We've abided by Intel's 1.55 V recommendation for two architectures and two die shrinks, yet most performance memory manufacturers ignore it. Recent problems with one of our builds raised the question, how far can we push RAM without killing CPUs?
Remember the Nehalem architecture? Intel’s now-historic adoption of a CPU-based DDR3 memory controller was accompanied by a warning that voltages beyond 1.65 V could fry the integrated circuitry over time, effectively killing the CPU. In those days, Intel was manufacturing its processors at 45 nm and tolerating core overclocks using 1.45 V settings. AMD was pushing far higher DDR3 voltage levels at the time, but the entire performance-oriented DRAM industry eventually adopted Intel’s 1.65 V limit.
We've since seen two die shrinks from Intel—the 32 nm Sandy Bridge and Ivy Bridge at 22 nm—with no official word from the company on what constitutes safe overclocking. Instead of commenting on the parameters you're safest sticking to, its representatives tend to quote motherboard manufacturing guidelines of 1.50 V, plus or minus 50 mV. And we thought those documents were made public expressly to help us perform pin-mods...
If Intel’s reluctance to discuss anything outside of manufacturing parameters doesn’t worry you, perhaps the covert over-voltage applied to enthusiast-class motherboards should. The industry’s dirty little secret in the days of Nehalem was a 5 to 10 mV default boost, needed to make certain poorly-programmed (Ed.: Gold-series) memory modules bootable. That extra voltage was not reported on the hardware monitoring pages of most motherboard BIOSes, and most monitoring apps failed to report it as well.
Well, if a little is good, a little more is better, right?
While Intel was busy shrinking its feature widths by roughly half, motherboard manufacturers were on a quest for overclocking records. I watched boards reach ever-higher 1.65 V memory overclocks as covert voltage tweaking climbed to 35 mV. Viewing this as a form of cheating in our motherboard comparisons, I broke out the volt meter and began reporting the setting needed to reach 1.65 actual volts in the firmware pages of our motherboard round-ups. And speaking of breaking things, a recent string of bad luck suggests that combining the accepted standard of 1.65 V and transparent over-voltage from certain motherboard vendors might not always be safe. Although that was certainly an unusual chain of events for us, it was enough for us to reconsider Intel’s 1.55 V recommendation. Can any of today’s lower-voltage RAM deliver world-class performance without breaking past that limit?

| Rated Specifications | ||||
|---|---|---|---|---|
| Data Rate | Timings | Voltage | Warranty | |
| Adata XPG DDR3L AXDU1600GC4G9-2G | DDR3-1600 (XMP) | 9-9-9-24 | 1.35 V | Lifetime |
| Crucial Ballistix Tactical BLT2K4G3D1608ET3LX0 | DDR3-1600 (XMP) | 8-8-8-24 | 1.35 V | Lifetime |
| Geil Evo Leggera GEL38GB1333C9DC | DDR3-1333 (SPD) | 9-9-9-24 | 1.50 V | Lifetime |
| G.Skill Sniper SR2 F3-12800CL9D-8GBSR2 | DDR3-1600 (XMP) | 9-9-9-24 | 1.25 V | Lifetime |
| Kingston HyperX KHX1600C9D3LK2/8GX | DDR3-1600 (XMP) | 9-9-9-27 | 1.35 V | Lifetime |
| Super Talent W160UA4GML | DDR3-1600 (SPD) | 11-11-11-28 | 1.35 V | Five Years |
We invited every major manufacturer(including a crowd-favorite ODM) to this round-up, and a few (including that ODM) chose not to participate. Of those that chose to be included, one didn’t have anything to offer with a DDR3L rating. Geil responded to our 1.35 V and 1.50 V stated test settings with a hearty "we can do that on standard RAM", and the company is now getting a chance to prove it.
- Why Bother With Low-Voltage DDR3?
- Adata XPG DDR3L-1600G
- Crucial Ballistix Tactical LP DDR3L-1600
- Geil EVO Leggera DDR3-1333
- G.Skill Sniper SR2 DDR3-1600
- Kingston HyperX Genesis DDR3L-1600
- Super Talent “Mystery” DDR3L-1600
- Test Settings
- Overclocking And Under-Latency Results
- Results: SiSoftware Sandra
- Results: Real-World Applications
- Results: 3D Games
- Which Low-Voltage Memory Kit Is Best?
This stuff was one of the 1st 30nm RAM products and came to market at Very Reasonable pricing... which lasted only until word got out about how amazing it was. Before memory prices increased this stuff about doubled in price sadly.
But that was for a reason. NewEgg last time I checked about a month back has them perm marked as discontinued (probably to convince people to buy different RAM from their desired choice, a cheap trick really), but keeps getting more in stock that only lasts days
This RAM is capable of Really Tight timings or some pretty High clocks
RAM is now officially a dull component. The only buying advice you can really give that's worthwhile is buy on size, lowest price and which looks best in your motherboard.
People are wasting too much time and effort over next to zero benefit.
In GPU benchmarks 5fps sells one card over another...
I have seen before some games like FarCry 2 will gain as much as 5 fps between brands of RAM running at same speed and same timmings @ 1920x1080. Thats worth knowing about while making a choice in my opinion
Here is these tests we saw great fps improvements than that even.
I would say too many people do not realise how Big a role RAM choice makes in todays PC builds
Sure back in the days when most games and rigs were struggling to get past the 30fps average, a couple of frames could make a slight difference but not now.
If your rig is struggling to get past 30fps then I don't think putting in 2133 DDR3 ram with ultra tight timings will help it much.
Maybe put the $70 towards a better CPU or GPU instead.
Then add another 2 fps for a good motherboard choice.
Another 2fps for a better brands design of the same GFx card model
all the little bits add up quite well.
On the whole for most gamers you are kinda right ofc, whats 5 to 15 fps when you are running 75 fps anyways... fairly meaningless in a way.
But maybe some are trying to run an ideal 120fps for 3D gaming or maybe Oculus Rift and that extra few high end of the scale fps will make the difference between a fun experience and a headache...
Its good to have reviews like this so those that Need this info can see it. Maybe the rest of us that Don't need it Now, would choose the better product so that those extra 5 - 10fps help extend the life span of our new PC ~_^