Overclocking Results

When it comes to memory overclocking, there are several ways to approach the issue.  Typically memory overclocking is rarely required - only those attempting to run benchmarks need worry about pushing the memory to its uppermost limits.  It also depends highly on the memory kits being used - memory is similar to processors in the fact that the ICs are binned to a rated speed.  The higher the bin, the better the speed - however if there is a demand for lower speed memory, then the higher bin parts may be declocked to increase supply of the lower clocked component.  Similarly, for the high end frequency kits, less than 1% of all ICs tested may actually hit the speed of the kit, hence the price for these kits increase exponentially.

With this in mind, there are several ways a user can approach overclocking memory.  The art of overclocking memory can be as complex or as simple as the user would like - typically the dark side of memory overclocking requires deep in-depth knowledge of how memory works at a fundamental level.  For the purposes of this review, we are taking overclocking in three different scenarios:

a) From XMP, adjust Command Rate from 2T to 1T
b) From XMP, increase Memory Speed strap (e.g. 1333 MHz -> 1400 -> 1600)
c) From XMP, test a range of sub-timings (e.g. 10-12-12 to 13-15-15 to 8-10-10) and find the best MHz theses are rated.

There is plenty of scope to overclock beyond this, such as adjusting voltages or the voltage of the memory controller – for the purposes of this test we raise the memory voltage to the ‘next stage’ above its rated voltage (1.35V to 1.5V, 1.5V to 1.65V, 1.65V to 1.72V).  As long as a user is confident with adjusting these settings, then there is a good chance that the results here will be surpassed.  There is also the fact that individual sticks of memory may perform better than the rest of the kit, or that one of the modules could be a complete dud and hold the rest of the kit back.  For the purpose of this review we are seeing if the memory out of the box, and the performance of the kit as a whole, will work faster at the rated voltage.

In order to ensure that the kit is stable at the new speed, we run the Linpack test within OCCT for five minutes as well as the PovRay benchmark.  This is a small but thorough test, and we understand that users may wish to stability test for longer to reassure themselves of a longer element of stability.  However for the purposes of throughput, a five minute test will catch immediate errors from the overclocking of the memory.

With this in mind, the kit performed as follows:

Test PovRay CPU OCCT
XMP 1612.21 78C
XMP, 2T to 1T No POST No POST
2933 12-14-14 1592.07 80C
3000 12-14-14 No POST No POST

Subtimings Peak MHz PovRay CPU OCCT Final PI
7-9-9 1666 1615.93 76C 238
8-10-10 1866 1610.20 77C 233
9-11-11 2200 1609.75 77C 244
10-12-12 2400 1596.13 78C 240
11-13-13 2666 1612.68 78C 242
12-14-14 2933 1612.20 78C 244
13-15-15 2933 1610.81 78C 226

With our overclocking of previous memory kits showing a rough 10% increase in PI from stock, moving from 233 to 240-245 is not that much of a jump.  When moving to higher than 2800 though, the base line PI is often fixed therein due to the high IC bin to begin with.  While we have tested kits that achieve a PI of 267, they were for a limited range (up to 2400 MHz). 

IGP Compute ADATA XPG V2: 2x8 GB at DDR3-2800 C12 1.65V Conclusions
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  • YuLeven - Tuesday, December 17, 2013 - link

    Thanks for the review.

    But with all due respect to this site that makes one of the best hardware coverage in English, I'm kind missing interesting stories lately. The late 2013 MacBook Pro, some Windows tablets, GPUs, CPUs, operate systems... anything.

    As fat as real world performance is concerned, RAM impact is so negligible for the vast majority of users that this sort of article ends kinda of... boring.

    Yet again, thank you for the article. I meant no offence in any way!
  • SeeManRun - Tuesday, December 17, 2013 - link

    Definitely agree with this one...
  • Zak - Tuesday, December 17, 2013 - link

    I have to agree that these memory articles are uninteresting and not particularly useful. As others pointed out -- and these articles confirm -- the real life difference between decent DDR1600 and super-duper ultra-high-end RAM are virtually non-existent. One article summarizing that would be more than enough.
  • jeffrey - Tuesday, December 17, 2013 - link

    Ian Cutress,
    Hello again! This is another article stating 1866/C9 being the minimum for Haswell and to avoid 1600 or less. Even going so far as to say, "Any kit 1600 MHz or less is usually bad news."

    However, this ignores 1600/C8 modules. The 1600/C8 score a 200 on your Performance Index at stock timings. This is at your recommended 200 level. There are several kits of 2x4 GB 1600/C8 on Newegg that have memory profiles of 8-8-8-24 at 1.5v. I'll repeat, these 1600 8-8-8-24 1.5v kits score 200 on the Performance Index and hit the current memory sweet spot for most people of 2x4 GB. This scores very close to the 1866/C9 kits which have a Performance Index score of 207.

    The reason I bring this up is that the 1600 8-8-8-24 kits are often less expensive than the 1866/C9 kits and offer essentially all of the performance.

    I enjoy reading your articles and appreciate how active you have been lately!
  • The_Assimilator - Tuesday, December 17, 2013 - link

    This is why I am sticking with my DDR3-1600/CL7 memory until DDR4 hits mainstream. PI = 228 which is faster than 1866/CL9.
  • jeffrey - Tuesday, December 17, 2013 - link

    Ian, any comment on 1600/C7 or 1600/C8?
  • Gigaplex - Tuesday, December 17, 2013 - link

    "In this graph the x-axis is the Performance Index of the DRAM, and thus a PI of 200 can be 1600 C8 or 2400 C12."

    This article does not ignore 1600/C8 modules.
  • Popskalius - Sunday, February 23, 2014 - link

    hi, i'm new to ddr3 lol. Re: haswell & 1600/C8, anandtech's intel gaming rig pairs an i5 with 1600/C9. Is this bc it's the cheapest build so not worth the price/performance, or is there really something bad about mixing haswell with anything slower than 1600/c8?
    thanks a bunch
  • Senti - Tuesday, December 17, 2013 - link

    And another incompetent article from Ian... Didn't even bother to read comments to the previous one to correct errors...

    Oh, and my IP (range?) is still blacklisted by stupid spam filter. Of course, I probably not love my job enough...
  • AncientWisdom - Tuesday, December 17, 2013 - link

    Lol maybe it should spam filter depending on the job happiness scale, seems legit.

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