s Sandy Bridge CPUs).

Keeping the above factors in mind, there are two major sets of values you should check before overclocking the memory chip:

  • The maximum memory speed, clock rate, and voltage allowed by the CPU and/or the IMC. These values can be exceeded, but that really depends upon the silicon lottery, and there is a higher chance of causing physical damage.
  • The maximum voltage and speed for the specific memory module (not the vendor’s advertised values). This requires a glance at the original memory module manufacturer’s datasheet.

RAM Cooling

There is some disagreement in the overclocking community about how much RAM benefits from active cooling. RAM doesn’t really perform too much better at cooler temperatures, but serious overclocking still heats up the memory chips. On the whole, unless a system is intended for extreme benchmarking or testing, passively cooling the memory chips is sufficient, though having an additional fan blowing air over the area certainly won’t hurt.

If you are already using a CPU liquid-cooled loop, putting in a water block for the RAM is relatively easy if that's the route you want to go. Alternatively, vendors have water cooling-ready memory packages, like the Kingston HyperX H2O series.

This brings us to heat spreaders and vendor-supplied heat sinks. It used to be that spreaders were almost purely aesthetic. There are also reports that certain vendors have, in the past, glued heat spreaders on to disguise the quality of the memory modules or ICs. But current-generation heat spreaders from reputable vendors do make a difference in operating temperatures, and when the same kit is provided in two different packages—one with a heat spreader and one without—going for the heat spreader makes technical sense.

A Final Note: “Overclocking” Memory vs. Regular Memory

Apart from the aesthetics and marketing, there is no specification difference between “overclocking” or “pro” or “gaming” memory and regular memory if the same IC is used. However, given the chip-to-chip variability of memory modules, vendors will often test and pre-select higher-performing modules/chips, label them as “overclocking” memory, perhaps add a heat spreader and, most important, set the pre-configured timings in the EEPROM to values optimal for overclocking, given a certain training regimen. This only applies to reputable vendors, though—any memory can be overclocked, and marketed as such.

MORE: Best Memory

MORE: DDR3 DRAM FAQs And Troubleshooting Guide

MORE: The Most Common DDR DRAM Myths Debunked

MORE: Navigating the Memory Upgrade Jungle

MORE: All Memory Content

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  • Sakkura
    Perfect timing, I was just about to get to work on my DDR3-1600 kit. Gotta squeeze out all the performance possible from my aging Ivy Bridge build. Especially now that I'm running VR.
  • Amdlova
    No i don't want oc the memory if i can't oc the ssd :)
  • BobsKnob
    You know why there's no benchmarks? Because overclocking memory offers such small 'real world' gains that it's not even worth it. You might as well try to overclock your usb ports. This is just a lame attempt to advertise products, in this case Kingston and Arctic heat spreaders and try to pass it off as reporting.
  • derekullo
    They also mentioned Mushkin, Crucial and G.Skill.

    Heaven forbid they mention the manufacturer of the ram in an article about overclocking ram.

    Now if this would have been an article about Farcry 5 or Elder Scrolls 6 and they had a picture of an Arctic Heat Spreader then you would have been on to something.
  • BobsKnob
    Thank you for proving my point. It's just advertising masquerading as reporting.

    You know, there used to be a time when Tom's did real, unbiased reviews and reporting. When something sucked...it sucked and the review wasn't candy coated.
  • damric
    Well done. Will there be a Part 2 that dares to tweak secondary timings and beyond?
  • dish_moose
    I'm with Bob on this one - until you show real wold benchmarks showing real improvement from OC RAM, I won't waste my time.
  • Maxxtraxx
    Check out the youtube channel Digital Foundry, this video specifically: https://www.youtube.com/watch?v=Er_Fuz54U0Y
  • Maxxtraxx
    Proof of increased performance from Ram Overclocking from real world benchmarks can be found here:

    Am I not allowed to edit my own posts? or am i really missing something here? I wanted to say more after I posted but could not find any way to edit my own post.
  • BobsKnob
    What GPU is being used for that test?
  • BobsKnob
    Also, when I skip through that video, I see a lot of the FPS's are similar regardless of ram speed.
  • Maxxtraxx
    Watch the whole GTA5 section of the video, also here is a second video from DF on the same subject:


    You'll see the same FPS results there the gains are anywhere from a few FPS more under light CPU loads to 20FPS more with heavier loads.

