Why is my G.SKILL Ripjaws X 1866 RAM showing up at 1333?

DarkDubzs

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So i built my pc a few months ago and used one stick of 8gb G.SKILL Ripjaws X 1866 RAM. If i was smarter, i would have used dual channel RAM, but i can just add another stick of the same 8gb. Anyways, i was messing around and found that my computer was showing it was at 1333mhz instead of the 1866mhz the RAM said it would run at. I didnt spend my money on that type of RAM to end up getting like the slowest speed memory. How can i fix this? My full pc specs are down below in my signature.
 

legacyBIOS

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You have to go into the BIOS and manually set the speed and the XMP Profile that is on your motherboard so it will clock the RAM to 1866. Set the RAM speed to 1866 and enable the XMP Profile for that speed to get those speeds.
 
intel mb use xmp profile to set the ram speed to 1866. use cpu-z click on eprom/spd tab in the xmp profile tab write down the speed the ram set to run at. in the bios under dram speed change the ram speed there. on some of the newer amd mb they have there version of intel xmp profile.
 

DarkDubzs

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exactly what is XMP and an XMP profile? Im a stranger to all BIOS stuff.
 

legacyBIOS

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In your BIOS, you will find your RAM speed. First, you need to set it to 1866. Then there is the XMP Profile which automatically sets the voltages and clocking settings so your motherboard will run the RAM at that speed. The XMP Profile should be right next to the RAM speed setting, and it should have enable or one setting to choose from. It's pretty easy.
 
WARNING:
With a single stick you are getting HALF the performance. Since it's an 1866MHz stick you would get a maximum equivalent to a 933MHz Dual-Channel Kit so you are definitely going to have bottleneck issues.

CPU and RAM:
Most games at 1600MHz aren't bottlenecked but a few need even faster memory. Dropping below 1000MHz effective is going to throttle many games.

APU and RAM:
You actually need 2133MHz memory to maximize your APU though I would stick with your 1866MHz kit. I don't know if you could sell your single stick and buy a 2x4GB 2133MHz kit but that might be the best thing to do.

You need to do THIS:
1. Buy another stick and install it (see motherboard manual for correct slots).

2. Enter the BIOS and click "XMP" and observe that the memory frequency is correct, then SAVE.

I'm not sure why your memory is reported as "1333Mhz" but it's actual performance can not exceed HALF of what you can get with two sticks.
 

DarkDubzs

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But it said it would run at 1866mhz on the packaging of the single RAM stick. I knew dual channel was better than single, but half performance is lost?
 


Yes.
Half the performance is lost in single-channel. I was updating my post so please review my APU comment above.

Read THIS: http://www.legitreviews.com/testing-memory-speeds-on-amds-a10-5800k-trinity-apu_2106/6

Note a slow drop-off below 2133MHz down to 1333MHz. Remember your max effective with that single stick is comparable to 933MHz Dual-Channel and you can estimate how much throttling is going on.
 

DarkDubzs

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Well thats a shock. Also, i dont need better memory speeds for the apu because i am now using a dedicated gpu card. I know i need to upgrade my cpu, but when i built my pc i couldnt afford a gpu so i had to use an integrated graphics apu.
 

Tradesman1

Legenda in Aeternum
No, running in dual channel provides up to a 10-15% performance gain, it's nowhere near double....DRAM itself operates as a 64 bit device, when dual channel is enabled the DRAM is looked at as a 128 device, but the performance doesn't begin to double...With basic DRAM you'll be lucky to see the 10% gain
 


No. You're completely wrong.

Reference:
http://en.wikipedia.org/wiki/Multi-channel_memory_architecture

"The dual-channel configuration alleviates the problem by doubling the amount of available memory bandwidth. Instead of a single memory channel, a second parallel channel is added. With two channels working simultaneously, the bottleneck is reduced."
 

Tradesman1

Legenda in Aeternum
As I said it changes from being seen as a 64 bit device device to a 128 bit device - and while it improves things yes, you will not see a 100% or double performance gain, try it sometime, run your own benchmarks...what you cite at Wikopedia is theoretical, just like the designators in th PC312800 descriptions of bandwidth are theoretical, those can never be filled fully as the CPU can't feed enpugh instructions to ever fully populate the DRAM bandwidth
 


Yes, it's like saying his 4GHz CPU is throttled to 2GHz but that doesn't mean games will run at half the speed.

