DDR4 3000 RAM with an i7-5930k CPU question

[AnaB29]

Hello,

I've just ordered some parts for a new build, here is a partial list:

CPU: i7-5930k
COOLER: CM Hyper 212 EVO
MOBO: ASUS Rampage V Extreme/U3.1
RAM: G.Skill Ripjaws 4 DDR4 3000mhz 4x8gb
PSU: SeaSonic Platinum-1000W

I intentionally ordered the RAM in the 3000 speed because I was considering learning how to overclock. I understand that the CPU supports DDR4-2133 RAM, but can be tweaked to support faster frequencies.

I'm not gaming at all, this system will be used for programming scripts to back test large-ish files of market data.

I've built 4 systems and the idea of overclocking has held my curiosity for years, though I've never really considered doing it until now.

Questions:
1. Is my cooler choice sufficient for overclocking? I've noticed in a lot of tutorials that water coolers are used.

2. If I change my mind and do not overclock, should I return the 3000 RAM and order 2133?

3. If I install the 3000 RAM but do not overclock, are there any potential concerns for the CPU that I should be aware of.

4. Is it true that if use the 3000 RAM and 'underclock' it to 2133, that the RAM will be more stable than installing 2133 RAM to begin with?

5. In terms of percentage of gain in performance/speed, what is a reasonable amount to expect?

There is a $70.00 difference in the prices of the two RAM choices, not a huge consideration, but if the cons of overclocking outweigh the pros of gain, then I'd rather go with the 2133.

Thanks,
Ana

 

[rhysiam]

A few general answers:

Once upon a time (LGA 1155 era) overclocking the CPU meant that you needed to OC your RAM too, but things have changed and the two can be clocked independently now. You don't need fancy RAM to OC your CPU.

That kit is a 1.35V kit if run as rated, which is more voltage than stock (1.2V for DDR4), so will push things a little harder. But you've got high end components there so shouldn't be an issue at all.

In terms of achieving the rated speed of the RAM, all you *should* have to do is enable the XMP profile in the BIOS.

Now the questions:
1) No, not really. A light OC would be fine on that cooler, but those Intel extreme platforms get very hot when OC'd, and need serious cooling. A 240-280mm water cooler or high end air cooler (like the Noctua NH-D15) is recommended if you want a substantial overclock. The 212 would handle a light OC, but you'd run into heat issues before you got too much extra voltage into the chip.

2) The fast RAM is honestly of limited value anyway. OCing or not. I'd be running 2400Mhz RAM or thereabouts and spending the saving on a better cooler if I was in your shoes. But it's not bad or a problem, just not the best place to spend money on a limited budget.

3) No - higher voltage on the RAM does work things a little harder - but not really an issue

4) "more stable"... hmmm... I think something's either stable or it's not. I suppose you'd be running it well under spec, so perhaps "more stable", but I think stock RAM at stock clocks is 100% stable... which you can't really improve on.

5) With proper cooling on a 6 core processor you can get to around 4.5Ghz on all cores. That's not a big gain for single-threaded workloads (10% or so), but is more like 20-25% gain in workloads that use all cores. You need proper cooling for that though.

 

[AnaB29]

A few general answers:

Once upon a time (LGA 1155 era) overclocking the CPU meant that you needed to OC your RAM too, but things have changed and the two can be clocked independently now. You don't need fancy RAM to OC your CPU.......

Thanks Rhysiam for your speedy and informative response.

So if I enable just the RAM clock speed in XMP, would that increase the 135V of the RAM potentially increasing stress on CPU? Sorry for any newbiness here, but this is all so...new...to me

 

[wyliec2]

You've got a nice selection of hardware but went cheap on the cooler.

I have used a couple of Noctua with excellent results. Most recently a NH-D15 on a 5960x with 4.4ghz OC. I'm using 2666 RAM without issue just applying the XMP profile - 1.2v. On a different build (4770k @ 4.3ghz) I used 2400 DDR3 RAM and was able to use the XMP profile and then lower the voltage (I think it was 1.65v RAM) to 1.57v.

If it was me I'd get the Noctua (presuming it will fit your case) and see what CPU OC I could get and then try the RAM XMP profile - once everything is stable try reducing CPU and/or RAM voltage...

 

[AnaB29]

Thanks again for your help, I'll get the better cooler.

Have a Wonderful Holiday!

 

[rhysiam]

Thanks Rhysiam for your speedy and informative response.

So if I enable just the RAM clock speed in XMP, would that increase the 135V of the RAM potentially increasing stress on CPU? Sorry for any newbiness here, but this is all so...new...to me

Most welcome.

Yes - that's right with the RAM. Basically there are loads of different, complex settings with RAM which can affect stability. Manually setting them all can be complicated and tedious. So we have "XMP Profiles" (stand for extreme memory profiles) which are stored on the RAM itself, and basically tell the system the exact settings to use. That allows the RAM manufacturers (who know their hardware and understand all the settings) to do all the stability testing for you, identify an ideal balance between performance and stability, and then store those settings on the RAM itself so your system can apply the exact settings. Saving everyone a load of hassle.

+1 for a better cooler! 🙂

Good luck.