    The amount of FPS gained by RAM overclocking is much less consistent when compared to GPU overclocking due to it being bound to the CPU job of keeping the GPU fully fed without bottle-necking.

    The CPU can go from doing very little to supply the GPU to doing a great deal at different times during the game. The GPU, unless it hits a frame limiter like v-sync will be running at 100% all the time unless it is bottle-necked by the CPU.
  • blackmagnum
    Did you know that overclocking the memory might corrupt the data? That's why you should only overclock ECC memory.
  • inmyrav
    How about some measurements to show the alleged benefits of overclocking memory? I have never seen a significant impact on gaming performance even from significant overclocks / reduced timings in memory. I'd be interested to see how much the benefits are and where exactly they exist, if they do?
  • Sabishii Hito
    Memory OC is mainly for fun and competitions, and I thoroughly enjoy it.
  • daglesj
    Buy the ram that looks the coolest in your motherboard. That's the only valid advice you need these days.
  • g-unit1111
    That's very interesting. I had no idea you could identify that much from a RAM module. Kind of like how you can identify everything about a car from the VIN number.
  • JackNaylorPE
    But current-generation heat spreaders from reputable vendors do make a difference in operating temperatures, and when the same kit is provided in two different packages—one with a heat spreader and one without—going for the heat spreader makes technical sense.

    What is the difference ? Why is it significant ? Here I see the aesthetics as the primary driver here. Yes, of course, two sets of modules, one with and one w/o the HS, take the one with ... but what is the thermal issue here ?. I have not heard of an issue with RAM temps since DDR2. As an analogy, while I saw the reasoning behind putting a hybrid cooler on a FuryX, what is the point on a AIB GTX 1070 ? The card operates well below (10C) it's throttling point on air so, exactly, what is the hybrid doing for me ? What do I get out of the extra $100 ?

    The only cooling effect of these big tall toothy coolers is that they "look cool". While they served a purpose (when they were effective) w/ DDR2, they were absolutely useless on DDR3. And DDR4 runs even cooler.

    At more than 2" tall in certain areas the Corsair Vengeance could pose a problem for users like me who use large coolers such as the Scythe Mugen 2. I was able to use the Corsair Vengeance only after I mounted the fan on my cooler on the backside. Size is definitely a concern with heat spreaders of this size and therefore I encourage users to check that they will have enough space under their heatsinks before purchasing the Corsair Vengeance kit.

    The problem I have with the Corsair Vengeance is the same I have with many kits of RAM on the market. Companies insist on putting large coolers on their RAM and it limits the choice in CPU heatsinks that can be used within users system. DDR3 does not require these elaborate coolers with its lower voltages which translate to lower temperatures then RAM saw during the DDR, and DDR2 era. Corsair is correcting this with low profile versions of its Vengeance line but ultimately I would like to see the average size of coolers drop instead of having to look for specific low profile versions of a memory line.

    When such a "makes a difference" statement is made, as a reader, I want to see the data behind the conclusion.. 1) what are the differences in temps ? 2) how is this significant ? and 3) what are the performance impacts in something we actually do (besides benchmarks).

    With regard to the "glued on" comment, this is an issue that we never see mentioned in reviews / comparisons. Some RAM HSs can be removed with a screw ... some are glued on, why not mention this in a comparison review ? GFX card reviews typically include, RAM manufacturer, specs, how it is being cooled and yet this is rarely done for system RAM.

    Would love to see time and effort put in to showing more than "same ole same ole".