I probably wasn't clear enough on that. I was thinking purely bandwidth. The communication actually is at full speed during the actual data transfer process.

I initially made a big deal of it because he listed having an APU and throttling was over 60% at times.

My research shows throttling for games should vary between 0% and 30% with a decent CPU/GPU build depending on the game but if you're building a PC you don't want even 15% lower performance due to one of the cheaper elements of your system.

It would be fun to run my own tests but I don't have the time.
 
DarkDubzs,

Did you get the RAM configured properly at DDR3-1866? All DDR3 RAM defaults to standard values of DDR3-1333 or DDR3-1600, then anything higher needs to be enabled/configured by the user. Once you manually input settings, or enable the XMP/DOCP/EOCP performance profile, the motherboard will know high speed RAM is being used. The reason for all this is so the RAM can be used in any DDR3 motherboard, whether it can support the higher speed or not.

To enable dual channel, maximum performance, you will need another module. This does NOT mean the RAM will run at DDR3-933 instead of DDR3-1866. Depending on what program you use to check DRAM frequency, some will show real frequency, some will show effective frequency.

DDR3-1866 is the effective frequency, and notice not mentioned with "MHz". The real frequency of DDR3-1866 is half the number, 933MHz.

933MHz is the bus frequency of the RAM, because of DDR (double data rate) technology, this value can be doubled to have an effective transfer rate of DDR3-1866. The number value is doubled, but it is no longer "MHz", it is MT/s.

DDR3-1866 MT/s is 933MHz

This is commonly confused information, but hopefully it is more clear now.

Thank you
GSKILL SUPPORT

 

DarkDubzs

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I just went into my BIOS and looked for what you guys were telling me. I went and changed the XMP profile from i think it was set at disabled or deafult, then i changed it to Profile 2. The timings are 10-11-10-30 at 1.5V. Is that right? I didnt know which was right, 30, or 31 and i looked it up for the one stick of ram i had and it said it was 30. I found the timings from Newegg: HERE. So did i do it right? Are those timings correct for the one stick of 8gb of G. Skills Ripjaws X 1866? I took a picture with my iphone of the BIOS settings timings after i changed them, the picture is HERE. I dont know if its just me, but i think my computer is a little slower after changing the timings, so again, did i do everything right and set the right timings or possibly mess anything up in the BIOS? Thanks everyone
 

DarkDubzs

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it does say 933 and occasionally goes up a bit by like .4 so thats good that its 933. I dont see any 1T or 2T.
 
I'm not sure what's going on here.

As the G. Skill representative said, you need a 2nd stick to get full performance.

Your memory appears to be working fine other than the bottleneck by being in SINGLE CHANNEL so there's nothing you need to be doing.

You will gain very little by messing with 1T and 2T. You will gain a lot (varying by program) by using DUAL CHANNEL with two sticks.
 

Tradesman1

Legenda in Aeternum
As he said 1866 is full performance, dual channel can improve it, just as three sticks in X58 will improve it a bit more or if on X79, quad channel it will improve even more, as there are more sticks and theoretically more sticks improve performance when working as one, it doesn't increase the bandwith which remains at 1866 (and as he mentioned that's actuall M/Ts or Mega Trasfers per second. Regardless you can increase the DRAM performance primarily by lowering the CR or lowering the the CL
 


I know all that.
I just wasn't sure if he understood how little performance gain was to be had by messing around with the timings in SINGLE vs just getting another stick and going with DUAL.

I think it's best to stay with the recommended Voltage and optimal settings via XMP (SPD) to ensure system stability.

I'm pretty much done, but to be absolutely CLEAR:
*By not going DUAL CHANNEL you are absolutely creating a bottleneck between the CPU and MEMORY which will reduce performance anywhere from NONE to say 25%. It varies by the program. That's the bottom line so need to decide if the cost of going DUAL CHANNEL is worth the performance loss which again varies.