G.Skill F4- 2666C16Q2- 64GRB DDR4-2666 Review

Remember when we used to expect per-DIMM capacity to double with every new generation of RAM? Desktop users witnessed the transition from 2GB DDR to 4GB DDR2 and 8GB DDR3. Yet, now that DDR4 is out, we’re still stuck with 8GB modules. Where are the 16GB DDR4 DIMMs?

It wasn’t so long ago that DDR3 was limited to 4GB per module. This became strikingly clear when one of my friends, a technician, was asked to upgrade a customer’s LGA 1156-based machines. Even with the latest firmware, none of those boards supported any of his 8GB DIMMs. It wasn’t until LGA 1155 that we saw a platform capable of addressing higher-density parts. And speaking of density, early DDR3 modules were limited by the capacity of available DRAM ICs to 2GB per module.

Whatever the reason for today's lack of 16GB DIMMs, the only thing a memory vendor can do for enthusiasts who want 64GB right now is to sell a set of eight modules. Some might call that an octa-channel kit, even though it's designed for quad-channel platforms. We have one such quad-channel kit in-house, which fills each of your X99-based motherboard's eight slots with an 8GB DIMM.

We’ve seen the memory development process follow a specific speed-capacity-speed path over the years, where IC manufacturers typically need several months to increase the performance of higher-density parts to the standards of lower-density predecessors. The tradeoff between density and performance explains why four-by-1GB kits persisted on the dual-channel market long after two-by-2GB kits were available.

Of course, there is a timing penalty to be paid for adding more DIMMs per channel, and we wouldn’t be surprised to hear instability stories from readers who’ve added a second set of their favorite low-latency modules. G.Skill avoids that issue by using CAS 16-16-16 timings.

A bone-stock 1.20V allows these DIMMs to remain cool while tightly packed. The same JEDEC standards don’t allow for a DDR4-2666 data rate. G.Skill programs its F4-2666C16Q2-64GRB to boot at the most compatible DDR4-2133 setting, requiring you, the enthusiast, to enable XMP mode as you chase down the kit's full performance.

Rated Specifications
Model NameData RateCapacityTimingsVoltageWarranty
G.Skill Ripjaws 4 64GB
F4-2666C16Q2-64GRB
DDR4-2666 (XMP)64GB (8x 8GB)16-16-16-36 (2T)1.20VLifetime
Adata XPG Z1 32GB
AX4U2400W8G16-QRZ
DDR4-2400 (XMP)32GB (4x 8GB)16-16-16-39 (2T)1.20VLifetime
Crucial 32GB DDR4-2133
CT4K8G4DFD8213
DDR4-2133 (SPD)32GB (4x 8GB)15-15-15-36 (2T)1.20VLifetime

Lacking another 64GB kit to compare, we pitted G.Skill’s DDR4-2666 against the easier-to-overclock configuration of 32GB four-DIMM kits, relying on Asus’ X99 Pro to optimize timings. Unfortunately, the 64GB kit didn’t reach the DDR4-3000 test point.

Best Stable Timings
Model NameDDR4-3000DDR4-2400DDR4-2133
G.Skill Ripjaws 4 64GB
F4-2666C16Q2-64GRB
N/A13-13-13-26 (2T)11-11-11-22 (2T)
Adata XPG Z1 32GB
AX4U2400W8G16-QRZ
15-15-15-30 (1T)12-12-12-24 (1T)11-11-11-22 (1T)
Crucial 32GB DDR4-2133
CT4K8G4DFD8213
N/A12-12-12-24 (1T)10-10-10-20 (1T)

The 64GB kit also required 2T timings, whereas we treated the default 2T timings of the four-DIMM sets as a mere suggestion. Next up, overclocking!

This thread is closed for comments
40 comments
    Your comment
  • SuperVeloce
    whoa, the price of those ddr4 sticks is still crazy high. For that price you can get the mighty 5960x and even if those 8 cores are "worth it" you better make a lot of money with the work you do on your computer.

    oh and your login system for forums and article comments is still pretty much broken
  • chaosmassive
    GRB = Green Red Blue ?
  • Amdlova
    for that price - i prefer stick with ddr3
  • henrik5150
    I'd stay with ddr3 cuz the price, but alas, the new haswell-e mb requires ddr4!! Darn the price of technology!!!
  • redgarl
    440$... pfff... to hell with it. You can run a computer at 4k with DDR3 easily.
  • redgarl
    Once again, no bench on games at 4k... it would tells a lot about something almost nobody know.

    We don`t really know what is the real impact of CPU and memory at UHD. Toms, just jump on the bandwaggon.
  • Agera One
    Title - G.Skill F4 64 "GRB" ??????
  • Agera One
    Quote:
    oh and your login system for forums and article comments is still pretty much broken


    This. This irritates me every time.
  • Tanquen
    I've replaced my current G.Skill 64GB DDR3 kit 4 times. They start to die about 9 months in.
  • beetlejuicegr
    Quote:
    I've replaced my current G.Skill 64GB DDR3 kit 4 times. They start to die about 9 months in.


