2400 MHz Memory running on 1600 MHz?

[SirFiddlesticks]

Hello,

I've recently bought new 16Gb (2x8 Gb) memory sticks. Their model is "Hyper-X 16GB DDR3 2400 MHz CL11" - HX324C11T3L2/16.

I've found that they're running at 1600 MHz instead of their 2400 MHz... I've searched around a bit, specifically a bit on these forums but all I've come up with that people tell to change it in the bios... Which I did, but after changing the memory frequency multiplier from 16x to 24x (to get the 2400 MHz), the entire computer wouldn't boot. When I tried to boot it again, it ended up booting for 3 seconds, the fans turning on and then it closes immediately, and going into a loop of turn on for 3 seconds then shutting off again.

I have no clue what to do at this point and any help would be greatly appreciated! I'm very new to this so I am not very experienced on this whole ordeal, so please bear with me.

These are my system specs, since I'm sure they'll come in handy.

Operating System: Windows 7 Ultimate 64-bit SP
CPU: Intel Core i7 3820 @ 3.60GHz
RAM: 16.0GB Hyper-X DDR3
Motherboard: Gigabyte Technology Co. Ltd. X79-UD3
GPU: Nvidia GTX 690

Thanks in advance!

 

[Tradesman1]

Make sure you have the latest BIOS - then enter the BIOS and enable XMP - select profile 1. If any problems may need a slight OC of the CPU to carry 2400 at 2400

 

[kraelic]

Spec is 1600 for boot compatibility. Do enable the XMP profile, it will set the timings. Though I think I read that the x79 had issues with high speed ram.

 

[SirFiddlesticks]

So what I managed to pull off is to make the memory at 2133 MHz on the motherboard without the XMP.
Turning on the XMP on any frequency causes the system to fail to boot... Mind that I had previous RAM that was G.Skill Sniper 2133 MHz and it could run perfectly with XMP on.
I have no clue what to do next... I've tried different frequencies with the XMP on with my existing Hyper-X ram, and it always fails to boot, and yes I did have "Profile 1" as the selected option.
I'm not really experienced at this so I'm not sure about the OC'ing of the CPU for the RAM to work and all.

Help is greatly appreciated! Thanks in advance.

 

[Tradesman1]

The CPU is capable and rated to 1600, so when going higher it often requires a CPU OC to help the CPUs internal memory controller. Very common problem and depends on the individual CPU, another 3820 might easily run 2400 at stock while yet another one might have trouble even running 1866 😉

 

[iamacow]

Just enable XMP memory profile in the Bios. It will bring it up to 2400. If you just change it to 2400 in the bios, you have to change the voltage along with everything else and timings. the XMP method is very easy and idiot proof.

 

[SirFiddlesticks]

The CPU is capable and rated to 1600, so when going higher it often requires a CPU OC to help the CPUs internal memory controller. Very common problem and depends on the individual CPU, another 3820 might easily run 2400 at stock while yet another one might have trouble even running 1866 😉

So am I basically getting (edited, profanity not allowed) over by the silicon lottery? Or can I do something about it? Do I have to necessarily OC my CPU -which is currently defaulted at 3.6 GHz- so that I can go from the 2133 mark to 2400 without failing to boot?

Also, can you please tell me whats the difference between XMP and default? Like if I am running at XMP 2133 and default 2133, is there a difference? Because my system sure does think so, since it fails to boot at 2133 XMP but it happily boots at 2133 default.

Thanks a lot man!

 

[Tradesman1]

Another option will be to try raising the VCCSA voltage to give the sticks a boost - try it at 1.25....and yes in part on the silicon lottery, - each CPU is individual - Asus did some interesting testing with 4770Ks awhile back.

http://www.hardocp.com/article/2013/06/01/intel_haswell_i74770k_ipc_overclocking_review/6#.V75Juk0rJD_

 

[SirFiddlesticks]

So to recap what I need to do...
I need to OC my CPU (currently at 3.6) in order for it to be able to run XMP profile for the new RAM? And if I need to OC it, what values should it go to? Since it's at 3.6 normal and 3.7 turbo.

What I don't understand though is that XMP DID run for the sticks before it on 2133, but its not running now for the 16 GB ones even at the same frequencies, and I had 8, 2x4 previously.

And what voltage do I increase? I already see the voltage at 1.65V last time I opened the BIOS.

 

[Tradesman1]

2133 isn't 2400, as far as default the mobo defaults to 1600. 2400 is faster and needs more from the MC (memory controller) at stock speed and with stock voltages, your individual CPU doesn't appear up to it (and most other 3820s are the same. Your in the same boat as many, as mentioned above by Iamacow, many believe that XMP just works regardless of CPU which just isn't so, I did a FAQs and Fiction article for Toms and addressed this exact issue in the Fiction part, page 4:

http://www.tomshardware.com/answers/id-2741495/ddr3-faqs-fiction.html

 

[iamacow]

X.M.P settings work regardless, doesn't mean the CPU can handle it is what I meant I guess. You could enable the X.M.P profile and than set it to 2133 or 1866.

 

[SirFiddlesticks]

2133 isn't 2400, as far as default the mobo defaults to 1600. 2400 is faster and needs more from the MC (memory controller) at stock speed and with stock voltages, your individual CPU doesn't appear up to it (and most other 3820s are the same. Your in the same boat as many, as mentioned above by Iamacow, many believe that XMP just works regardless of CPU which just isn't so, I did a FAQs and Fiction article for Toms and addressed this exact issue in the Fiction part, page 4:

http://www.tomshardware.com/answers/id-2741495/ddr3-faqs-fiction.html

No, what I meant is that it ran 2133 on XMP for the previous sticks, but it's not running 2133 XMP on the current one, but only as a default profile.

And didn't you say I can increase the voltages up slightly by the value you gave in order to try to boost it up to 2400? Or am I getting this wrong?

If I am to run it on 2133 on default profile, what else do I need to alter other than the memory multiplier? What voltages and to what specified numbers, for example...

Lastly, is the failure to boot just the processor just telling the system that it cant run this because the RAM clock is too high? Or can it be avoided if certain overclocks happen or certain voltage increases happen?

 

[Tradesman1]

Your current 2400 probably doesn't have a profile for 2133 (DDR3 generally has 2 XMP profiles both for the advertised data rate, here 2400), the spec profile and an enthusiast profile (which normally is not much more than the CR at 1T)

You can try enabling XMP, Profile 1 and then make the suggested voltage changes - once all done, save, exit and try booting