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For reference, this is the RAM that I have installed: http://www.newegg.com/Product/Product.aspx?Item=N82E16820231449

Both that page as well as the RAM stick itself say PC3 17000. However, when I use CPU-Z or Speccy to report my hardware specs, it shows the RAM as being PC3 12800 (800MHz).

Is this normal?

I'm asking because I'm wondering if all this time I've been using RAM at less than its potential. Perhaps a BIOS setting or something is limiting the RAM in some way... although I'm not sure.

My CPU is an AMD Phenom II X4 955.

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What processor are you using? –  AthomSfere Apr 2 '13 at 4:10
    
Updated post to include that. –  vertigoelectric Apr 2 '13 at 4:16
    
What motherboard are you using. The speed of your memory is depends not only on CPU support but the memory bus on the motherboard itself. –  Ramhound Apr 2 '13 at 11:17

2 Answers 2

RAM in modern system will have its FSB controlled by the CPU instead of the northbridge. AMD Calls this Hypertransport. To get the highest speed, both the CPU and the RAM must support it. Your processor will not, by default have its HT link turned that high, you will have to overclock it.

Also, FSB or Front Side bus is NOT the same thing, but I used it above to clarify the role of HT.

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I can change the HT values for the CPU. Do you know what I could/should change them to in order to get more out of my RAM? –  vertigoelectric Apr 2 '13 at 18:15
    
Its not 100% straight forward, but this should have all the answers you need: overclockers.com/forums/showpost.php?p=5985625&postcount=4 –  AthomSfere Apr 2 '13 at 18:49
    
Thanks. I'll keep that thread in mind. Unfortunately the more I dive into what it's gonna take to improve/upgrade my system, the more I find reasons to just wait until I can afford to build a new machine altogether. We'll see... –  vertigoelectric Apr 3 '13 at 10:57

RAM that requires a non-standard voltage won't use the advertised clock speeds by itself. Motherboards won't set RAM above standard voltages unless you tell it to. You need to finish the process of installing and testing your RAM. Until you confirm the clock speed, timings, and burn it in, you're not ready to boot into an OS.

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So what exactly do I need to do? I've been using this RAM for about 2 years already. –  vertigoelectric Apr 2 '13 at 4:17
    
I would forget that you've been using it for 2 years and start over as if you never installed it. Start by configuring the BIOS for the correct voltages and timings for your RAM (or use your BIOS' automatic tools if it has them) and double-check timings with memtest86+. Let memtest86+ burn the final configuration in for at least an hour, and if there are zero errors, you're good to go. –  David Schwartz Apr 2 '13 at 4:19
    
I'll give this a shot, then. –  vertigoelectric Apr 2 '13 at 4:22
    
Burn a memtest86+ CD first and make sure you can boot from it. Use an image burning program. You don't want to boot into any OS you care about until you are sure your RAM settings are solid. –  David Schwartz Apr 2 '13 at 4:24
    
I already have a copy of UBCD, which includes memtest86. Anyway, I went into BIOS to set the RAM timings but they're already auto-set to the values they're supposed to be. Another observation I made that seemed strange is that even though I have DDR3 2133 memory, BIOS reports that I have DDR3 1600. –  vertigoelectric Apr 2 '13 at 4:49

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