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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  • Khenglish - Tuesday, December 17, 2013 - link

    Your tRFC and tRRD rows are flipped in the table on the first page.

    That tRFC is ridiculously high. Cut it by 150-200 in XTU (yes, by up to 200. It's that ridiculously high) and you'll see around a 500MB/s bandwidth improvement. For reference I've run 2133 CAS9 stable at tFRC 128 in a laptop.

    Also it would be nice to see results on an IVB system as well as Haswell. IVB is just as good at the top end, but I've seen signs that haswell has a better IMC, so while this memory is stable on haswell, it might not be on IVB. Also most people still have an IVB or SB anyway.
  • Gen-An - Wednesday, December 18, 2013 - link

    You can't cut the tRFC by much on these, they use 4Gbit Hynix H5TQ4G83MFR ICs, and especially not at the high clocks they're running. It's going to be over 200 at about any speed, and you pretty much have to run it at 396 or so for 2933.
  • Hairs_ - Tuesday, December 17, 2013 - link

    Can we please stop this series of articles now? please?
  • jasonelmore - Tuesday, December 17, 2013 - link

    yeah enough with the RAM reviews. we've been on DDR3 for almost 10 years,
  • Jeffrey Bosboom - Tuesday, December 17, 2013 - link

    The only explanation I can think of for all these RAM reviews is that in exchange for samples, Anandtech is obligated to provide brand exposure. Otherwise there'd just be one roundup saying "yeah, they're all about the same". If that's the case, I feel sorry for Ian, who surely has better things to do with his time.
  • Navvie - Wednesday, December 18, 2013 - link

    This is what I figured, the original article was quite interesting. But this is really scraping the bottom of the barrel for article ideas.
  • DanNeely - Wednesday, December 18, 2013 - link

    Gotta agree. At most this should be a twice a year round up; maybe only once yearly depending on how frequently binning changes switch out which clock/cl combinations offer the best bang for the buck.
  • Gen-An - Wednesday, December 18, 2013 - link

    Ian, you state these sticks are using Hynix CFR, but CFR is a 2Gbit IC, it'd be impossible to make an 8GB DIMM with them. This has to be Hynix 4Gbit MFR.
  • ceomrman - Tuesday, December 31, 2013 - link

    Hmmm... couldn't this article just say "premium RAM is a hoax. Just buy some decent sticks from a known brand with plenty of 4 or 5 Egg reviews, and go with 1866 MHz if your motherboard will support it. Go ahead and buy faster RAM, but don't spend much since the performance impact is not noticeable in the real world."
    There are zero users who would not benefit more from some other use of the money, either in their savings account or in the form of a bigger SSD, nicer motherboard, more efficient PSU, faster CPU, etc.
    Dog + pony show = Blech.

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