    I also see a decline in quality of many materials in new stocks of ram and hard disk drives and graphic cards! I think this is worthy enough for a research/article from Tom's.
  • dstarr3
    Eventually, it will make perfect sense to buy DDR4 memory. Now, however, is not that time.
  • stevenrix
    Quality on hardware has been in decline for the last 5 years at least. There are 3 issues that I encounter every day at work on a global scale:
    1) Some hardware producers rush their products and they come buggy (engineering issues), then they have to re-adjust their production chains, they will change a component by a new component, .. etc this happens all the time.
    2) There are in any hardware quality issues that companies do not talk about. For memories there has been BIG BIG issues and some memories will get killed over time, it is a defective conception product, I've seen it and customers are not informed about that of course.
    3) The global commodity suppliers, they want always more for less money, so the Chinese will cut down on quality, and you get worse products.
    This shit has been going on since the recession. Everybody wants to cut down on cost, and consumers get bad products in the end.
  • firefoxx04
    Wake me up when DDR4 actually shows an improvement. I have a set of (2) 8GB ddr3 modules that run at the same speed as those sticks.. just more volts.

    I would like to see a power comparison but unfortunately it does not seem possible considering the difference between platforms.
  • Thorfkin
    I'd be interested in a comparison of DDR3 vs DDR4 performance at the same speeds where possible.
  • spectrewind
    Quote:
    Title - G.Skill F4 64 "GRB" ??????


    Those letters are in the part#.
    Purely a guess: Maybe it means G.Skill Ripjaw Blue?
  • iamacow
    funny how I bought G.Skill 64gb kit for $500 3 years ago and now 64gb kits costs $700 for DDR3 and $900+ for DDR4. What happened? I'm waiting for 128gb kits to drop below $1,000 before switching to 2011v3
  • Tanquen
    441494 said:
    Quote:
    I've replaced my current G.Skill 64GB DDR3 kit 4 times. They start to die about 9 months in.
    I also see a decline in quality of many materials in new stocks of ram and hard disk drives and graphic cards! I think this is worthy enough for a research/article from Tom's.


    Well, it has the lifetime warranty but in 30 some odd years of playing with computers I’ve never had bad RAM like this. I even got a spare 8GB stick to use when sending the 64GB kit back. The kit was like $600 when I got it and has been a totally lemon. :(
  • Amdlova
    GRB comes in Green Red and blue!
  • mapesdhs
    Tanquen writes:
    > I've replaced my current G.Skill 64GB DDR3 kit 4 times. They start to die about 9 months in.

    I've used several TridentX kits setup as 64GB total in X79 boards, with CPUs
    typically at 4.7 or 4.8, no problems at all so far after several years in some cases.
    Luck of the draw perhaps, who knows. Could be the mbd & CPU make a difference
    as to what happens to the RAM over time; someone at Intel told me this can be
    an issue with certain mbds & how the maker has chosen to implement RAM setups.

    Ian.
  • f-14
    mmm no thanks, already have DDR3 3000 at the 18-18-18-36, i don't need to drop down to 2666
  • Crashman
    361277 said:
    mmm no thanks, already have DDR3 3000 at the 18-18-18-36, i don't need to drop down to 2666
    LOL, like that's going to work in an X99 motherboard.
    Even if you're willing to settle for X79 instead of X99, I seriously doubt your DDR3-3000 kit has 64 GB. And 64 GB is the point of this kit. Once you say 64 GB, a 2666 data rate sound much better than average.
  • eklipz330
    what benefit is there of ddr4 over ddr3? it seems so minimal for personal use.
  • Crashman
    133584 said:
    what benefit is there of ddr4 over ddr3? it seems so minimal for personal use.
    The benefit of DDR4 is that you can use it on an X99 motherboard. We can all second-guess Intel for making the switch, but that doesn't get us anywhere since there are no boards that can use both.

    Intel's primary reason was apparently lower voltage. DRAM manufacturers will give you a longer list of stuff about manufacturing process and scalability, but in reality users are left with "You NEED DDR4 if you have X99".
  • gskill support
    There are specific improvements with DDR4 and the X99 platform. Those important differences and changes do not appeal directly for personal use and gaming. Make no mistake, the Z97 and DDR3 is the best gaming option on the market. X99 and DDR4 is for power users and professionals that may need maximum throughput. By using X99 and DDR4 for gaming, there will not be a significant improvement in performance, but it is not to say the two platforms are equal. Games are designed with current/previous technology. Technology moves much faster so games can not take full advantage of the latest computing power.