    For example, gaming average fps is limited primarily by the GFX card performance... tho there is some general acceptance that CPU can be limiting in certain games, especially when in multi-player mode. What is less accepted is that memory speed can affect performance... and when this subject is argued, we oft see links to tests that "prove" the hypothesis via "google something that shows this". Sometimes that results in a link that can prove both opposing arguments


    Metro 2033 shows no performance gain going from 1600 to 2400 DDR speed, and yet F1 shows an 11% increase in average fps. Like anything else, system performance is impacted by the weakest link in the chain. If RAM is not the weakest link, then the impact is zero. So a "test" that "proves this" is misleading. To make testing useful, the script should involve determining under what circumstances RAM becomes the bottleneck and then seeing if faster RAM or overclocking can have in impact.

    Among the areas of relevance therefore, based upon past articles on the topic.

    -what games / programs can be impacted ? (CAD, video editing ...)
    -what actions within those games / programs can be impacted ?
    -what parameters need to be analyzed ... for example min fps vs avg fps ?
    -Is the test bed adequate to perform the evaluation ... for example, what happens to previous tests when 2nd GFX card is added ? ... 3rd and 4th

    Was never a popular undertaking, my guess cause of the amount of effort involved, but here's some old links which did look into some of these aspects


    22.3 % (SLI) increase in minimum frame rates w/ C6 instead of C8 in Far Cry 2
    18% (single card) / 5% (SLI) increase in minimum frame rates w/ C6 instead of C8 in Dawn of War
    15% (single card) / 5% (SLI) increase in minimum frame rates w/ C6 instead of C8 in World in Conflict

    Also see http://www.bit-tech.net/hardware/memory/2011/01/11/the-best-memory-for-sandy-bridge/1

  • gamebrigada
    You should mention that some games do not like memory overclocks. Ubisoft is pretty famous in this regard some of their games will run very low frame rates with any overclock no matter how stable. FarCry 4 is a good example.
  • RedJaron
    Everyone asking for benchmarks showing the benefits of OC'd RAM, look back at any number of SBMs, particularly any Codemasters racing games. You will see big fps gains when RAM bandwidth is increased. Other games, hardly anything. This is nothing new. Most games don't care about CPU OCing either.

    However, games aren't the only thing computers are used for. Many professional apps, particularly Adobe products like Premiere and After Effects, are very RAM sensitive.

    330381 said:
    You should mention that some games do not like memory overclocks. Ubisoft is pretty famous in this regard some of their games will run very low frame rates with any overclock no matter how stable. FarCry 4 is a good example.
    I'd love to see the proof of this. It's not difficult to OC your RAM poorly, resulting in lower performance all around, not just in one game. My suspicion if that is the case you saw here, if indeed you did see it and aren't simply repeating something told you.
  • anbello262
    Everyone who is asking for benchmarks, and saying that it makes no sense for gaming:
    Go and read the articles referenced on the first page. There are 4 articles that explain everything you're complaining about.
    It would make no sense to write everything again, that's exactly the point of referencing previous articles.

    It is even explicitly said that OCing ram makes little sense for gaming (except for a very small number of games), but that it can have quite a big impact on other applications, like WinRAR, CAD, Media editing or MATLAB, even more if heavily multitasking. Benchmarks included.

    By the way, right now I'm celebrating my mix&match 24GB of DDR3 (Sniper 2x4 2400@11 + RipjawsX 2x8 2133@9) running at 2200@9 with little effort. I was worried I would have to losen the timings, but it has worked better than expected, with even a mild OC.
  • damric
    Experts know that memory latency has always been bottleneck for gaming. Overclocking timings/frequency/memory controller adds significantly to minimum FPS, which can mean the difference between a stutterfest or smooth rendering. The uninformed user only looks at maximum FPS, which is the GPU bound portion.
  • dish_moose
    looking at these benches : http://techbuyersguru.com/gaming-ddr4-memory-2133-vs-26663200mhz-8gb-vs-16gb?page=4 You don't get a lot of bang for the buck by using the fastest RAM - When buying RAM, I generally go for the fastest RAM(speed & Timing) that has the best price/performance ratio. I rarely OC memory unless my CPU OC also speeds up my memory clock.
  • anbello262
    Why would you not OC memory, when you don't actually pay any extra for it?
    It's completely free, and it comes with a small performance upgrade (depending on the application).
    More performance, same price = very good deal, unless your time is too valuable and you dislike overclocking, in which case probably this article isn't for you.